P. Sreelatha

Compendia methods from the USP (United States pharmacopoeia) are widely used in Pharmaceutical drug product testing. However USP methods are under uninterrupted revision to improvement. Donepezil USP monograph is having two methods to quantify donepezil Related substance. The present research work is a single, simple and economic stability indicating impurity profiling method has been developed for scrutiny of Donepezil hydrochloride. Successfully Chromatographic separation has been achieved on an Inertsil C8 3v (150mm x 4.6mm) 3μm with buffered mobile phase consisting of solvent A (mixture of 0.1M phosphate (pH 2.8) buffer and methanol in the ratio 90: 10 (v/v); respectively) and Solvent B (mixture of 0.1 molar (M) phosphate ( pH 2.8) buffer , Acetonitrile and methanol in the ratio 20:20: 60 (v/v); respectively) delivered at flow rate of 1.0 mL/min and the detection wavelength is 215 nm. The drug was subjected to the stress conditions. Donepezil hydrochloride was found to deteriorate significantly in basic, oxidative stress conditions and stable other degradation conditions. One degradant was observed in the stability studies, Which is crossing Identification threshold .the same was isolated and structural elucidation was carried out by H-NMR, Mass spectroscopy. The developed method was corroborated as per ICH guidelines.

A simple, rapid, accurate, precise and economical reverse phase high performance liquid chromatographic method was developed for simultaneous quantification of two anti-hypertensive drugs Olmesartan and Chlorthalidone. The separation of both the drugs was achieved on BDS C18 250mm x 4.6 mm, 5m using a mobile phase of 10 mM orthophosphoric acid buffer and acetonitrile (45:55v/v) at a flow rate of 1.0 mL min-1 and detection was performed at 212 nm using photodiode array (PDA) detector. The drug was subjected to various ICH prescribed stress conditions including hydrolysis (neutral, acid and alkaline), oxidation, photolysis and thermal degradation. The proposed method was validated with respect to specificity, linearity, accuracy, and precision, limit of detection (LOD), limit of quantitation (LOQ), stability and robustness as per ICH guidelines. The proposed analytical method could effectively separate the drug from its degradation products employed as stability indicating studies.