Development and validation of RP-HPLC method for simultaneous determination of glipizide, rosiglitazone, pioglitazone, glibenclamide and glimepiride in pharmaceutical dosage forms and human plasma

A simple, high performance liquid chromatographic method has been developed for the simultaneous determination of glipizide, rosiglitazone, pioglitazone, glibenclamide and glimepiride in pharmaceutical dosage forms and human plasma. The elution was performed using a mobile phase mixture of 0.05% Triethylamine (pH-3.5, adjusted with ortho phosphoric acid), acetonitrile and methanol in the ratio of 55:15:30 at a flow rate of 1 ml min^?1 on a phenomenex C₁₈ column (150 × 4.6 mm, i.d., 5 ??m) at ambient temperature. The drugs were monitored at a wavelength of 248 nm and were separated within 20 min. Mixtures of formulations were prepared in suitable dilutions and plasma samples were prepared by extraction with acetonitrile. The method was successful in detecting the drugs at a concentration of less than 0.1 ??g ml^?1 for each drug and %RSD for intra- and inter-day studies was found to be less than 4.34 for all the selected concentrations. Moreover, the method was validated as per ICH guidelines and the results were found to be within the acceptable range. Hence, the proposed method can be used for the routine quality control of the drugs and can also be applied to pharmacokinetic studies.