Impurities.

In pharmaceutical products the presence of impurity assures the quality. It is important to identify potential source of impurities. Estimation of impurities is done by variety of chromatographic and spectroscopic techniques either alone or combination with other techniques. These different methods for detecting and characterizing impurities with IR, TLC, HPLC, MASS, NMR, HPTLC etc.  

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.