Sitagliptin phosphate: Development of a dissolution method for coated tablets based on in vivo data for improving medium sensitivity

Abstract

Sitagliptin phosphate is a drug used to treat diabetes mellitus type 2, and it belongs to a new therapeutic class called dipeptidyl peptidase IV inhibitors. This hypoglycemic drug is commercially available in coated tablets containing 25, 50, and 100 mg of sitagliptin base. The purpose of this study was to develop and validate the conditions for the dissolution test by investigating a possible in vivo-in vitro correlation. Several parameters were tested to develop the method, and the following conditions were considered satisfactory: pH 6.8 phosphate buffer, 900 mL of dissolution medium, temperature at 37 ± 1 °C, paddle apparatus, and rotation speed at 50 rpm. The dissolved percentage of STG was quantified by high performance liquid chromatography. The sink condition and specificity were determined in all media tested during method development. The parameters evaluated to validate the method were specificity, linearity, precision, and accuracy. The stability of the sample in phosphate buffer solutions for 24 h was also determined. The method is linear in the range of 10.0-70.0 μg/mL, precise, with RSD values less than 2%, and accurate (mean recovery 98.51%). The dissolution method as developed and validated supplied a good IVIVC when employing pH 6.8 phosphate buffer medium, which can be used in quality control of sitagliptin coated tablets since no official method has been described.