Determination of Ketotifen fumarate in raw material and pharmaceutical products using ion-pair formation

A simple and sensitive extractive spectrophotometric method has been described for the determination of Ketotifen. The developed method is based on the formation of a colored ion-pair complex (1:1 drug/dye) of Ketotifen and bromocresol green in buffer pH 3 and extraction in chloroform. The extracted complex shows absorbance maxima at 423 nm. Beer's law is obeyed in the concentration range of 5.15-61.91 mu g/ml. The proposed method has been applied successfully for the determination of drug in commercial tablets and syrup dosage form. No significant interference was observed from the excipients commonly used as pharmaceutical aids with the assay procedure.