Visible Spectrophotometric Determination of Imatinib Mesylate in Bulk Drug and Pharmaceutical Formulations

Two new simple, sensitive and cost effective visible spectrophotometric methods were developed for the estimation of imatinib mesylate in both bulk drug samples and formulations. The first method (method A) was based on the oxidative coupling of the drug with the reagent namely 3-methyl-2-benzothiazolinone hydrazone and ferric chloride solution. The second method (method B) was based on the formation of ion pair complex of the drug with an acidic dye namely bromocresol green in acidic buffer solution followed by their extraction in chloroform. The absorbance of the chromogens was measured at the absorption maxima of 569 nm for mehod A and 417 nm for mehod B against the corresponding reagent blank. The method obeyed Beer's law between 25-350 mu g/mL for 3-methyl-2-benzothiazolinone hydrazone and 5.0-40 mu g/mL for bromocresol green. The results of recovery experiments indicated average recovery was above 99.81%. The interference studies also revealed the common excipients and other additives usually present in pharmaceutical dosage forms did not interfere in the proposed methods.