Three rapid spectrophotometric methods were developed for the determination of sunitinib based on the formation of ion-pair complex in acidic medium with bromocresol purple, bromothymol blue, and bromophenol blue. The formed ion-pair complexes, extractable with chloroform, were measured at 422 nm for bromocresol purple, 425 nm for bromothymol blue and 427 nm for bromophenol blue. All these methods were optimized for the pH of buffer and the volume of the reagent. The methods were linear over the range of 1-200 µg/mL for bromocresol purple, 1-150 µg/mL for bromothymol blue, and 2-200 µg/mL for bromophenol blue with a very low limit of quantification and acceptable accuracy and precision. Using the proposed methods for determination of sunitinib in pharmaceutical dosage forms showed reliable results comparable to previously published method.
Keywords: Bromocresol purple; Bromophenol blue; Bromothymol blue; Ion-pair complex formation; Sunitinib.