13
Quality Assurance of Medicines in Practice
Beverley Glass1 and Alison Haywood2
1James
Cook University,
University,
Australia
2Griffith
1. Introduction
The quality of medicines in relation to their stability has previously been seen to be entirely
the responsibility of scientists within the pharmaceutical industry. Nowadays, however,
since pharmacists have an important role to play in the delivery of safe, effective and quality
medicines (drug products), they are increasingly being required to make decisions related to
the stability of drugs in the day-to-day practice of both hospital and community pharmacy.
These decisions range from deciding on whether a liquid dosage form, extemporaneously
prepared from a commercial tablet or capsule is stable or whether it is appropriate to
repackage a drug product into a dose administration aid (DAA). Pharmacists always
consider the stability of the drug concerned and whether it might be preferable to crush a
tablet or sprinkle the contents of a capsule over food or mix it in a drink, as is common
practice in many nursing homes, when patients are unable to swallow. Pharmacists are also
required to consider the implications of the transfer to a non-manufacturer’s pack on the
stability of a drug product. Despite the widespread use of DAAs, and the common practices
of extemporaneous dispensing (compounding) and crushing tablets to be mixed with
various liquid media, there is little available data regarding the drug stability following
repackaging or alteration, involving compounding liquids or crushing of tablets.
This chapter examines the stability implications of extemporaneously prepared liquids,
tablet crushing and repackaging of tablets and capsules into DAAs, by reviewing the
literature and highlighting the research undertaken by the authors. Results from their
published data have revealed stability concerns with only 7.2% of oral liquids prepared
extemporaneously, primarily due to interactions between the drug and the excipients in the
formulation. Further research has also provided evidence on the stability of medicines
commonly repacked in DAAs to support pharmacists in making appropriate clinical and
operational decisions regarding this repackaging process.
These findings will confirm the importance of knowledge of drug stability for the practising
pharmacist, who is involved with modifying or altering drug products, whether
repackaging into DAAs, compounding oral liquids or advising on the suitability of crushing
tablets. Guidelines on appropriate practice will be provided, in addition to highlighting
challenges facing the pharmacist in continuing to deliver safe, effective and quality
medicines.
www.intechopen.com
220
Quality Assurance and Management
2. Dose administration aids
Populations are increasing in age worldwide as are the number of medicines prescribed,
with a number of these patients receiving their medication in DAAs due to the benefits in
terms of health outcomes and cost of health care. Despite the widespread use of these
devices, there is little available data on the quality implications, based on the stability of
these drug products when repackaged into such devices (Walker, 1992; Ware, Holford et al.,
1994; Nunney & Rayner, 2001; Church & Smith, 2006). Repackaging of a medicine, involving
removal from its primary packaging, invalidates the stability guarantee of the manufacturer.
In fact, drug manufacturers on the whole, tend to discourage repackaging of medicines and
as there is little quality data available to support this process. It is thus the role of the health
care team to ensure optimal patient care by making an informed judgment as to the effect on
the quality and safety of this repackaging process.
2.1 Compliance aids
Compliance aids, also referred to as Multi-Compartment Compliance Aids (MCCAs) or
DAAs (Figure 1), are devices which have been developed to assist patients in managing
their medicines by arranging individual doses according to their prescribed dose schedule
throughout the day.
Fig. 1. Examples of Compliance Aids: Webstercare Cold Seal Flexi-Pak® (left), dosette box
(right).
These aids have been used to facilitate medication administration to patients for over 30
years and their wider application has been strengthened by various government programs
worldwide to facilitate their use (Llewelyn, Mangan et al., 2010). A community pharmacy
contractual framework in the UK now places emphasis on assessing and providing practical
compliance aids to all patients who fall within the protection of the Disability
Discrimination Act 1995 and need help with medicine taking (Chan, Swinden et al., 2007).
The Australian Government Department of Health and Ageing has funded a number of
professional programs and services under the Better Community Health Initiative of the 4th
www.intechopen.com
Quality Assurance of Medicines in Practice
221
and 5th Community Pharmacy Agreements, including the DAA Program, where the dollar
value was increased from nearly $73 million to $132 million (Australian_Government, 2010).
The objective of this program is to identify patients who will derive the most benefit from
the supply of a DAA, to develop a sustainable service and payment model capable of
meeting the program’s aim and to trial the broader use of these aids within the community
setting. The provision of a DAA service through community pharmacies is expected to
reduce medication related hospitalisation and adverse events through improved medication
management. This should result in improved quality of life and health status for patients,
and have flow on benefits for the community by reducing the demand on aged care facilities
and costs associated with adverse reactions to medication mismanagement.
2.2 Stability of repackaged medicines
The stability of a pharmaceutical product may be defined as the capability of a particular
medicine, in a specified container, to remain within its physical, chemical, microbiological,
therapeutic and toxicological specifications. The shelf-life of a drug product may be affected
by the intrinsic stability of the active pharmaceutical ingredient (API) and the excipients, the
potential interactions between them, the manufacturing process, the dosage form or drug
product, and the packaging and environmental conditions encountered during their
transport, storage and use (Aulton, 2007).
Pharmaceuticals are expected to meet specifications for identity, purity, quality and strength
throughout their defined storage period. The stability of manufactured medicines is
routinely confirmed by the drug manufacturers according to international regulatory
requirements (ICH, 2003), where stability studies on packaged medicines are conducted at
real-time long-term and accelerated conditions at specific temperatures and relative
humidity (RH). This represents storage conditions experienced in the distribution chain of
the climatic zone(s) of the country or region of the world concerned. Manufacturers’
packaging is designed to protect drug products from environmental factors encountered
during storage, such as light, air (oxygen, carbon dioxide and other gases), and moisture,
while limiting interactions between the product and the packaging material. However, this
does not guarantee the stability of the API and the drug product on removal and
repackaging into a DAA. A recent survey of 392 repackaged products revealed that,
although some information regarding the potential stability of solid dosage forms in DAAs
can be obtained from manufacturers, there is still a lack of short-term stability data for the
transfer of drug products into these devices (Church & Smith, 2006). Thus, although the
benefits of the use of these devices, in terms of both health outcomes and cost of healthcare
have been reported (Simmons, Upjohn et al., 2000; Lee, Grace et al., 2006), there is little
available data regarding the shelf-life of drug products when repackaged. The fact that there
is little available stability data is significant considering the value of these aids, the
investment in dollars and the extent to which they are being used to aid adherence.
In electing to repackage a drug product into a DAA, healthcare professionals must consider
the implications on drug stability of the transfer to a non-manufacturer pack. Pharmacists
thus rely largely on individual drug storage recommendations for the medicine in the
manufactures packaging, general guidelines for repackaging, e.g. in Australia (PSA, 2007),
the UK (RPSGB, 2003) and USA (USP, 2010), and their basic understanding of inherent drug
stability to make case-by-case recommendations as to whether repackaging is appropriate. A
www.intechopen.com
222
Quality Assurance and Management
small number of medicines have been investigated for their stability following repackaging
into DAAs, namely aspirin, atenolol, clozapine, frusemide, paracetamol, prochlorperazine,
and sodium valproate (Table 1). These studies have contributed significantly to the body of
evidence available on repackaging into DAAs and are detailed below. These drug
candidates were chosen for study for a number of reasons, including that they were
commonly repackaged into DAAs, because of their proven susceptibility to various
environmental conditions and/ or because of anecdotal evidence from the practice of
problems encountered when these drugs are repackaged either from a patient or health
professional perspective.
Active Ingredient
Aspirin
Atenolol
Clozapine
Frusemide
Paracetamol
Prochlorperazine
Sodium valproate
Stability considerations
Moisture sensitive
Light sensitive
Oxygen sensitive
Light sensitive
Moisture sensitive
Light sensitive
Hygroscopic
Literature reference
(Haywood, Llewelyn et al., 2011)
(Chan, Swinden et al., 2007)
(Perks, Robertson et al., 2011)
(Bowen, Mangan et al., 2007)
(Haywood, Mangan et al., 2006)
(Glass, Mangan et al., 2009)
(Llewelyn, Mangan et al., 2010)
Table 1. Drug candidates investigated for repackaging into DAAs.
