Validated stability-indicating method for estimation of related substances of paroxetine in active pharmaceutical ingredient and its pharmaceutical dosage forms

Abstract

Validated stability-indicating analytical method was established for the quantitative determination of paroxetine and its related substances in API and it’s finished product in the presence of degradation products. To prove the stability-indicating nature of the method, stress studies were carried out. The method was developed by using (Waters, symmetry C18, 250×4.6 mm, 5 μm column) employing water:THF: TFA 90:10:1 (v/v/v) as mobile phase-A and mobile phase-B consist of ACN:THF: TFA the proportion of 90:10:1 (v/v/v) in a gradient mode with a flow rate of 1.5 mL/min was chosen. The column and sample cooler were kept at 45°C and 5°C respectively and 285 nm used as detection wavelength. Significant degradation observed in alkaline conditions, whereas no signification decay in drug stability was observed in other decomposition environments. Method development as well as optimisation studies were done by analysing the samples generated in the stress studies and spiked samples. Mass balance was found to be in the range of 90.3 and 100.1%, signifying the method is stability-indicating. All earlier analysis methods for the analysis of paroxetine have not been entirely validated by considering all the degradation products. The established method validated as per ICH Q2 (R1) and considered as linear, specific, accurate, precise, rugged, robust and found to be suitable for the routine and stability analysis of the product.