Journal of Liquid Chromatography & Related Technologies, 2007
A High performance liquid chromatographic (HPLC) method is presented for the determination of ace... more A High performance liquid chromatographic (HPLC) method is presented for the determination of acenocoumarol and its thermal degradation product using a reverse phase C18 column at ambient temperature with the mobile phase consisting of water, and the pH adjusted to 3.0 using phosphoric acid:acetonitrile (50∶50). Quantitation was achieved with UV detection at 280 nm based on peak area. The method was
Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compa... more Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of lipoic acid with some currently employed cosmetic excipients. In the first phase of the study DSC was used as a tool to detect any interaction. Based on the DSC results alone, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 °C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The stability of ascorbyl palmitate, sodium ascorbyl phosphate and magnesium ascorbyl phosphate i... more The stability of ascorbyl palmitate, sodium ascorbyl phosphate and magnesium ascorbyl phosphate in topical formulations was investigated by direct reverse phase high performance liquid chromatography after sample dilution with a suitable buffer – organic solvent mixture. Ascorbyl palmitate, sodium ascorbyl phosphate and magnesium ascorbyl phosphate are derivatives of ascorbic acid which differ in hydrolipophilic properties. They are widely used in cosmetic and pharmaceutical preparations. According to the results, ascorbyl esters showed significant differences: sodium ascorbyl phosphate and magnesium ascorbyl phosphate are more stable derivatives of vitamin C than ascorbyl palmitate and may be easily used in cosmetic products.On recherche la stabilité du palmitate d’ ascorbyl et phosphate de magnésium dans des formulations topiques par RP-HPLC directe après dilution de l’échantillon avec une mélange approprié tampon-dissolvant organique. Les propriétés hydro-lipophiles du palmitate d’ascorbyl, du phosphate d’ascorbyl et sodium et du phosphate d’ascorbyl et magnésium, dérivés du acide ascorbique, sont différentes. Ils sont utilisés vastement dans des préparations cosmétiques et pharmaceutiques. Selon les résultats, ils montrent différences significatives: le phosphate d’ascorbyl et sodium et le phosphate d’ascorbyl et magnésium, sont les dérivés plus stables de la vitamine C, et peuvent être utilisés facilement dans des produits cosmétiques.
Journal of Liquid Chromatography & Related Technologies, 2003
The determination of sibutramine hydrochloride in the presence of its oxidatively‐induced degrada... more The determination of sibutramine hydrochloride in the presence of its oxidatively‐induced degradation products by reversed‐phase HPLC is described. The method was validated as stability‐indicating by forced decomposition of sibutramine hydrochloride in acid, base, water, oxidative, thermal, and photochemical media. The chromatographic conditions employed a reversed‐phase C18 column (Microsorb‐MV™ 100 A, 5 µm, 25 cm × 4.6 mm). The mobile phase consisted of methanol:water : triethylamine (80:20:0.3)
Journal of Liquid Chromatography & Related Technologies, 2006
A simple and precise reversed-phase high performance liquid chromatography (HPLC) method for the ... more A simple and precise reversed-phase high performance liquid chromatography (HPLC) method for the determination of hydrochlorothiazide (HCT) in human plasma was developed and validated.
A simple and accurate high-performance liquid chromatographic (HPLC) method was developed to dete... more A simple and accurate high-performance liquid chromatographic (HPLC) method was developed to determine Celecoxib in capsule formulations. The drug was chromatographed on a reversed-phase C-18 column. Eluents were monitored at a wavelength of 251 nm using a mixture (85:15) of methanol and water. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The method was statistically validated for linearity, accuracy, precision, and selectivity. Due to its simplicity and accuracy, we believe that the method will be useful for routine quality control analysis.