2.3 Repackaging moisture-sensitive medicines
Three studies (Haywood, Mangan et al., 2006; Llewelyn, Mangan et al., 2010; Haywood,
Llewelyn et al., 2011) have reported on the stability considerations of repackaging medicines
that are hygroscopic or sensitive to moisture. The medicines were exposed to controlled
room temperature conditions and accelerated conditions (elevated temperature and relative
humidity). The findings of all studies emphasize the importance of ensuring that these
medicines are stored in appropriate well-sealed devices. While well-sealed devices, such as
the WebsterPak® are commonly utilised in community and hospital practice, it is not
known which devices are used by patients in their homes, since many of these devices that
do not have adequate air-tight seals, such as the dosette box (Figure 1), are available in
supermarkets and general stores. One of the studies also investigated whether splitting
tablets, as is commonly undertaken by patients on low-dose Aspirin, had any adverse effects
on the stability and quality of these tablets, when repackaged.
2.3.1 Paracetamol
Haywood and colleagues (Haywood, Mangan et al., 2006) examined the stability
implications of repackaging commonly used 500 mg paracetamol tablets (Panamax, Sanofi
Synthelabo) in a DAA frequently employed in practice (Multidose WebsterPak®).
Paracetamol has the potential to undergo hydrolysis and therefore requires protection from
moisture. The samples in this study were stored under controlled long-term (25ºC; 60% RH)
and accelerated (40ºC; 75% RH) conditions as per the ICH (International Conference on
Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human
Use) guidelines for a period of three months. Physical characteristics of the tablets, including
weight uniformity, physical appearance, hardness, friability, disintegration and dissolution
were evaluated at time = 0, directly after heat sealing, 1 month and 3 months. Chemical
www.intechopen.com
Quality Assurance of Medicines in Practice
223
stability was confirmed by a validated high performance liquid chromatography (HPLC)
method. The results were compared to control samples stored in the original packaging.
The results of the study were very favourable for repackaging paracetamol, indicating that
all requirements for the physicochemical stability were met with the paracetamol content
within the required British Pharmacopoeial (BP) range of 95–105% of the labelled amount,
for all storage conditions, even those conditions of high humidity. The results suggest that
paracetamol tablets repackaged into a DAA offering sufficient protection from moisture
would remain stable for a reasonable in-use period of approximately six weeks (i.e. allowing
two weeks for advanced packing and delivery on a four-week supply).
2.3.2 Aspirin
Aspirin (acetylsalicylic acid) in low-doses has been increasingly prescribed for primary
prevention of stroke and acute myocardial infarction in the elderly. A recent study has
indicated that low-dose aspirin is also a cost-effective option in primary prevention and the
majority of healthcare systems are more than willing to pay for any additional QualityAdjusted Life Years (QALYs) gained (Annemans, Wittrup-Jensen et al., 2010). It is often
more cost-effective for patients to purchase standard dose (300 mg) aspirin and to cut the
tablet in half to achieve a ‘low-dose’ equivalent. Tablet splitting or dividing has been an
accepted practice for many years as a means of obtaining the prescribed dose of a
medication and for cost-saving purposes (Marriott & Nation, 2002). However, the storage of
split tablets is not well discussed in the literature and anecdotal evidence suggests that
especially elderly patients or their carers split tablets in advance and then store the split
tablets in bottles that previously contained the same medication, a different medication or
some other substance, or in a compliance aid such as a dosette box (Marriott & Nation,
2002). Due to stability concerns, patients and carers are usually advised that when half a
tablet is taken, the unused half should be immediately discarded, particularly with
medicines that are known to be unstable when exposed to light and air.
Considering the above practices and the fact that acetylsalicylic acid is rapidly hydrolysed to
salicylic acid on exposure to moisture, a recent study assessed the stability of 300 mg aspirin
tablets (Solprin Dispersible Tablets, Reckitt Benckiser) when repackaged in a dosette box
obtained from a local supermarket and stored under a number of in-use conditions, both as
a whole and split tablet (Haywood, Llewelyn et al., 2011). This is an important consideration
as it is a decision to be made in practice by pharmacists or at home by patients and carers.
The acetylsalicylic acid content remained within BP specifications (95–105% of the labelled
amount) for all except the accelerated storage conditions, with 93.4% of the drug remaining
in this case, and the salicylic acid content at 0.04% (BP limit 0.0006%). The split tablets did
not display any additional degradation of the acetylsalicylic acid or increased amount of the
degradant salicylic acid, when compared to the whole tablets under the same conditions.
While the acetylsalicylic acid content remained within specifications under standard room
conditions, it must be noted that the limit for the degradant was exceeded under all
conditions. Additionally there was some colouration and disintegration of the tablets, thus
compromising the quality of this medication and suggesting that this practice of
repackaging by patients is inappropriate. This study in fact does confirm the instructions
given that these dispersible tablets should not be removed from their original packaging and
that if tablets are split, that the remaining half should be discarded.
www.intechopen.com
224
Quality Assurance and Management
2.3.3 Sodium valproate
Llewelyn and colleagues (Llewelyn, Mangan et al., 2010) undertook a study on the stability
of 100 mg sodium valproate tablets (Epilim, Sanofi-Aventis) repackaged into DAAs
(WebsterPak®) and stored under various temperature and humidity conditions. Sodium
valproate, a commonly used antiepileptic is unstable in the presence of moisture due to its
hygroscopic and deliquescent nature. The results revealed that while the sodium valproate
content in the tablets remained within an acceptable range (90–110% of the labelled amount)
under all storage conditions for eight weeks, the physical stability was not maintained, with
unacceptable weight variation in the tablets, changes in their dissolution profiles and
significant changes in their appearance, under accelerated conditions, due to the
hygroscopicity of the API, even after only three weeks of storage (Figure 2) (Llewelyn,
Mangan et al., 2010).
Fig. 2. Sodium valproate tablets after 21 days of storage at accelerated (40ºC; 75% RH) (left),
refrigerated (2–8ºC) (middle) and controlled room temperature (25ºC) (right) conditions.
The results of this study highlight the fact that accelerated conditions of temperature and
humidity should be taken into account, and that cognisance is taken from the fact that in
different countries, and in fact within the same country, the climatic conditions might vary
considerably. Medicines therefore may be appropriately repackaged in, for example, a
temperate region such as London, Los Angeles or Sydney, but repackaging that same
medicine in tropical or desert regions such as Darwin or Dubai may be inappropriate due to
increased temperature, humidity and light conditions. These findings are thus significant
because these accelerated conditions are not uncommonly encountered in northern
Australia and other tropical regions worldwide.
2.4 Repackaging light-sensitive medicines
Three studies (Bowen, Mangan et al., 2007; Chan, Swinden et al., 2007; Glass, Mangan et al.,
2009) have reported on the stability considerations of repackaging medicines that are
sensitive to light. The medicines were exposed to controlled room temperature conditions
(25ºC; 60% RH) and accelerated conditions (40ºC; 75% RH) and two of the studies also
included those light conditions specified by the ICH (ICH, 1996).
2.4.1 Atenolol
Atenolol is reported to be photoreactive when exposed to UVA–UVB radiation with
photodegradation increasing with a decrease in the pH value (Aryal & Skalko-Basnet, 2008).
www.intechopen.com
225
Quality Assurance of Medicines in Practice
The main photodegradation product at pH 7.4 has been identified as 2-(4-hydroxyphenyl)
acetamide (Andrisano, Gotti et al., 1999) (Figure 3).
NH2
CH3
H3C
N
H
O
O
OH
OH
+
CH2CONH2
NH2
CH3
H3C
N
H
O
O
Fig. 3. Photodegradation of atenolol
Chan and colleagues (Chan, Swinden et al., 2007) reported on the stability of atenolol 100
mg tablets in a 28-chamber compliance aid with transparent lids, stored for four weeks at
room temperature (25ºC; 60% RH) and accelerated (40ºC; 75% RH) conditions. Tablets were
also stored at room temperature in their original packaging and in Petri dishes. All tablets
stored at room temperature conditions passed the necessary physical tests (weight
uniformity, physical appearance, hardness, friability, disintegration and dissolution) and
demonstrated chemical stability, however the tablets stored at accelerated conditions
although chemically stable, showed an increase in disintegration time and decreased
dissolution time when compared to the tablets stored in the original blister packaging. A
limitation of the study was that only one sampling time point (Week 4) was used with
comparison of the results to the tablets stored in the original packaging, as opposed to
observing changes from an analytical determination at the outset (time = 0). Further, the
brand of the compliance aid or the degree of protection afforded against air, moisture and
light is unknown (Glass, Haywood et al., 2009).
