New Extractive Spectrophotometric Methods for the Determination of Olanzapine in Pharmaceutical Formulations Using Bromocresol Green

Abstract

 Two new spectrophotometric methods have been developed and validated for the assay of olanzapine (OLP) in bulk and in pharmaceuticals. The first method (method A) is based on the formation of yellow ion-pair complex between the OLP and bromocresol green (BCG) at pH 5.50 ± 0.10. The ion-pair complex formed was extracted with dichloromethane and the absorbance was measured at 410 nm (0.25-12.50 µg/mL OLP). The second method (method B) is based on the breaking of the yellow OLP-BCG ion-pair complex in alkaline medium followed by the measurement of the blue color of the dye at 620 nm (0.2-5.0 µg/mL OLP).