The Spectrophotometric Determination of Olanzapine via Coupling with Diazotized p-Nitroaniline


A new spectrophotometric method has been developed for the assay of olanzapine (OLN.) in pure and dosage forms. The method is based on the diazocoupling of (OLN.) with diazotized p-nitroaniline in alkaline medium to form a stable brown colored water-soluble azo dye with a maximum absorption at 405 nm. The variables that affect the completion of reaction have been carefully optimized. Beer’s law is obeyed over the concentration range of (0.5-45.0 μg.mL-1) with a molar absorptivity of 1.5777×104 The limit of detection was 0.3148 μg.mL-1 and Sandell’s sensitivity value was 0.0198 μ The proposed method has been applied successfully to the determination of olanzapine in tablet pharmaceutical preparations.