2.4.2 Frusemide
Frusemide, a light sensitive drug commonly used in the treatment of cardiac failure and
hypertension is often repacked into a DAA. A study by Bowen and colleagues (Bowen,
Mangan et al., 2007) reported on the in-use stability implications of repackaging 40 mg
frusemide tablets (Uremide, Alphapharm). In addition to storing the medicines under
controlled room temperature conditions (25ºC; 60% RH), the DAAs (WebsterPak®) were
stored for eight weeks under conditions that reflected a ‘home-environment’ where DAAs
were stored blister-side up in a bathroom exposed to a standard 60W tungsten bulb and
indoor indirect daylight/ window- filtered sunlight; and a ‘pharmacy-environment’ where
DAAs were stored blister-side up on a bench top exposed to fluorescent lighting and indoor
www.intechopen.com
226
Quality Assurance and Management
indirect daylight. Photostability studies were also performed according to the ICH
guidelines (ICH, 1996). The results confirmed the drug content to be within the BP range of
95–105% for all storage conditions, including the ICH light conditions. Although the
physical stability was confirmed by all tests, including weight uniformity, hardness,
friability, disintegration, dissolution, under both controlled and in-use conditions, the
exposure to light in the pharmacy and under ICH conditions, even after one week, resulted
in a yellow colouration of the tablets. The progressive yellow discolouration (Figure 4)
(Bowen, Mangan et al., 2007) of the tablets over an eight week storage period was attributed
to exposure to fluorescent lighting, which was not encountered under the ‘homeconditions’. Although the colour change was noted as having negligible effects on the drug
content and other physical parameters, such as dissolution of the tablets, it was considered
an unacceptable change, since patients are likely to be concerned about a possible
compromise in the quality of the medicine, and this may have an adverse effect on patient
acceptance and hence adherence.
Fig. 4. Progression of colouration of frusemide tablets exposed to fluorescent lighting over
an eight week period from left (week 1) to right (week 8)
2.4.3 Prochlorperazine
Prochlorperazine, a phenothiazine drug, widely used as an anti-emetic is susceptible to
oxidation to the sulphoxide (a metabolite and a photodegradant) under the influence of
light (Figure 5). The main metabolites and degradants of all phenothiazines have been
found to be inactive at the dopamine receptors (Nejmeh & Pilpel, 1978; Moore & Tamat,
1980) and prochlorperazine is reported to cause photosensitivity effects in patients. A
study by Glass and colleagues (Glass, Mangan et al., 2009) reported on the
physicochemical stability of 5 mg prochlorperazine tablets (Stemetil, Sanofi-Aventis)
repackaged into a DAA (WebsterPak®). In addition to the controlled room temperature
(25ºC; 60% RH) and accelerated (40ºC; 75% RH) storage conditions, tablets were also
exposed to an in-use condition by placing the repackaged DAAs blister-side up on a
bench top exposed to fluorescent lighting and indoor indirect daylight. The results
showed chemical and physical stability to be within BP limits (drug content within 95–
105%) however, there were noticeable organoleptic changes in the tablets stored under the
in-use conditions, with a progressive grey discolouration over an eight week period,
starting in week 2. The discolouration and the potential for the resulting photodegradants
to cause adverse effects in patients suggest that the quality of this medicine had been
compromised.
www.intechopen.com
227
Quality Assurance of Medicines in Practice
H3C
H3C
N
N
sulphoxidation
N
N
N
N
Cl
Cl
S
S
O
H3C
photo-substitution
/ reduction
N
N
N
(OH)H
S
Fig. 5. Photodegradation of prochlorperazine
2.5 Repackaging medicines sensitive to oxidation
Only one study (Perks, Robertson et al., 2011) has reported on the stability of repackaging
medicines sensitive to oxidation, with preliminary findings suggesting that clozapine
undergoes a photo-oxidative process, since the coloration is not apparent during the
exposure period in the absence of light.
2.5.1 Clozapine
Clozapine is an atypical antipsychotic used in the treatment of schizophrenia. A study by
Perks and colleagues (Perks, Robertson et al., 2011) was prompted due to anecdotal reports
from hospital pharmacy practice about discolouration of returned clozapine tablets that
were repackaged into DAAs, and the known susceptibility of clozapine to oxidation
(Kohara, Koyama et al., 2002). The study evaluated both the chemical content and physical
stability of clozapine tablets (Clopine, Hospira, and Clozaril, Novartis) repackaged into a
DAA (WebsterPak®) over a six week period. The DAA’s were stored under two
environmental conditions, namely accelerated conditions (40ºC; 75% RH), and under a
simulated controlled room temperature condition (25ºC; 60% RH) by placing the DAA with
the blister-side facing up on a windowsill in the laboratory, with exposure to both windowfiltered sunlight and fluorescent light. The results were compared to control samples stored
in the original packaging under the above conditions. The study also investigated the
stability of the tablets exposed to ICH light conditions (ICH, 1996). Although the physical
stability, namely weight uniformity, hardness, friability, disintegration and dissolution, was
confirmed for all tests at room temperature, under accelerated conditions, the disintegration
test did not meet the BP requirements. However, the subsequent dissolution test was
successful with 85% of clozapine dissolving in 45 minutes. The chemical stability was
confirmed for all storage conditions, including under ICH conditions (for light), with
clozapine content within the BP range of 90–110%.
www.intechopen.com
228
Quality Assurance and Management
Based on the susceptibility to oxidation, and in order to reproduce the colouration noted in
the practice of repackaged samples returned by patients, a sample was removed from the
original manufacturers packaging and exposed to light and air on the bench beside the
simulated controlled room temperature condition samples (Figure 6) (Perks, Robertson et
al., 2011). The results for the exposed tablets confirmed the discolouration referred to in the
anecdotal reports from practice. These findings show that clozapine, when correctly
repackaged, maintained its physical and chemical stability for six weeks. It is therefore
assumed that these reports of tablet discoloration were as a result of improper handling of
these DAAs by patients. These findings highlight the importance of the role of the
pharmacist in providing patient care and advising on the correct handling and storage of
their DAAs.
Fig. 6. Photographic comparison of the colour of clozapine tablets from left to right: control
sample, sample stored in a DAA under simulated controlled room temperature conditions
after 6 weeks, and a sample left out of the DAA packaging on the windowsill after 6 weeks
(Clopine® above and Clozaril® below)
2.6 General guidelines for repackaging medicines
Various published guidelines, such as the Pharmaceutical Society of Australia (PSA)
Professional Practice Standards (PSA, 2010) and Dose Administration Aids Service
Guidelines and Standards for Pharmacists (PSA, 2007) have provided general guidance on
the suitability of repackaging of solid dosage (tablets and capsules) forms into DAAs and
are summarised in Table 2.
A flow chart for the quality management of DAAs in practice is shown in Figure 7
(Haywood, Llewelyn et al., 2011).
The following practical recommendations for ensuring the quality and stability of medicines
repackaged into DAAs arising from the above studies include: (i) selecting an appropriate
brand of DAA for repackaging medicines that affords appropriate protection against air and
moisture; (ii) protecting the DAA containing drugs susceptible to photodegradation from
light in the pharmacy and in patients’ homes, achieved by either storing the DAA protected
from light and/or placing the DAA into a light-protecting sleeve (e.g. foil, cardboard); (iii)
careful removal of tablets to prevent accidental rupture of adjacent blisters, thus exposing
tablets to air and moisture; (iv) monitoring the DAA integrity during repackaging,
dispensing and throughout the in-use period; (v) consideration of an appropriate location to
www.intechopen.com
Quality Assurance of Medicines in Practice
229
store the DAA to avoid unnecessary exposure to light, heat, humidity and away from
children, if the device is not child-resistant; (vi) counselling patients on correct use and
appropriate storage locations for their DAA; and (vii) following appropriate professional
practice guidelines (Haywood, Llewelyn et al., 2011).
Medicines generally unsuitable for packing into DAAs include effervescent, dispersible,
buccal and sublingual tablets and significantly hygroscopic preparations.
Medicines administered on an ‘as required’ basis are generally unsuitable for packing into
DAAs, since they may be taken unnecessarily on a regular basis or removed for use at an
earlier or later stage, thus exposing the remaining contents to the environment.
Cytotoxic preparations or other medicines posing occupational health and safety risks are
generally inappropriate, however the risk-benefit of packing must be considered; for
example, packing may be appropriate where non-adherence is considered to be a greater
risk.
Only devices that are well sealed and tamper evident should be used.
The length of time taken for the end-to-end packing process should be kept to a minimum;
tablets and capsules should be removed from the manufacturer’s foil or blister pack
immediately before the DAA is packed, and the DAA sealed immediately after it is
packed.
Any heat sealing methods should be used quickly and efficiently to minimise exposure of
medicines to heat, the likely storage conditions (e.g. exposure to heat, humidity, and
moisture) and the length of time the DAA will be in transit.
It is useful to maintain a list of medicines / medicine types that should not be removed
from their original pack for repacking in a DAA.
