Visible Spectrophotometric Determination of Gefitinib in Bulk Drug and Pharmaceutical FormulationsAuthor(s): Murali Balaram Varanasi, Mushraff Ali Khan, Venkateswara Rao Jangala and Bulusu Bhanu Teja
Two new simple, sensitive and cost effective visible spectrophotometric methods were developed for the estimation of gefitinib in both bulk drug samples and tablets. These two methods are based on the formation of ion pair complexes of the drug with two acidic dyes namely bromocresol green (Method A) and bromophenol blue (Method B) in acidic buffer solution followed by their extraction in organic solvent (chloroform). The absorbance of the organic layer for both the methods was measured at their respective absorption maxima at 538 nm for bromocresol green and 429.5 nm for bromophenol blue against the corresponding reagent blank. The methods obeyed Beer’s law between 10-100 µg/mL for bromocresol green and 1-8 µg/mL for bromophenol blue. The interference studies also revealed the common excipients and other additives usually present in pharmaceutical dosage forms did not interfere in the proposed methods. The methods were statistically evaluated and the proposed methods are precise, accurate, sensitive, and cost effective and can be used in routine analysis in quality control laboratories.