Journal of Liquid Chromatography & Related Technologies, 2009
A high performance liquid chromatographic (HPLC) method is presented for the determination of mep... more A high performance liquid chromatographic (HPLC) method is presented for the determination of meprednisone in the presence of its degradation products using a reverse phase C18 column at ambient temperature with mobile phase consisting of acetonitrile:0.04 M dibasic sodium phosphate, pH adjusted to 7.0 (45:65, v/v). The flow rate was 1.3 mL/min. Quantitation was achieved with UV detection at 245 nm based on
Journal of Liquid Chromatography & Related Technologies, 2005
A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed a... more A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation, chromatographic separation of ciprofloxacin in plasma was achieved at 35 8C with a C18 column and acetonitrile Á/phosphate mixture, pH 3, as mobile phase. Quantitative determination was performed by fluorimetry after excitation at 278 nm. The method was specific and validated with a limit of quantification of 41 ng/ml. The intra-and inter-day coefficients of variation were between 0.5 and 6.6% and accuracy between (/2.02 and 7.04%. Ciprofloxacin was stable in plasma for 40 days at (/20 8C and after three freezing-thawing cycles. The method has been applied in a bioequivalence study of two formulation of 500 mg ciprofloxacin. #
Silybine (SBN), isosilybine (ISBN), silycristine (SCN), silydianine (SDN), and taxifoline (TXF) a... more Silybine (SBN), isosilybine (ISBN), silycristine (SCN), silydianine (SDN), and taxifoline (TXF) are the main active flavonoids commonly found in the dried fruits of Silybum marianum, Gaertner (Compositae). Concentrations of these compounds, except TXF, are usually expressed together as silymarin content. This paper describes a simple dissolution test developed to estimate silymarin (Sl) in pharmaceutical formulations. Five commercial products were tested using this new method (including tablets, sugar tablets, and capsules): two from Argentina, one from Brazil, one from Spain, and one from Italy. Results demonstrated that, provided the dosage form disintegrates, amounts dissolved range from 50 to 90% of the labeled value. Products were analyzed by high performance liquid chromatography (HPLC) and UV spectrophotometry.
Journal of Liquid Chromatography & Related Technologies, 2002
A simple high performance liquid chromatographic method was developed for simultaneous determinat... more A simple high performance liquid chromatographic method was developed for simultaneous determination of finasteride and its degradation products. HPLC analysis was carried out using a C18 column and methanol:water (70 : 30) as the mobile phase. Detection was carried out at 210 nm using a flow rate of 1.0 mL per min. Finasteride was eluted at 6 min. Standard deviation values were below 2%.The method was validated as stability-indicating by forced decomposition of finasteride using acid, base, hydrogen peroxide, heat, and light. Chromatograms showed good resolution, sensitivity, and no interference of degradation products. The response was linear over the concentration range of 50 to 800 µg/mL, with correlation coefficients of variation greater than 0.9995. Recovery studies gave results between 100 to 103%.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ABSTRACT The design, synthesis, binding affinities for rabbit uterus estrogen receptors and in vi... more ABSTRACT The design, synthesis, binding affinities for rabbit uterus estrogen receptors and in vivo action of two trisubstituted dihydrobenzo[a]carbazoles are reported. Relative binding affinities were similar to tamoxifen. In vivo studies in rats bearing NMU-induced mammary tumours indicate that tamoxifen (200 μg sc daily) led to 51.6% tumour regression, ovariectomy to 54.4%, and derivatives 6 and 7 (200 μg sc daily) to 50.0 and 54.8%, respectively. These experiments demonstrated that derivatives 6 and 7 are as effective as tamoxifen in the model studied.
The effectiveness of any cosmetic product containing a functional ingredient is determined by the... more The effectiveness of any cosmetic product containing a functional ingredient is determined by the skin delivery of the active molecule, which is influenced by the type of carrier and the molecule itself. Furthermore, the functional ingredient should be stable in the formulation.
Journal of Liquid Chromatography & Related Technologies, 2005
A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed a... more A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation, chromatographic separation of ciprofloxacin in plasma was achieved at 35 8C with a C18 column and acetonitrile Á/phosphate mixture, pH 3, as mobile phase. Quantitative determination was performed by fluorimetry after excitation at 278 nm. The method was specific and validated with a limit of quantification of 41 ng/ml. The intra-and inter-day coefficients of variation were between 0.5 and 6.6% and accuracy between (/2.02 and 7.04%. Ciprofloxacin was stable in plasma for 40 days at (/20 8C and after three freezing-thawing cycles. The method has been applied in a bioequivalence study of two formulation of 500 mg ciprofloxacin. #
Journal of Experimental Therapeutics and Oncology, 2002
of estradiol, as well as the necessary presence of the aminoalkyl chain on the annular N atom. Ho... more of estradiol, as well as the necessary presence of the aminoalkyl chain on the annular N atom. However, the effect of alkyl chain enlargement in the nitrogen substituent on the biological activity of those drugs is as yet unclear.