Table 2. Summary of PSA guidelines relating to the suitability of repackaging into DAAs
Choice of an appropriate DAA
1. DAA must be well sealed to protect against air and moisture.
Appropriate choice of medicine
1. Consult manufacturer information.
2. Cytotoxic, effervescent, dispersible, hygroscopic, sublingual or buccal
medicines are not recommended.
Counsel patients and carers
1. Store DAA protected from light, heat and humidity.
2. Monitor the integrity of the DAA.
3. Caution not to rupture adjacent blisters when removing tablets.
Fig. 7. DAAs – Assuring quality in practice.
www.intechopen.com
230
Quality Assurance and Management
3. Crushing tablets
The world’s population is ageing and many patients suffer from dysphagia either as a
consequence of disease or as part of the ageing process. Elderly patients are more prone to
diseases linked to dysphagia, such as Parkinson’s and Alzheimer’s disease, other dementias,
stroke and cancer (Morris, 2005). Further, several age-related changes may contribute to
dysphagia, including a decline in salivary gland function resulting in xerostomia, and
changes in the sensory function of the aerodigestive tract such as a deterioration of the
pharyngo-upper esophageal sphincter (UES) and laryngo-UES contractile reflexes
(Kawamura, Easterling et al., 2004). Polypharmacy, involving the use of multiple medicines
at the same time, is common among older patients. Dysphagia therefore poses significant
challenges for medicine administration, since most adult medicines are available as mainly
solid dosage forms (i.e. tablets or capsules).
Tablets and capsules are commonly modified or altered for ease of administration, not only
in traditional care settings such as residential aged care facilities and in hospital wards, but
also by patients experiencing swallowing difficulties at home. Opening a capsule or
crushing a tablet before administration will in most cases render its use to be ‘unlicensed’. In
addition to the legal implications involved in modifying medicines, there are important
safety, stability and bioavailability considerations. Pharmacists thus have a role to play in
advising not only on safe medicine use but on any stability issues which may occur on
modifying oral solid dosage forms and thus contribute to improving the quality use of
medicines in older patients.
3.1 Medicines that should not be crushed
There are certain tablets and capsules that should not be modified. The potential risks
associated with crushing tablets and opening capsules and the impact on the API is
summarised in Table 3 (Haywood & Glass, 2009). Important considerations include
(Haywood & Glass, 2009):
•
•
•
Controlled or sustained release medicines are designed to release the active ingredient
in a controlled manner over a defined dosing period. Crushing or splitting these drug
products will interfere with the release characteristics and usually cause an unintended
large bolus dose resulting in toxicity and increased incidence of adverse effects. For
example, crushing sustained release verapamil (e.g. Veracaps SR®) will result in an
increased risk of hypotension and bradycardia.
Enteric coating is used to protect the active ingredient from the acidic environment of
the stomach and film coating affords protection from light. Tablets, capsules and
capsule contents such as pellets can contain these coatings. For example, nifedipine (e.g.
Adalat®) is extremely susceptible to light and even brief exposure to ambient light will
result in degradation of the API. Omeprazole (e.g. Losec®) is degraded by exposure to
acid and whilst the tablets may be dispersed in yoghurt or orange juice, crushing such
tablets will expose the API to acid in the stomach resulting in a loss of activity before
the site of absorption in the upper small intestine.
Delayed release medicines are designed to release the API at a defined site in the
gastrointestinal tract. For example, mesalazine (e.g. Mesasal®) is formulated as a resin
coated tablet designed to dissolve and release medication in the lower small intestine,
where it exerts a local anti-inflammatory effect.
www.intechopen.com
231
Quality Assurance of Medicines in Practice
•
•
•
Enteric coated tablets, for example Cartia®, are designed to minimise the irritant effect
of aspirin. If these tablets are crushed, they may be irritant to the oesophagus and the
stomach (upper gastrointestinal tract).
Sugar or film coats are designed to disguise APIs with an unacceptable taste. For
example, quinine (e.g. Quinate®) is coated to disguise the bitter taste. Crushing these
tablets, although not altering their effectiveness, may compromise patient adherence.
There are occupational health and safety (OH&S) concerns with not only cytotoxic
medicines, but also teratogens (e.g. isotretinoin) and those medicines with the potential
to cause contact dermatitis (e.g. chlorpromazine). It is important to remember that the
clinical indications for the use of some cytotoxics extend beyond the treatment of
malignancy, for example, cyclophosphamide (e.g. Cycloblastin®) and methotrexate (e.g.
Methoblastin®) are used to treat some inflammatory disorders. Health care workers
and carers need to take appropriate measures to avoid exposure to the powder from
these crushed tablets.
Dosage forms that should not be crushed
Extended/ sustained-release product
Enteric coat protecting an acid-labile API
Film coat protecting a light-sensitive API
Delayed-release coat designed to release API at a
defined site in the GIT
Enteric coat protecting the upper GIT from the API
Sugar/ film coat disguising a poor tasting API
OH&S of cytotoxic/ teratogenic APIs
Potential risks
Increased toxicity/ adverse effects
Decreased stability/ efficacy
Decreased stability/ efficacy
Decreased efficacy
Increased local irritant effect
Unacceptable taste/ poor compliance
Potential hazards to health care
workers and careres
Table 3. Risks associated with modifying tablets and capsules
Information on the appropriateness of modifying oral solid dosage forms is available
through resources such as the approved product information and the CMI (Consumer
Medicine Information) of the medicine. Compiled lists of medicines that should not be
crushed or modified are available, such as the Handbook of Drug Administration via
Enteral Feeding Tubes (White & Bradnam, 2007), the Australian Pharmaceutical Advisory
Council (APAC) Guidelines for medication management in residential aged care facilities
(Appendix F) (APAC, 2002), the Australian Medicines Handbook (AMH) Aged Care
Companion (AMH, 2006) and electronic resources such as the list provided by the Institute
for Safe Medication Practices (Mitchell, 2011). Many hospitals and aged care facilities have
also developed their own lists. These lists, while providing a useful starting point, should
not be relied upon as being all inclusive.
3.2 General guidelines for safe medicine use when modifying medicines
Pharmacists are able to play an important role in educating patients, carers and other health
care professionals concerning the safe and effective administration of medicines. There are
reported cases of fatalities that have occurred, not only in traditional care settings, for
example where a patient was administered crushed controlled release tablets via a
nasogatric tube (Schier, Howland et al., 2003), but also in the patients’ home, where a patient
www.intechopen.com
232
Quality Assurance and Management
chewed extended release diltiazem capsules, since they were too large to swallow (Ballard,
1996). This highlights the importance of patient counselling in a community setting, since
pharmacists may be unaware of the medication administration techniques and practices
adopted by patients at home.
The APAC guidelines for altering medicines (APAC, 2002) provide a six-step process,
summarised in Figure 8 (Haywood & Glass, 2009), to ensure that patients receive the desired
therapeutic response from their medicines.
1. Assessment of swallowing ability
2. Review of medication regimen
3. Which formulations should not be modified?
4. Suitable techniques for crushing
5. Administration of modified medicines
6. Monitoring and assessment
Fig. 8. Six-step process to ensure desired therapeutic response
3.2.1 Medication management, monitoring and assessment
There are many important considerations when administering modified medicines, either
by the patient themselves at home, or with the assistance of carers or health care
professionals in hospitals and aged care facilities.
A patient’s swallowing ability should be carefully assessed since their ability to swallow
may be a transient disability or may vary during the day. Changing the dosing time and
renewed attempts to encourage taking unaltered dosage forms should be the first option,
whenever possible. Instinctively, most patients will tip their head backwards when
swallowing a tablet, but this actually narrows the oesophagus, making swallowing more
difficult. Patients should tilt their head down rather than back as this will widen the
oesophagus and may remedy difficulties in taking tablets. The use of liquid ‘chasers’ or
swallowing tablets ‘chased’ by a few bites of a well chewed banana or soft food (e.g. bread)
may be of assistance in some cases. Wherever possible patients should be upright, or as
close as practically possible to upright when taking oral medicines. Patients who are unable
www.intechopen.com
Quality Assurance of Medicines in Practice
233
to swallow may be able to take medicines that are not swallowed but are absorbed
sublingually (e.g. glyceryl trinitrate tablets) or sucked (e.g. amphotericin lozenges)
(Haywood & Glass, 2009).
Difficulties seen in swallowing oral medicines should provide a stimulus for a medication
review. Various options should be considered prior to modifying a medicine, including:
changing to a different formulation of the same medicine (e.g. oral liquids/drops,
dispersible tablets or transdermal patches); seeking a therapeutic alternative in an
appropriate dosage form; or stopping medicines that are no longer necessary. In cases where
a different formulation or therapeutic alternative is not available, and a sustained-release
product is prescribed, it may be necessary to administer an immediate-release preparation
more often, for example immediate release verapamil tablets are usually given three times a
day as opposed to once daily administration for the slow-release (SR) preparation, since
these preparations can usually be crushed and also more cost-effective. Monitoring and
assessing the therapeutic response is especially important when medicines are modified.
Adverse effects or lack of expected effects should trigger a review of this practice (Haywood
& Glass, 2009).
3.2.2 Techniques for crushing tablets
Appropriate equipment that is non porous and permits complete and reproducible
recovery of powdered material should be used, such as a mortar and pestle or appropriate
commercially available tablet crusher, to avoid dose inaccuracies. Equipment should be
washed and dried between uses to prevent cross contamination. Cytotoxic medicines
should have a dedicated set of equipment and special procedures must be adopted to
minimise occupational exposure, for example a mortar and pestle enclosed in a
transparent plastic bag with the operator wearing a mask and gloves (Haywood & Glass,
2009). Mixing powdered material with a small amount of food that the patient likes (e.g.
jams, fruit purees) is sensible as it disguises unpleasant taste and aids in compliance. The
crushed tablets or capsule contents should be given to the patient as soon as possible after
crushing and mixing with any food or liquid, as this will minimise both the risk of
medication degradation and, in an aged care setting, inadvertent administration to the
wrong resident. Crushed tablets or contents of capsules should not be sprinkled onto
meals where portions of the meal may be left uneaten, resulting in under dosing. Further
practical guidelines to assist in safely modifying medicines are described by Haywood et
al (Haywood & Glass, 2009).
3.2.3 Counseling and continuing education
It is important for pharmacists to develop and maintain a current list that is specific to their
practice setting and is readily accessible to staff involved in patient counselling or
administration of modified medicines. However, with the frequent addition of new
medicines to the market and the challenge of maintaining an all-inclusive ‘list’, it is more
important to educate patients, carers, staff and other health care professionals about safe
medicine use and to provide them with a background concerning the safety and stability
considerations of modifying medicines to ensure the quality use of medicines so that
patients receive the best possible therapeutic outcome (Haywood & Glass, 2009).
www.intechopen.com
234
Quality Assurance and Management
4. Oral liquids in practice
The pharmacist, both in community and hospital pharmacy practice, is often challenged
with the preparation of a liquid dosage form not available commercially for paediatric
patients, those adults unable to swallow tablets or capsules, patients who must receive
medications via nasogastric or gastrostomy tubes, and patients who require non-standard
doses that are more easily and accurately measured by using a liquid formulation. It is
common practice for these liquid dosage forms to be prepared from a commercially
available solid dosage form such as a tablet/capsule. Although a number of parameters
need to be considered in the formulation of a stable liquid dosage form, there is limited
formulation and stability data available (Glass & Haywood, 2006).
4.1 Compounding pediatric mixtures
Children often require titratable individualised doses in milligrams per kilogram of body
weight and most children under six years of age cannot swallow tablets (Nahata & Morosco,
2003). There are a limited number of suitable dosage forms commercially available for
children due to the size of the market and resulting lack of financial viability for the
pharmaceutical industry of these liquid dosage forms. In addition, there are complexities
associated with the formulation of liquid dosage forms due to various physicochemical
factors. The preparation of extemporaneous oral liquids, by pharmacists, recently reviewed
by Nahata (Nahata & Allen, 2008) and Giam (Giam & McLachlan, 2008), therefore provides
an appropriate solution to this problem. The following sections provide information on the
preparation of safe, stable oral liquids for children and adults in those cases where suitable
dosage forms are not available.
4.2 Physicochemical stability considerations in compounding oral liquids
Drug stability encompasses chemical, physical, microbiological, therapeutic and
toxicological stability not only of the drug substance, but when taking account of the
excipients, also the drug product. The extemporaneous preparation of oral liquids can be
complex due to the addition of excipients to improve compliance or the stability of the final
product. Further, if oral liquids are prepared from a commercially available solid dosage
form such as a tablet or capsule, there may be potential interactions between the drug and
the excipients (in the commercial product) in the prepared oral liquid. Such interactions may
involve the vehicle, preservative, buffering agent, flavouring agent, wetting and suspending
agent, viscosity enhancer or even the storage container. However, a review in 2006 of 83 oral
liquids extemporaneously prepared by modifying an existing commercial dosage form
revealed that only 7.2% of those compounded oral liquids exhibited stability concerns (Glass
& Haywood, 2006). This review is a useful comprehensive summary of liquid dosage forms
prepared from commercially available tablets or capsules and illustrates the low risk
associated with these products, if cognisance is taken not only of the API but all those
excipients present in the commercial dosage form, used in their preparation.
4.2.1 Active ingredient and excipients
In most practice settings, sourcing the API as a powdered raw material is not always
practical and thus commercially available tablets and capsules are often used in
www.intechopen.com
Quality Assurance of Medicines in Practice
235
compounding oral liquids. These solid dosage forms however contain many excipients,
which although compatible in the solid state have the potential to interact both in solution
or suspension, adversely affecting the potency of the API and thus impacting on the shelflife of the compounded oral liquid. There are also certain tablets that should not be crushed
and these are detailed in section 3 above. Excipients used in extemporaneous oral liquids
commonly include suspending agents or viscosity enhancers, sweeteners and preservatives.
They may also contain flavours, colours and buffers. It is not always necessary to colour a
product. If a colouring agent is used, it should match the flavour (e.g. red for cherry) and
should be used in minimal quantities to produce light-moderate density colours. The
Therapeutics Goods Administration (TGA) has a recently updated list of colourings
permitted in oral medicines (TGA, 2011). Mixtures may be required to be buffered to an
optimum pH, or pH might need to be taken into account when using certain preservatives
(e.g. benzoic acid) which require an acidic pH to be effective. Commercial liquid vehicles,
that contain a combination of sweeteners, flavours, viscosity enhancers or suspending
agents and preservatives are available. Some contain non-nutritive sweeteners and are
therefore suitable for diabetic patients. Many stability studies are available in the literature
that utilise these commercial liquid vehicles, thereby making them a convenient resource,
especially since various practice settings may not hold a wide variety of excipients in stock
(Haywood & Glass, 2010).
4.2.2 Designing an oral liquid formulation
Pharmacists should be encouraged to use the following process to assist in the
compounding of safe, stable oral liquids (Figure 9) (Haywood & Glass, 2010). In the absence
of existing commercially available dosage forms or therapeutic alternatives in a suitable
dosage form, a compounded oral liquid is best prepared by searching for a suitable formula.
It is important that the stability of these compounded oral liquids is evaluated by methods
of analysis that are ‘stability-indicating’ (Prankerd, 2009). Examples of Journals containing
stability-indicating methods of analysis include: Journal of Pharmacy Practice and Research,
International Journal of Pharmaceutical Compounding, and the Journal of American Health-System
Pharmacists. However, a suitable search engine will provide results from a wider range of
journals. For example Medline (http://www.ncbi.nlm.nih.gov/pubmed) and Google scholar
(http://scholar.google.com.au/schhp?hl=en&tab=ws) are free-access online search engines.
Useful texts include: Allen’s Compounded Formulations (Allen, 2003), Paediatric Drug
Formulations (Nahata, Pai et al., 2004), Stability of Compounded Formulations (Trissel,
2009), however it is important to check whether there is evidence for the stability of these
formulations (Haywood & Glass, 2010).
Should no suitable formula be available in the literature, pharmacists may be required to
design a formula from first principles. Designing an oral liquid, using sound scientific
principles, is a lengthy process and would require careful consideration of a number of
factors including: potential degradation of the active API by pathways such as oxidation,
hydrolysis, photolysis or thermolysis; storage, preservation and packaging considerations
and assigning a suitable shelf-life to the formulation; and interactions between excipients
and the API, especially if tablets or capsules are used as the source. The manufacturer of the
solid dosage form may be able to provide useful stability data for the API. Generally, a
commercial liquid vehicle would be the preferred choice, since it would contain all the
www.intechopen.com
236
Quality Assurance and Management
necessary excipients to formulate the oral liquid. It is also preferable to obtain the API in
pure powder form as opposed to using a commercial product, since the excipients in the
commercial product will add to the complexity of the final product. The final product
should be packaged in a light-resistant container (since many colours and flavours are
sensitive to light) with a child-resistant cap and be appropriately labelled (Haywood &
Glass, 2010).
