Simultaneous UV Spectrophotometric Method for Estimation of Sitagliptin phosphate and Metformin hydrochloride in Bulk and Tablet Dosage Form

Two simple, precise and economical UV methods have been developed for the simultaneous estimation of Sitagliptin phosphate and Metformin hydrochloride in bulk and pharmaceutical dosage form. Method A is Absorbance maxima method, which is based on measurement of absorption at maximum wavelength of 266 nm and 232 nm for Sitagliptin phosphate and Metformin hydrochloride respectively. Method B is area under curve (AUC), in the wavelength range of 244-279 nm for Sitagliptin phosphate and 222-240 nm for Metformin hydrochloride. Linearity for detector response was observed in the concentration range of 25-225μg/ml for Sitagliptin phosphate and 2-12 μg/ml for Metformin hydrochloride. The accuracy of the methods was assessed by recovery studies and was found to be99.64 % and 98.98% for Sitagliptin phosphate and Metformin hydrochloride. The developed method was validated with respect to linearity, accuracy (recovery), precision and specificity. The results were validated statistically as per ICH Q2 R1 guideline and were found to be satisfactory. The proposed methods were successfully applied for the determination of for Sitagliptin phosphate and Metformin hydrochloride in commercial pharmaceutical dosage form.