Journal of Liquid Chromatography & Related Technologies, 2007
A High performance liquid chromatographic (HPLC) method is presented for the determination of ace... more A High performance liquid chromatographic (HPLC) method is presented for the determination of acenocoumarol and its thermal degradation product using a reverse phase C18 column at ambient temperature with the mobile phase consisting of water, and the pH adjusted to 3.0 using phosphoric acid:acetonitrile (50∶50). Quantitation was achieved with UV detection at 280 nm based on peak area. The method was
Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compa... more Differential scanning calorimetry (DSC) was used as a screening technique for assessing the compatibility of lipoic acid with some currently employed cosmetic excipients. In the first phase of the study DSC was used as a tool to detect any interaction. Based on the DSC results alone, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butylated hydroxytoluene, non ionic self emulsifying wax, propylene glycol and acetylated lanolin were found to exhibit interaction with lipoic acid. Stressed binary mixtures (stored at 50 °C for 1 week) of lipoic acid and excipients were evaluated by HPLC. Binary mixtures were evaluated by IR spectroscopy.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The stability of ascorbyl palmitate, sodium ascorbyl phosphate and magnesium ascorbyl phosphate i... more The stability of ascorbyl palmitate, sodium ascorbyl phosphate and magnesium ascorbyl phosphate in topical formulations was investigated by direct reverse phase high performance liquid chromatography after sample dilution with a suitable buffer – organic solvent mixture. Ascorbyl palmitate, sodium ascorbyl phosphate and magnesium ascorbyl phosphate are derivatives of ascorbic acid which differ in hydrolipophilic properties. They are widely used in cosmetic and pharmaceutical preparations. According to the results, ascorbyl esters showed significant differences: sodium ascorbyl phosphate and magnesium ascorbyl phosphate are more stable derivatives of vitamin C than ascorbyl palmitate and may be easily used in cosmetic products.On recherche la stabilité du palmitate d’ ascorbyl et phosphate de magnésium dans des formulations topiques par RP-HPLC directe après dilution de l’échantillon avec une mélange approprié tampon-dissolvant organique. Les propriétés hydro-lipophiles du palmitate d’ascorbyl, du phosphate d’ascorbyl et sodium et du phosphate d’ascorbyl et magnésium, dérivés du acide ascorbique, sont différentes. Ils sont utilisés vastement dans des préparations cosmétiques et pharmaceutiques. Selon les résultats, ils montrent différences significatives: le phosphate d’ascorbyl et sodium et le phosphate d’ascorbyl et magnésium, sont les dérivés plus stables de la vitamine C, et peuvent être utilisés facilement dans des produits cosmétiques.
Journal of Liquid Chromatography & Related Technologies, 2003
The determination of sibutramine hydrochloride in the presence of its oxidatively‐induced degrada... more The determination of sibutramine hydrochloride in the presence of its oxidatively‐induced degradation products by reversed‐phase HPLC is described. The method was validated as stability‐indicating by forced decomposition of sibutramine hydrochloride in acid, base, water, oxidative, thermal, and photochemical media. The chromatographic conditions employed a reversed‐phase C18 column (Microsorb‐MV™ 100 A, 5 µm, 25 cm × 4.6 mm). The mobile phase consisted of methanol:water : triethylamine (80:20:0.3)
Journal of Liquid Chromatography & Related Technologies, 2006
A simple and precise reversed-phase high performance liquid chromatography (HPLC) method for the ... more A simple and precise reversed-phase high performance liquid chromatography (HPLC) method for the determination of hydrochlorothiazide (HCT) in human plasma was developed and validated.
A simple and accurate high-performance liquid chromatographic (HPLC) method was developed to dete... more A simple and accurate high-performance liquid chromatographic (HPLC) method was developed to determine Celecoxib in capsule formulations. The drug was chromatographed on a reversed-phase C-18 column. Eluents were monitored at a wavelength of 251 nm using a mixture (85:15) of methanol and water. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The method was statistically validated for linearity, accuracy, precision, and selectivity. Due to its simplicity and accuracy, we believe that the method will be useful for routine quality control analysis.
