The improvement of routine drug quality control analysis of some antihypertensive drugs using high-performance thin-layer chromatography densitometry method with greenness profile evaluation.

The common antihypertensive drugs are B-blockers and diuretics. For the determination of beta-blocker medicines (bisoprolol fumarate and carvedilol) and diuretic drug (Furosemide), new and accurate chromatographic method has been developed. The separation was achieved using a developing system that includes chloroform:methanol:ethyl acetate:ammonia (6:2:2:0.2 by volume) as a mobile phase and the bands were detected at 240 nm. The concentration ranges were 5-25, 1-7, and 1-3.5 µg/band for bisoprolol fumarate, carvedilol, and furosemide, respectively. This chromatographic approach is the first methodology for simultaneously determining bisoprolol fumarate, carvedilol, and furosemide in their pure forms and in their pharmaceutical dosage forms. The advantages of using known analytical procedures are their simplicity, speed, cost effectiveness, lack of laboriousness, and ability to save time as the three tablets are determined in one step and can be used for routine analysis of the investigated combinations in quality control laboratories. According to International Conference of Harmonization guidelines, the established procedures have been validated, and the results were statistically compared to those obtained by the reported reversed-phase-high-performance liquid chromatography methods using Student's t-test and F-test, with no significant difference between them, indicating that the proposed methods can be used for routine drug quality control analysis.

Two spectrophotometric methods for simultaneous determination of some antihyperlipidemic drugs.

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.