Browsing by Author "Nebsen, Marianne"

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Quantitative determination of citalopram hydrobromide by spectro-photometry and chemometry in presence of its degradation products and additivesin pharmaceutical preparation
(Analytical Chemistry: An Indian Journal, 2016) M. El-Maraghy, Christine; M. Amer, Sawsan; Salem, Hesham; Nebsen, Marianne
Simple, accurate, sensitive and validated UV stability-indicating spectro- photometric and chemometric methods were developed for determination of Citalopram Hydrobromide (CT) in presence of its alkaline, oxidative degradation products and in its pharmaceutical preparation. Method (A) is a successive derivative ratio spectrophotometricone, which depends on the successive derivative ofratio spectra in two steps and measuring Citalopram Hydrobromide at 277nm and 293nm. Method (B) is mean centering of ratio spectra which dependson using the mean centered ratio spectra in two successive steps and measuring the mean centeredvalues of the second ratio spectra at 237nm and method (C) used two chemometric techniques ; principal component regression(PCR) and partial least-squares (PLS). The proposed methods werechecked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceuticalformulation containing Citalopram Hydrobromide. The proposed methods were vali- dated according to the ICH guidelines. The obtained results were statisti- cally compared with those obtained froma compendial HPLC method,showing no significant difference with respect to accuracy and precision.
Stability Indicating Spectrophotometric and Chemometric Methods for Determination of Aripiprazole in Presence of its Degradation Products, A Comparative Study
(Taylor & Francis, 2019) M. El-Maraghy, Christine; Salem, Hesham; M. Amer, Sawsan; Nebsen, Marianne
Simple, accurate, selective and validated stability indicating UV spectrophotometric univariate and multivariate methods were developed for determination of Aripiprazole in presence of its alkaline and oxidative degradation products. The developed univariate methods; derivative ratio spectra-zero crossing, successive derivatives of ratio spectra and mean centering of ratio spectra. The first one used the amplitude of the first derivative ratio signals at 303.0 nm, the second method depended on the successive derivative of ratio spectra in two steps and measuring the absorbance of Aripiprazole at 281.0 nm and the third one measured the mean centered values oat 294.0 nm. Two chemometric multivariate methods were applied; principal component regression (PCR) and partial least-squares regression (PLS). The selectivity of the proposed methods was confirmed using laboratory-prepared mixtures. The obtained results were statistically compared with those obtained with the manufacturer HPLC method, showing no significant difference with in accuracy and precision. These methods could be applied as stability indicating methods for the determination of Aripiprazole in presence of its degradation products, in bulk powder or in pharmaceutical formulations.
Validated HPLC Method for Simultaneous Determination of Aripiprazole and Co-Administered Clonazepam in Spiked Human Plasma
(Journal of Pharmaceutical and Applied Chemistry An International Journal, 2017) M. El-Maraghy, Christine; Salem, Hesham; M. Amer, Sawsan; Nebsen, Marianne
A sensitive and selective high performance liquid chromatographic method was developed and validated for the simultaneous quantification of Aripiprazole and co-administered Clonazepam in spiked human plasma. Aripiprazole, Clonazepam and the internal standard Citalopram were extracted from plasma and analyzed on a reversed-phase C18 column using a mobile phase consisting of acetonitrile and 0.05M potassium dihydrogen orthophosphate (pH= 3.6) in a ratio of (40: 60, v/v). The ultraviolet (UV) detection was at 220 nm. The method was linear over concentration range (20- 1000 ng mL-1 ) for both drugs. The method is very simple and allows obtaining a very good recovery of the analytes.