Is there a suitable commercially available product?
Is there a therapeutic alternative available in a suitable dosage form?
Is there a published formula for a compounded oral liquid?
– Compendia
– Journals
– Reference Texts
Design a formula from first principles
Fig. 9. Compounding safe, stable oral liquids.
4.2.3 Caution when modifying existing formulae
Because of the ability of excipients in tablets and capsules to interact with the API in the
liquid dosage form, there are problems associated with using stability data for an oral liquid
made from powdered raw material and in making the assumption that oral liquids prepared
from commercial tablets or capsules will have comparable stability and thus shelf life. This
was demonstrated in a study investigating the stability of an isoniazid (INH) liquid
prepared using commercially available tablets and a British Pharmaceutical Codex (BPC)
formula, where significant degradation of the INH (≥ 10 % after 3 days at both 4 and 25 ºC)
was shown whereas the control (using pure INH powder) retained the desired stability of >
90 % after 30 days, as specified in the BPC, under identical conditions (Haywood, Mangan et
al., 2005). A replicate control formulation spiked with lactose (an excipient present in the
commercial tablets), produced similar degradation profiles to that of the compounded oral
liquid. INH is susceptible to hydrolysis and oxidation and is known to interact with
reducing sugars (e.g. lactose), to form hydrazines (Figure 10). Although the BPC claimed 28
days stability for the extemporaneously prepared INH mixture, the use of INH powder, as
opposed to INH tablets, was specified. This highlights the importance of considering not
only the stability of the API but also the potential for interaction with excipients when
modifying existing formulae.
www.intechopen.com
237
Quality Assurance of Medicines in Practice
N
+
CH2OH
OH
O
OH
CH2OH
O
O
OH
OH
H2N
N
H
O
OH
OH
1-isonicotinoyl-2-lactosylhydrazine
Fig. 10. Degradation of isoniazid in the presence of lactose.
The stability of a drug substance in an extemporaneous oral liquid can be compromised by
the addition of excipients. When considering the safety and efficacy of oral liquids prepared
extemporaneously, it is important to consider not only the stability of the API but the entire
formulation. Pharmacists are to be encouraged that by considering various factors such as
drug stability, mechanisms and pathways of degradation, potential interactions with
excipients in the tablets or capsules, and the availability of formulae (including methods and
materials) for stable liquid dosage forms for oral administration in the literature, they are
able to confidently dispense an oral liquid dosage form. However, clinical experience,
including an assessment of bioavailability whenever possible, with extemporaneous liquid
dosage forms for oral administration should be reported in the literature to further support
health professionals in this important area of practice.
5. Repackaging and storage of medicines in developing countries
Solid dosage forms such as tablets are commonly procured in bulk and repackaged in
developing countries in order control costs and therefore to ensure that governments are
able to provide medicines to a large majority of the population. This repackaging process
involving removal the drug from its primary packaging invalidates the stability guarantee
of the manufacturer and often involves the transfer of the tablets to a small ‘bank bag’
which may be clear, opaque white, yellow, brown or red and manufactured from
polyvinylchloride (Figure 11). Although the pharmaceutical industry is required to assure
the stability of drugs under certain conditions of temperature light and humidity, these
conditions may not be inclusive of in-use conditions. These in-use conditions may relate to
accelerated temperature, light and humidity conditions, but may also simply be due to the
fact that a request to store a drug product under refrigerated conditions cannot be adhered
to in the a developing country, due to the patient simply not having access to a refrigerator.
Fig. 11. Examples of Bank Bags (re-sealable polyethylene bags for dispensing tablets) –
Stripform® Packaging.
www.intechopen.com
238
Quality Assurance and Management
5.1 In-use stability guidelines
Although the ICH Guideline on Photostability (ICH, 1996), describes a protocol for testing
the stability to light of both the drug substance and drug product, it fails to provide a
protocol for photostability testing under patient in-use conditions. Since this guideline was
published in 1996 and has been implemented in the US, EU and Japan and the
Pharmaceutical Industry has experience in these testing procedures, it has been suggested
by Baertschi et al (Baertschi, Alsante et al., 2010), that the time has come to revise these
guidelines to accommodate in-use conditions. Although the aim of photostability testing is
that it should show that exposure to light does not result in an unacceptable change in both
the drug substance and the drug product, by excluding any in-use testing the quality of the
product to the end consumer, the patient could be compromised. Figure 12 represents a
sequential testing which provides some recommendations as to those drug substances and
products which are not included in the guideline such as topical agents e.g. creams,
transdermal patches and intravenous preparations. There is however no reason why this
should not be extended to the repackaging of oral solid dosage forms such as tablets and
capsules and apply to all stability testing protocols, including in addition to light,
appropriate in-use conditions of temperature and humidity. Lagrange has concurred with
the findings by Baertschi et al, in a review on the current perspectives on the repackaging of
solid oral dosage forms and stability implications for this process (Lagrange, 2010).
Recognising the lack of availability of stability data, they are proposing that factors such as
the barrier properties of the packaging materials, the hygroscopicity and light sensitivity of
drug molecules and any pre-formulation stability data should be used to generate a list of
drugs which should not be repackaged. Because of the advantages associated with the
repackaging of drugs into compliance aids, they do recommend that it is the pharmacist
who is required to assess the risk of this process.
STEP 1: Is the medicine stable when exposed to light unpacked – if YES to STEP 2
STEP 2: Is the medicine stable when exposed to light in primary pack – if YES to Step 3
STEP 3: Is the medicine stable when exposed to light in secondary pack – if YES to Step 4
STEP 4: Do not transfer to a less protective pack in community/hopsital pharmacy practice
Fig. 12. Sequential photostability testing protocol
5.2 Risks and benefits associated with repackaging in developing countries
The obvious benefits associated with repackaging of medicines in developing countries are
that of cost-reduction due to bulk purchases of drug products. However the risks associated
with repackaging reported in the literature have to a large extent been centred on issues
www.intechopen.com
Quality Assurance of Medicines in Practice
239
other than drug quality in terms of stability considerations and include (Leon Villar, Iranzo
Fernandez et al., 2001; Kelly & Vaida, 2003): (i) medication errors in the repackaging of
medicines; (ii) high cost of repackaging low-quantity prescriptions, which might lead to
greater cost due to damage of the packaging by typing directly onto the label; and (iii)
expiry dates may be extended beyond what is safe for the patient. Strategies may be
implemented in order to avoid repackaging errors, including training pharmacy staff on
safety issues, and storage and labelling of drug products in the pharmacy, also referred to as
the design of a quality control line. The United States Pharmacopoeia (USP) standards on
packaging of drug products, expiry dates and monitoring of temperature conditions have
also been revised (Obeke, Bailey et al., 2000).
5.3 Repackaging of light-sensitive medicines
Three drug products (tablets) have been evaluated in terms of their stability to light when
repackaged in various ‘bank bags’. Frusemide and chlorpromazine are known to be light
sensitive (Bundgaard, Nørgaard et al., 1988; Chagonda & Millership, 1989), while
pyrazinamide, exhibits good stability and is frequently repackaged into ‘bank bags’ in
developing countries for the treatment of patients with tuberculosis.
5.3.1 Frusemide and chlorpromazine
Frusemide tablets placed in a white opaque polyvinyl bag, the original blister (red) packing
and in a white opaque securitainer were exposed to window-filtered sunlight under
ambient temperature (25-40 ºC) conditions for 10 days (Soneman, 1995). Both the appearance
of the tablets and the drug content (using a validated HPLC method) was monitored. In all
cases discoloration of the tablets, similar to that observed on repackaging of these tablets
into a DAA of these tablets was noted. The percentage decrease in the frusemide content
was 14.49%, 12.73% and 21.27% respectively, with further investigation revealing that
temperature played a significant role in accelerating the photodegradation of the
repackaged frusemide. Recommendations were that patients be counselled on the storage of
repackaged frusemide tablets. Chlorpromazine similarly exposed to window filtered
sunlight under ambient conditions in a white opaque polyvinyl bag, discolored, with only
76% of the drug remaining after the exposure period of 1 month (Jacobsen, 1997). For
chlorpromazine it was recommended that in addition to counseling on storage of tablets to
be protected from light, that tablets would be repackaged bi-monthly.
