extractive spectrophotometry

Two simple and sensitive ion-pairing spectrophotometric methods have been developed for the assay of saxagliptin in pure form and in tablet dosage form. The developed methods involve formation of yellow colored chloroform extractable ion-pair complexes of the drug with Bromocresol Green (BCG) and Bromothymol Blue (BTB) in acidic medium. The extracted complexes showed absorbance maxima at 420, 415 nm for BCG, BTB, respectively. Beer’s law is obeyed in the concentration ranges 10-50 μg ml-1 in both methods with molar absorptivity of 3.164 x 103, 4.305 x 103, L mole-1 cm-1 for BCG and BTB, respectively. These methods have been successfully applied for the assay of drug in tablets. Results of analysis were validated statistically and through recovery studies.