Development of uv-spectrophotometric method for the simultaneous estimation of nateglinide and piperine in combined tablet dosage form

Simple, accurate, precise, economical procedure entailing neither irksome sample treatment nor tedious extraction process have been developed for the simultaneous estimation of piperine and nateglinide in a combined tablet dosage form of nateglinide and piperine using UV-Spectrophotometry method. Piperine is an alkaloid obtained from Piper nigrum Linn., is known to modify the biotransformation of the drugs by inhibiting Cytochrome P450 forms. Piperine inhibits the bio-transformation and metabolism of nateglinide leading to higher levels of drug in systemic circulation, thus increases the bioavailabilty when co-administered with nateglinde. Nateglinide and piperine have shown absorbance maxima at 258nm and 244nm respectively, in methanol and the linearity was obeyed over the concentration range of 50–250μg/ml and 5–25μg/ml respectively for nateglinide and piperine. The validation parameters like precision, accuracy, limit of quantitation (LOQ), limit of detection (LOD), were determined according to ICH guidelines. All the results were found to be within the limits.