5.3.2 Pyrazinamide
Since pyrazinamide is commonly repackaged into ‘bank bags’, the effect of exposure to
window-filtered sunlight for 3 days in both a ‘yellow bag’ commonly used in clinical
practice and a ‘brown bag’ was investigated. For both bags tested, photodegradation of
pyrazinamide was noted with the extent of degradation dependant both on the time of
exposure and the ‘type’ of bag. Results indicated that pyrazinamide was most stable in the
‘brown bag’, with 95% of the drug remaining while in the ‘yellow bag’ 8% of the drug
degraded. Although the protection offered by the ‘brown bag’ was superior, its use was
limited in practice due to lack of aesthetic appeal and patient acceptance (Defferary, 1993).
www.intechopen.com
240
Quality Assurance and Management
5.4 Repackaging moisture-sensitive medicines
Some moisture sensitive drugs, because of their hygroscopicity absorb moisture resulting in
tablets becoming unusable, due to loss of physical form. However there are instances where
the absorption of moisture by drugs may cause a polymorphic transition and as result
altered drug dissolution and bioavailability, which has the potential to seriously
compromise the quality of the drug product.
5.4.1 Carbamazepine
The antiepileptic drug carbamazepine has the ability to lose its effectiveness when exposed
to moisture due to a transformation from the anhydrous form to the dihydrate, which
although thermodynamically stable is less soluble and thus less bioavailable (al-Zein, Riad
et al., 1999). A study investigated the effect of repackaging of carbamazepine tablets into
white opaque ‘bank bags’ stored under ambient (25ºC; 60% RH), accelerated (40ºC; 75% RH)
and light (window-filtered sunlight) conditions for 30 days (Maharaj, 1997). Results from
this study however confirmed both the chemical and physical stability of the repackaged
carbamazepine tablets, under all storage conditions and thus the integrity of the ‘bank bag’.
6. Conclusion
This chapter highlights that despite the rigor of the requirements for the pharmaceutical
industry to provide quality medicines, there are a number of factors which have the ability
to contribute to the patient receiving a medicine, which is not of an appropriate quality. This
research confirms the role of health professionals especially pharmacists, because of their
specialist knowledge in medicines of being able to contribute substantially to ensuring the
quality of medicines for patients. It also raises the question as to whether we should be
looking more closely at not only undertaking more research independently into in-use drug
stability, but adding to the requirements for in-use stability testing to be undertaken on
medicines by the pharmaceutical industry.
7. Acknowledgment
The authors wish to acknowledge James Cook University, Griffith University and Dr Sherryl
Robertson, Mrs Martina Mylrea and Ms Victoria Llewelyn.
8. References
al-Zein, H., Riad, L. E. & Abd-Elbary, A. (1999). Effect of packaging and storage on the
stability of carbamazepine tablets. Drug Dev Ind Pharm Vol.25, No.2, pp. 223-227
Allen, L. V. J. (2003). Allen's compounded formulations: the complete US pharmacist collection,
Washington DC, American Pharmaceutical Association
AMH (2006). Australian medicines handbook. Drug Choice Companion: Aged Care, 2nd ed, ISBN
9780980579031, Adelaide, Australian Medicines Handbook Pty Ltd
Andrisano, V., Gotti, R., Leoni, A. & Cavrini, V. (1999). Photodegradation studies on
Atenolol by liquid chromatography. Journal of Pharmaceutical and Biomedical Analysis
Vol.21, No.4, pp. 851-857
www.intechopen.com
Quality Assurance of Medicines in Practice
241
Annemans, L., Wittrup-Jensen, K. & Bueno, H. (2010). A review of international
pharmacoeconomic models assessing the use of aspirin in primary prevention.
Journal of Medical Economics Vol.13, No.3, pp. 418-427
APAC (2002). Australian Pharmaceutical Advisory Council. Guidelines for medication management
in residential aged care facilities, 3rd ed, ISBN 0-642-82113-5, Canberra,
Commonwealth of Australia
Aryal, S. & Skalko-Basnet, N. (2008). Stability of amlodipine besylate and atenolol in multicomponent tablets of mono-layer and bi-layer types. Acta Pharmaceutica Vol.58,
No.3, pp. 299-308
Aulton, M. E. (2007). Aulton's Pharmaceutics. The Design and Manufacture of Medicines, ISBN
978-0-443-10108-3, Edinburgh, Churchill Livingstone
Australian_Government (2010). The Fifth Community Pharmacy Agreement between the
Commonwealth Government and the Pharmacy Guild of Australia. 7 July 2011,
Available from
http://www.5cpa.com.au/iwovresources/documents/The_Guild/PDFs/Other/Fifth%20Community%20Pharmac
y%20Agreement.pdf
Baertschi, S. W., Alsante, K. M. & Tonnesen, H. H. (2010). A critical assessment of the ICH
guideline on photostability testing of new drug substances and products (Q1B):
Recommendation for revision. Journal of Pharmaceutical Sciences Vol.99, No.7, pp.
2934-2940
Ballard, D. (1996). Reminder of danger from chewing extended-release products. American
Journal of Health-System Pharmacy Vol.53, No.16, pp. 1962, 1964
Bowen, L., Mangan, M., Haywood, A. & Glass, B. D. (2007). Stability of frusemide tablets
repackaged in Dose Administration Aids. Journal of Pharmacy Practice and Research
Vol.37, No.3, pp. 178-181
Bundgaard, H., Nørgaard, T. & Nielsen, N. M. (1988). Photodegradation and hydrolysis of
furosemide and furosemide esters in aqueous solutions. International Journal of
Pharmaceutics Vol.42, No.1, pp. 217-224
Chagonda, L. F. & Millership, J. S. (1989). The determination of chlorpromazine, related
impurities and degradation products in pharmaceutical dosage forms. Journal of
Pharmaceutical and Biomedical Analysis Vol.7, No.3, pp. 271-278
Chan, K., Swinden, J. & Donyai, P. (2007). Pilot study of the short-term physico-chemical
stability of atenolol tablets stored in a multi-compartment compliance aid. European
Journal of Hospital Pharmacy Science Vol.13, No.3, pp. 60-66
Church, C. & Smith, J. (2006). How stable are medicines moved from original packs into
compliance aids? The Pharmaceutical Journal Vol.276, pp. 75-81
Defferary, L. A. (1993). A stability study of pyrazinamide solid dosage forms. Port Elizabeth,
South Africa, University of Port Elizabeth. Honours Thesis (BPharm).
Giam, J. A. & McLachlan, A. J. (2008). Extemporaneous product use in paediatric patients: A
systematic review. International Journal of Pharmacy Practice Vol.16, No.1, pp. 3-10
Glass, B., Mangan, M. & Haywood, A. (2009). Prochlorperazine tablets repackaged into dose
administration aids: can the patient be assured of quality? Journal of Clinical
Pharmacy and Therapeutics Vol.34, No.2, pp. 161-169
www.intechopen.com
242
Quality Assurance and Management
Glass, B. D. & Haywood, A. (2006). Stability considerations in liquid dosage forms
extemporaneously prepared from commercially available products. Journal of
Pharmacy and Pharmaceutical Sciences Vol.9, No.3, pp. 398-426
Glass, B. D., Haywood, A., Llewelyn, V. & Mangan, M. (2009). Compliance aids and
medicine stability: new evidence of quality assurance. Current Drug Safety Vol.4,
No.1, pp. 74-78
Haywood, A. & Glass, B. D. (2009). Dosage form modification for the elderly. Australian
Pharmacist Vol.28, No.11, pp. 960-964
Haywood, A. & Glass, B. D. (2010). Paediatric mixtures. Australian Pharmacist Vol.29, No.4,
pp. 316-330
Haywood, A., Llewelyn, V., Robertson, S., Mylrea, M. & Glass, B. (2011). Dose
administration aids: Pharmacists’ role in improving patient care. Australasian
Medical Journal Vol.4, No.4, pp. 183-189
Haywood, A., Mangan, M. & Glass, B. D. (2006). Stability implications of repackaging
paracetamol tablets into Dose Administration Aids. Journal of Pharmacy Practice and
Research Vol.36, No.1, pp. 21-24
Haywood, A., Mangan, M., Grant, G. & Glass, B. D. (2005). Extemporaneous Isoniazid
mixture: stability implications. Journal of Pharmacy Practice and Research Vol.35,
No.3, pp. 181-182
ICH (1996). ICH Harmonised Tripartite Guideline. Stability Testing: Photostability testing of
new drug substances and products Q1B: ICH Steering Committee, 7 July 2011,
Available from
http://www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/Qua
lity/Q1B/Step4/Q1B_Guideline.pdf
ICH (2003). ICH Harmonised Tripartite Guideline. Stability Testing of New Drug
Substances and Products Q1A(R2): ICH Steering Committee. 7 July 2011, Available
from
http://www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/Qua
lity/Q1A_R2/Step4/Q1A_R2__Guideline.pdf
Jacobsen, L. J. (1997). A study into the effect of packaging on the stability of chlorpromazine
tablets. Grahamstown, South Africa, Rhodes University. Honours Thesis (BPharm).
