Ion pair

  Two simple and sensitive visible spectrophotometric methods (A and B) have been developed for the quantitative estimation of Pioglitazone, in bulk drug and pharmaceutical dosage forms. Methods were based on the formation of Pale yellow coloured and green coloured chromo gens, which were measured 267 nm and 297 nm, respectively. The results obtained with the proposed methods are in good agreement with the labeled amounts when tablet dosage forms were analyzed.  For the first method, UV-spectrophotometry, standard solutions were measured at 267 nm. The first method was linear from 2.5-20 mg/mL. The second method was based on the formation of an ion association complex with Methyl orange (MO) and Bromocresol Green (BCG).The assay was found to be linear over the concentration range of 2.5-20 µg/mL. The wavelengths were selected dependent on the maximum obtained values. The formation of ion- pairs are formed between secondary amino group of PIO and MO, BCG reagents via the protonated nitrogen atom. The proposed methods were validated according to the ICH guidelines (1996) with respect to specificity, linearity, accuracy, precise and robustness. The results demonstrated that the procedure is accurate, precise, specific and reproducible (percent relative standard deviation