A new validated, stability-indicating, rp-uplc method for determination of donepezil hydrochloride assay and impurities content in bulk drug

A simple, economic, and time-efficient stability-indicating, reverse-phase ultra-performance liquid chromatographic (RP-UPLC) method has been developed for analysis of donepezil hydrochloride in the presence of both impurities and degradation products generated by forced degradation. When donepezil hydrochloride was subjected to acid hydrolytic, oxidative, base hydrolysis, photolytic, and thermal stress, degradation was observed after oxidative and base hydrolysis. The drug was found to be stable to other stress conditions. Successful chromatographic separation of the drug from impurities formed during synthesis and from degradation products formed under stress conditions was achieved on a Waters Acquity C18, 50 mm x 2.1mm, 1.7µ particle size column, UV detection 286nm and a gradient elution of trifluoro acetic acid, acetonitrile and methanol as mobile phase. The method was validated for specificity, precision, linearity, accuracy and robustness and can be used for quality control during manufacture and for assessment of the stability of samples of donepezil hydrochloride. To the best of our knowledge, a validated stability indicating UPLC method which separates all the eight impurities disclosed in this investigation has not been published elsewhere. Total elution time was about 8 min which allowed quantification of more than 100 samples per day.