Kawamura, O., Easterling, C., Aslam, M., Rittmann, T., Hofmann, C. & Shaker, R. (2004).
Laryngo-upper esophageal sphincter contractile reflex in humans deteriorates with
age. Gastroenterology Vol.127, No.1, pp. 57-64
Kelly, K. & Vaida, A. J. (2003). Warning! - Repackaged substances may easily be confused.
Pharmacy Times Vol.69, No.5, pp. 30-32
Kohara, T., Koyama, T., Fujimura, M., Tanaka, H., Maeda, J., Fujimoto, T., Yamamoto, I. &
Arita, M. (2002). Y-931, a novel atypical antipsychotic drug, is less sensitive to
oxidative phenomena. Chemical and Pharmaceutical Bulletin (Tokyo) Vol.50, No.6, pp.
818-821
Lagrange, F. (2010). Current perspectives on the repackaging and stability of solid oral
doses. Annales Pharmacetiques Francaises Vol.68, No.6, pp. 332-358
Lee, J. K., Grace, K. A. & Taylor, A. J. (2006). Effect of a pharmacy care program on
medication adherence and persistence, blood pressure, and low-density lipoprotein
cholesterol: a randomized controlled trial. The Journal of the American Medical
Association Vol.296, No.21, pp. 2563-2571
www.intechopen.com
Quality Assurance of Medicines in Practice
243
Leon Villar, J., Iranzo Fernandez, M. D., Ventura Lopez, M., Najera Perez, M. D. & Victorio
Garcia, L. (2001). Línea de Control de Calidad en el reenvasado de medicamentos.
Bases metodológicas. Diseño. Utilidad. Farmacia Hospitalaria Vol.25, No.1, pp. 31-37
Llewelyn, V. K., Mangan, M. F. & Glass, B. D. (2010). Stability of sodium valproate tablets
repackaged into dose administration aids. Journal of Pharmacy and Pharmacology
Vol.62, No.7, pp. 838-843
Maharaj, S. (1997). Carbamazepine tablets: An in-use stability evaluation. Grahamstown,
South Africa, Rhodes University. Honours Thesis (BPharm).
Marriott, J. L. & Nation, R. L. (2002). Splitting tablets. Australian Prescriber Vol.25, No.6, pp.
133-135
Mitchell, J. F. (2011). Oral dosage forms that should not be crushed. Institute for Safe
Medication Practices, 7 July 2011, Available from
www.ismp.org/tools/donotcrush.pdf
Moore, D. E. & Tamat, S. R. (1980). Photosensitization by drugs: photolysis of some chlorinecontaining drugs. Journal of Pharmacy and Pharmacology Vol.32, No.3, pp. 172-177
Morris, H. (2005). Administering drugs to patients with swallowing difficulties. Nursing
Times Vol.101, No.39, pp. 28-30
Nahata, M. C. & Allen, L. V., Jr. (2008). Extemporaneous drug formulations. Clinical
Therapeutics Vol.30, No.11, pp. 2112-2119
Nahata, M. C. & Morosco, R. S. (2003). Stability of tiagabine in two oral liquid vehicles.
American Journal of Health-System Pharmacy Vol.60, No.1, pp. 75-77
Nahata, M. C., Pai, V. B. & Hipple, T. F. (2004). Pediatric drug formulations. 5th ed., Cincinnati
Nejmeh, M. & Pilpel, N. (1978). The effect of the photodecomposition of chlorpromazine on
lecithin monolayers. Journal of Pharmacy and Pharmacology Vol.30, No.12, pp. 748-753
Nunney, J. M. & Rayner, D. K. T. (2001). How are multi-compartment compliance aids used
in primary care? The Pharmaceutical Journal Vol.267, pp. 784-789
Obeke, C. C., Bailey, L., Medwick, T. & Grady, L. T. (2000). Revised USP standards for
product dating, packaging, and temperature monitoring. American Journal of HealthSystem Pharmacy Vol.57, No.15, pp. 1441-1445
Perks, S., Robertson, S., Haywood, A. & Glass, B. D. (2011). Clozapine Repackaged into Dose
Administration Aids: A Common Practice in Australian Hospitals. International
Journal of Pharmacy Practicepp. (in press)
Prankerd, R. J. (2009). Compounded products - Stability studies in Hospital Pharmacy
departments. Journal of Pharmacy Practice and Research Vol.39, No.1, pp. 5-7
PSA (2007). Pharmaceutical Society of Australia. Guidelines and standards for pharmacists.
Dose Administration Aids Service. 7 July 2011, Available from
http://www.psa.org.au/site.php?id=2065
PSA (2010). Professional Practice Standards. Version 4. Standard 7: Dose Administration Aids
Service, Pharmaceutical Society of Australia
RPSGB (2003). Medicines, Ethics, and Practice: A Guide for Pharmacists, Volume 27, ISSN 09554254, London, Royal Pharmaceutical Society of Great Britain
Schier, J. G., Howland, M. A., Hoffman, R. S. & Nelson, L. S. (2003). Fatality from
administration of labetalol and crushed extended-release nifedipine. The Annals of
Pharmacotherapy Vol.37, No.10, pp. 1420-1423
www.intechopen.com
244
Quality Assurance and Management
Simmons, D., Upjohn, M. & Gamble, G. D. (2000). Can medication packaging improve
glycemic control and blood pressure in type 2 diabetes? Results from a randomized
controlled trial. Diabetes Care Vol.23, No.2, pp. 153-156
Soneman, L. J. (1995). Evaluation of the relative light stability of furosemide when packed in
blister packs, securitainers and approved bank bags. Grahamstown, South Africa,
Rhodes University. Honours Thesis (BPharm).
TGA (2011). Therapeutic Goods Administration. Colourings Permitted in Medicines for Oral
Use. 7 July 2011, Available from http://www.tga.gov.au/industry/cm-colouringsoral-use.htm
Trissel, L. A. (2009). Trissel's Stability of Compounded Formulations. 4th ed, Washington, DC,
American Pharmacists Association
USP (2010). US Pharmacopeial Convention Inc. US Pharmacopeia 33 - National formulary 28
<681> Repackaging into single-unit containers and unit-dose containers for
nonsterile solid and liquid dosage forms.
Walker, R. (1992). Stability of medicinal products in compliance devices. The Pharmaceutical
Journal Vol.25, pp. 124-126
Ware, G. J., Holford, N. H., Davison, J. G. & Harris, R. G. (1994). Unit-of-issue medicine
administration: time and cost-benefits in a geriatric unit. Australian Journal of
Hospital Pharmacy Vol.24, No.4, pp. 329-332
White, R. & Bradnam, V. (2007). Handbook of Drug Administration via Enteral Feeding Tubes,
ISBN 978-0-85369-928-6, London, Pharmaceutical Press
www.intechopen.com
Quality Assurance and Management
Edited by Prof. Mehmet Savsar
ISBN 978-953-51-0378-3
Hard cover, 424 pages
Publisher InTech
Published online 23, March, 2012
Published in print edition March, 2012
The purpose of this book is to present new concepts, state-of-the-art techniques and advances in quality
related research. Novel ideas and current developments in the field of quality assurance and related topics are
presented in different chapters, which are organized according to application areas. Initial chapters present
basic ideas and historical perspectives on quality, while subsequent chapters present quality assurance
applications in education, healthcare, medicine, software development, service industry, and other technical
areas. This book is a valuable contribution to the literature in the field of quality assurance and quality
management. The primary target audience for the book includes students, researchers, quality engineers,
production and process managers, and professionals who are interested in quality assurance and related
areas.
How to reference
In order to correctly reference this scholarly work, feel free to copy and paste the following:
Beverley Glass and Alison Haywood (2012). Quality Assurance of Medicines in Practice, Quality Assurance
and Management, Prof. Mehmet Savsar (Ed.), ISBN: 978-953-51-0378-3, InTech, Available from:
http://www.intechopen.com/books/quality-assurance-and-management/quality-assurance-of-medicines-inpractice
InTech Europe
InTech China
University Campus STeP Ri
Slavka Krautzeka 83/A
51000 Rijeka, Croatia
Phone: +385 (51) 770 447
Fax: +385 (51) 686 166
www.intechopen.com
Unit 405, Office Block, Hotel Equatorial Shanghai
No.65, Yan An Road (West), Shanghai, 200040, China
Phone: +86-21-62489820
Fax: +86-21-62489821