ABSTRACT
The present work describes development and validation of four different stability indicating methods for quantitative analysis of cefdinir (CFD) in bulk powder and pharmaceuticals, and in the presence of its acid and alkaline induced hydrolytic degradation products. The first method is based on derivative spectrophotometry. First derivative spectrophotometry was applied where CFD was determined at 313.4 nm in the presence of its alkaline degradation product and also second derivative spectrophotometry where CFD was determined at 298.2 nm in the presence of its acid degradation product. The second method is based on the first derivative of ratio spectrophotometry of CFD at 312 nm in the presence of its acid degradation product and at 310.2 nm in the presence of its alkaline degradation product. The third method is based on the mean centering of ratio spectrophotometry where the drug was determined at 288.4 and 284.8nm in laboratory prepared mixtures with its acid and alkaline degradation products, respectively. The fourth method is HPTLC-densitometry using diethylether-methanol-water-glacial acetic acid (6: 3: 1: 0.05, v/v) as a developing system. Due to simplicity, rapidity and accuracy of the proposed stability indicating methods, they are effective for quality control analysis.
ABSTRACT
Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride (IMD) in the presence of both its alkaline (AKN) and oxidative (OXI) degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra (D4) which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one (DD-RD) by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method (DD-DR1) at 243.2 nm, while method D is the mean centering of ratio spectra (MCR) at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression (PCR) and partial least-squares (PLS), respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.
ABSTRACT
Two simple,accurate,precise and economic spectrophotometric methods have been developed for simultaneous determination of Atorvastatin calcium (ATR) and Ezetimibe (EZ) in their bulk powder and pharmaceutical dosage form.Method (Ⅰ) is based on dual wavelength analysis while method (Ⅱ) is the mean centering of ratio spectra spectrophotometric (MCR) method.In method (Ⅰ),two wavelengths were selected for each drug in such a way that the difference in absorbance was zero for the second drug.At wavelengths 226.6 and 244 nm EZ had equal absorbance values; therefore,these two wavelengths have been used to determine ATR; on a similar basis 228.6 and 262.8 nm were selected to determine EZ in their binary mixtures.In method Ⅱ,the absorption spectra of both ATR and EZ with different concentrations were recorded over the range 200-350,divided by the spectrum of suitable divisor of both ATR and EZ and then the obtained ratio spectra were mean centered.The concentrations of active components were then determined from the calibration graphs obtained by measuring the amplitudes at 215-260 nm (peak to peak) for both ATR and EZ.Accuracy and precision of the developed methods have been tested; in addition recovery studies have been carried out in order to confirm their accuracy.On the other hand,selectivities of the methods were tested by application for determination of different synthetic mixtures containing different ratios of the studied drugs.The developed methods have been successfully used for determination of ATR and EZ in their combined dosage form and statistical comparison of the developed methods with the reported spectrophotometric one using F and Student's t-tests showed no significant difference regarding both accuracy and precision.
ABSTRACT
Three simple and sensitive methods were developed for the determination of a mixture of Rabeprazole sodium RB and Domperidone DP without prior separation. The first method A, isoabsorptive point comprised of measurement the total content of the mixture at their isoabsorptive point, while the content of RB was determined by measuring the first order derivative of its spectra at 231 nm, and the content of DP could be calculated by subtraction. The second method, B was based on the mean centering of ratio spectra, the concentration of RB was determined by measuring the amplitude at 256.4 nm and the concentration of DP was determined by measuring the amplitude at 311.8 nm. The third method C, dual wavelength method, the wavelengths selected for determination of Rabeprazole were 270 nm & 301 nm, whereas, the wavelengths selected for determination of Domperidone were 260 and 297.2 nm. The percentages mean accuracy for RB were 99.74 ± 0.498 % for method (A), 100.52 ± 0.478 % for (B) and 100.43 ± 0.502 % for (C) respectively. And that of DP were 100.28 ± 0.488 % for method (A), 99.24 ± 0.551 % for (B) and 99.95 ± 0.516 % for (C) respectively. The obtained results were statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision.