Two new Spectrophotometric Approaches to the Simultaneous Determination of Ezetimibe and Atorvastatin Calcium

Two rapid, simple and sensitive spectrophotometric methods for the quantitative analysis of ezetimibe (EZB) and atorvastatin calcium (ATVC) in bulk powder and combined tablet form have been developed and validated. The first method is bivariate calibration and the second method is ratio subtraction in conjunction with second derivative (D )spectrophotometry. These methods are tested by analyzing synthetic binary mixtures of the above drugs and they are applied to commercial pharmaceutical preparation of the subjected drugs. Standard deviation is < 2 in the assay of raw materials and tablets. Methods are validated as per ICH guidelines and statistical comparison of the suggested methods with the reported spectrophotometric one using F and t tests showed no significant difference regarding both accuracy and precision.International Journal of Chemical Studie

Development and Validation of Spectrophotometric, Chemometric and HighPressure Liquid Chromatographic Methods for the Determination of Cefepime Hydrochloride In The Presence of Its Acid and Alkaline Degradation Products

In this study, stability-indicating methods for the determination of cefepime hydrochloride (CPM) were conducted by the application of spectrophotometry, chemometry and high-performance liquid chromatography (HPLC). Five different, accurate, sensitive and reproducible methods were applied for the simultaneous analysis of cefepime hydrochloride (CPM) in the presence of its acid and alkaline degradation products in their laboratory prepared mixtures and pharmaceutical preparations. The first method is based on derivative spectrophotometry. First derivative spectrophotometry was applied where CPM was determined at 279 and 312 nm in the presence of its alkaline degradation product and also second derivative spectrophotometry was applied where CPM was determined at 236 nm in the presence of its acid degradation product. The second method is based on the first derivative of ratio spectrophotometry (1DD) of CPM at 258 and 286 nm in the presence of its acid degradation product and at 251 and 285 nm in the presence of its alkaline degradation product. The third method is based on ratio subtraction spectrophotometry where the drug is determined at 236 nm in laboratory prepared mixtures of CPM with its acid or alkaline degradation product. The fourth method is the application of multivariate calibration models, namely, Principle Component Regression (PCR) and Partial Least Squares (PLS). The four proposed spectrophotometric methods permit the determination of CPM in the range of 3.0-30.0 μg/ml. The fifth method is an isocratic reversed-phase HPLC procedure, a Zorbax C18 column was used to separate CPM from its acid and alkaline degradation products using acetonitrile: water (20:80, v/v) as a mobile phase and detection at 254 nm. The suggested procedures were successfully applied for the analysis of CPM in bulk powder and in pharmaceutical preparations. The results obtained by the proposed methods were statistically comparable with those obtained by the official method. All the proposed methods were validated according to the International Conference on Harmonization (ICH) guidelines

Stability indicating methods for the determination of cefpodoxime proxetil in the presence of its acid and alkaline degradation products

Four different, accurate, sensitive and reproducible stability-indicating methods for the determination of cefpodoxime proxetil (CPD) in the presence of its acid and alkaline degradation products are presented. The first method is based on derivative spectrophotometry. Second derivative spectrophotometry was applied where CPD was determined at 261 nm in the presence of its acid degradation product and also third derivative spectrophotometry was applied where CPD was determined at 282 nm in the presence of its alkaline degradation product. The second method is based on the first derivative of ratio spectrophotometry ( 1 DD) of CPD at 215 nm and 255 nm in the presence of its acid degradation product and at 243 nm in the presence of its alkaline degradation product. The third method is ratio subtraction spectrophotometry where the drug is determined at 232 nm in laboratory prepared mixtures of CPD and its acid or alkaline degradation product. Calibration graphs were established for 4.0-40.0 μg/ml for CPD determination by the three spectrophotometric methods. The fourth method is an isocratic reversed -phase HPLC procedure, a Zorbax C column was used to separate CPD from its acid and alkaline degradation product using acetonitrile: water: triethylamine (60:40:1, v/v/v) as a mobile phase and detection at 232 nm. The suggested procedures were successfully applied for the analysis of CPD in bulk powder and in pharmaceutical preparations. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the official method

