Development and Validation of Spectrophotometric Method for Simultaneous Estimation of Sitagliptin Phosphate and Simvastatin in Tablet Dosage Form

A simple and accurate method of analysis to determine Sitagliptin Phosphate (STG) and Simvastatin(SMV) in combined dosage forms was developed using simultaneous equation method at 267.0nm for Simvastatin and 238.0 nm for Simvastatin in spectra of their solutions in methanol: water(90:10). The calibration curves were linear [correlation coefficient (r) = 0.986 for STG and 0.998 for SMV] in concentration range of 10-50 μg/ml for STG and 5-25 μg/ml for SMV. The method was validated and found to be accurate, precise, and specific. The method was successfully applied to the estimation of STG and SMV in combined dosage tablet formulations.