Journal of Liquid Chromatography & Related Technologies, 2009
A high performance liquid chromatographic (HPLC) method is presented for the determination of mep... more A high performance liquid chromatographic (HPLC) method is presented for the determination of meprednisone in the presence of its degradation products using a reverse phase C18 column at ambient temperature with mobile phase consisting of acetonitrile:0.04 M dibasic sodium phosphate, pH adjusted to 7.0 (45:65, v/v). The flow rate was 1.3 mL/min. Quantitation was achieved with UV detection at 245 nm based on
Journal of Liquid Chromatography & Related Technologies, 2005
A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed a... more A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation, chromatographic separation of ciprofloxacin in plasma was achieved at 35 8C with a C18 column and acetonitrile Á/phosphate mixture, pH 3, as mobile phase. Quantitative determination was performed by fluorimetry after excitation at 278 nm. The method was specific and validated with a limit of quantification of 41 ng/ml. The intra-and inter-day coefficients of variation were between 0.5 and 6.6% and accuracy between (/2.02 and 7.04%. Ciprofloxacin was stable in plasma for 40 days at (/20 8C and after three freezing-thawing cycles. The method has been applied in a bioequivalence study of two formulation of 500 mg ciprofloxacin. #
Silybine (SBN), isosilybine (ISBN), silycristine (SCN), silydianine (SDN), and taxifoline (TXF) a... more Silybine (SBN), isosilybine (ISBN), silycristine (SCN), silydianine (SDN), and taxifoline (TXF) are the main active flavonoids commonly found in the dried fruits of Silybum marianum, Gaertner (Compositae). Concentrations of these compounds, except TXF, are usually expressed together as silymarin content. This paper describes a simple dissolution test developed to estimate silymarin (Sl) in pharmaceutical formulations. Five commercial products were tested using this new method (including tablets, sugar tablets, and capsules): two from Argentina, one from Brazil, one from Spain, and one from Italy. Results demonstrated that, provided the dosage form disintegrates, amounts dissolved range from 50 to 90% of the labeled value. Products were analyzed by high performance liquid chromatography (HPLC) and UV spectrophotometry.
Journal of Liquid Chromatography & Related Technologies, 2002
A simple high performance liquid chromatographic method was developed for simultaneous determinat... more A simple high performance liquid chromatographic method was developed for simultaneous determination of finasteride and its degradation products. HPLC analysis was carried out using a C18 column and methanol:water (70 : 30) as the mobile phase. Detection was carried out at 210 nm using a flow rate of 1.0 mL per min. Finasteride was eluted at 6 min. Standard deviation values were below 2%.The method was validated as stability-indicating by forced decomposition of finasteride using acid, base, hydrogen peroxide, heat, and light. Chromatograms showed good resolution, sensitivity, and no interference of degradation products. The response was linear over the concentration range of 50 to 800 µg/mL, with correlation coefficients of variation greater than 0.9995. Recovery studies gave results between 100 to 103%.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ABSTRACT The design, synthesis, binding affinities for rabbit uterus estrogen receptors and in vi... more ABSTRACT The design, synthesis, binding affinities for rabbit uterus estrogen receptors and in vivo action of two trisubstituted dihydrobenzo[a]carbazoles are reported. Relative binding affinities were similar to tamoxifen. In vivo studies in rats bearing NMU-induced mammary tumours indicate that tamoxifen (200 μg sc daily) led to 51.6% tumour regression, ovariectomy to 54.4%, and derivatives 6 and 7 (200 μg sc daily) to 50.0 and 54.8%, respectively. These experiments demonstrated that derivatives 6 and 7 are as effective as tamoxifen in the model studied.
The effectiveness of any cosmetic product containing a functional ingredient is determined by the... more The effectiveness of any cosmetic product containing a functional ingredient is determined by the skin delivery of the active molecule, which is influenced by the type of carrier and the molecule itself. Furthermore, the functional ingredient should be stable in the formulation.
Journal of Liquid Chromatography & Related Technologies, 2005
A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed a... more A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation, chromatographic separation of ciprofloxacin in plasma was achieved at 35 8C with a C18 column and acetonitrile Á/phosphate mixture, pH 3, as mobile phase. Quantitative determination was performed by fluorimetry after excitation at 278 nm. The method was specific and validated with a limit of quantification of 41 ng/ml. The intra-and inter-day coefficients of variation were between 0.5 and 6.6% and accuracy between (/2.02 and 7.04%. Ciprofloxacin was stable in plasma for 40 days at (/20 8C and after three freezing-thawing cycles. The method has been applied in a bioequivalence study of two formulation of 500 mg ciprofloxacin. #
Journal of Experimental Therapeutics and Oncology, 2002
of estradiol, as well as the necessary presence of the aminoalkyl chain on the annular N atom. Ho... more of estradiol, as well as the necessary presence of the aminoalkyl chain on the annular N atom. However, the effect of alkyl chain enlargement in the nitrogen substituent on the biological activity of those drugs is as yet unclear.
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Papers by Adriana Segall