Method development, validation and forced degradation studies of atomoxetine hydrochloride by RP- HPLC

Abstract

A RP-HPLC method was developed for the quantitative determination of atomoxetine hydrochloride in bulk drug and tablet formulation, recently used as an antidepressant agent. Forced degradation studies were performed on bulk sample of atomoxetine hydrochloride using acid (0.5 N hydrochloric acid), base (0.5 N sodium hydroxide), oxidative (3.0 % v/v hydrogen peroxide), thermal (60°) and photolytic (UV) degradation. Mild degradation of the drug substance was observed for thermal degradation and photolytic degradation, while considerable degradation observed during acid - base hydrolysis and oxidative stress. The chromatographic method was fine tuned using the samples generated from forced degradation studies. Good resolution between the peaks corresponds to degradation products and the analyte was achieved on a Lichrospher 100 RP-180, C-18 column (250 mm, 4.0 mm id, 5 mcm). The mobile phase consists of a mixture of aqueous sodium dihydrogen phosphate (pH 2.86 ± 0.1) and acetonitrile (50:50 v/v). The stress sample solutions were assayed against the qualified reference standard of atomoxetine hydrochloride indicating that the developed method is stability indicating. Validation of the developed method was carried out as per ICH requirements