Three Spectrophotometric Methods for Determination of Alogliptin Benzoate and Pioglitazone HCl in Combined Tablet Dosage Form

Abstract

Three simple, accurate and precise spectrophotometric methods have been developed and validated for simultaneous determination of alogliptin benzoate and pioglitazone HCl in bulk and in tablet dosage form. Method I was area under curve method and it involved measurement of area at selected wavelength range; the selected wavelength range was 275-285 nm for ALG and 263-273 nm for PIO. Method II involved the use of first derivative of ratio spectra (1DD) using PIO (10 μg/mL) as a divisor for ALG determination, then peak amplitude at 300 nm was directly proportional to ALG concentration; and ALG 5 μg/mL as a divisor for PIO determination, then peak amplitude at 277 nm was directly proportional to PIO concentration. Method III was ratio difference method and it involved measurement of difference in amplitudes (ΔP) in the ratio spectra; ΔP292-238 was directly proportional to ALG concentration and ΔP260-239 was directly proportional to PIO concentration. The three proposed methods were linear over the range 5-30 μg/mL for ALG and 5-50 μg/mL for PIO. The methods were validated according to ICH guidelines. Statistical comparison of the proposed methods with the reported HPLC method using F and t tests showed no significant difference regarding both accuracy and precision.