Stability indicating chemometric methods for the determination of two cephalosporin drugs by partial least squares and principle component regression multivariate calibration methods

In this study, Two multivariate calibration methods, including principal component regression (PCR) and partial least square (PLS), have been used for the determination of two cephalosporin drugs namely cefpodoxime and cefixime in the presence of their acidic and alkaline induced degradation products. Although the components show a large degree of spectral overlap, they have been determined simultaneously and rapidly requiring no separation step. The PCR and PLS techniques are useful chemometric approaches using UV spectral analysis due to the simultaneous inclusion of many spectral wavelengths instead of the single wavelength used in derivative spectrophotometry, thus a great improvement in the precision and predictive abilities of these multivariate calibrations is observed. Spectra of cefpodoxime and cefixime and their acidic and alkaline induced degradation products were recorded at several concentrations within their linear ranges and were used to compute the calibration mixture between wavelengths 200 and 400 nm at an interval of 1 nm in water. PLS and PCR were used for chemometric analysis of data and the parameters of the chemometric procedures were optimized. A calibration set was constructed for the mixture and the best model was used for the prediction of the concentration of the selected drug. The proposed procedures were successfully applied for the determination of cefpodoxime and cefixime in laboratory‐prepared mixtures and in pharmaceutical formulations, with no interference from excipients as indicated by the recovery study results. The validity of the proposed methods was assessed using the standard addition technique

Validated HPTLC and HPLC methods for determination of fluorometholone and sodium cromoglycate in presence of their impurities and degradation products; application to kinetic study and on rabbit aqueous humor

<p>Fluorometholone (FLM) and Sodium Cromoglycate (CMG) are co-formulated in ophthalmic preparation and showed marked instability under different conditions. Two specific, sensitive and precise stability-indicating chromatographic methods have been developed and validated for their determination in the presence of their degradation products and FLM impurity. Ten components were efficiently separated by them. The first method was HPTLC-spectrodensitometry, where the separation was achieved using silica gel 60 F₂₅₄ HPTLC plates and developing system of ethyl acetate: methanol (9:1, v/v). The second method was a reversed phase HPLC associated with kinetic study of the degradation process and was successfully applied for determination of the studied compounds in spiked rabbit aqueous humor. The mobile phase was acetonitrile: methanol: 0.05 M potassium dihydrogenphosphate (0.1% trimethylamine); pH 2.5, adjusted with orthophosphoric acid (20: 30: 50, by volume). In both methods, the separated components were detected at 240 nm and system suitability was checked. Good correlation was obtained in the range of 0.10–24.00 and 0.20–48.00 µg band⁻¹, for FLM and CMG by HPTLC. While for HPLC, the linearity ranges from 0.01–50.00 and 0.05–50.00 µg mL⁻¹ for both drugs. The methods were applied in pharmaceutical formulation, where they were compared to the reported method with no significant difference.</p

Simultaneous Determination Of Ezetimibe And Atorvastatin Calcium In Binary Mixture By Second Derivative (D 2 ) Spectrofluorimetric Method

A method for the simultaneous determination of ezetimibe (EZB) and atorvastatin calcium (ATVC) was developed, based on the measurement of their native fluorescence signals, by using second-derivative spectrofluorimetry to resolve the mixture. EZB was measured at λ 455.0 nm, and ATVC was measured at λ em = 394.0 nm. Instrumental parameters were optimized, and the emission spectra were recorded between 380.0 and 470.0 nm, at λ em = ex = 246.0 nm and excitation and emission slit widths of 10.0 nm. The calibration graphs were linear over the ranges of 200 – 900 ng/mL for both EZB and ATVC, with a mean percentage recovery of 99.64 ± 0.88 and 99.88 ± 0.61, respectively. Methods were validated according to ICH guidelines and successfully applied for analysis of bulk powder and pharmaceutical formulations. The results were statistically compared to a reported method and no significant difference was noticed regarding accuracy and precision.Australian Journal of Basic and Applied Science