Stability indicting liquid chromatography method for the simultaneous quantification of Nortriptyline and Pregabalin pharmaceutical formulations
N Sai Prudhvi, M Prasada Rao, A Dharma Teja, M Ramu, B Narasaimha Murthy
A simple, accurate and stability indicating rapid High Performance Liquid Chromatographic method was developed and validated for the simultaneous determination of Nortriptyline and Pregabalin in pure and its pharmaceutical formulations using Hypersil ODS C18 column (250 X 4.6 mm, 5μ) as stationary phase and Acetonitrile, Methanol and 0.1M sodium perchlorate in the ratio of 40:30:30 (v/v) as mobile phase at pH 5.6, flow rate of 1 ml/min with isocratic elution. The eluted compounds were detected by using UV7000 detector at detection wavelength 205 nm. The retention times of Nortriptyline and Pregabalin are found to be 5.21 and 6.66 min respectively. The linearity ranges was 1-6 µg/ml and 7.5-45 µg/ml with LOD values 0.03 µg and 0.25 µg and LOQ values are 0.10 µg and 0.9 µg for Nortriptyline and Pregabalin respectively. Which were linear enough with correlation coefficient 0.999 in all the cases. The percentage recovery was found to be in range of 98.12 – 99.82% and 98.01 – 99.35% for Nortriptyline and Pregabalin respectively. The both the drugs were subjected to acid, base, hydrolysis, oxidation, photolytic and thermal degradation conditions. The degradation products of Nortriptyline and Pregabalin were well resolved from the pure drug with significant differences in their retention time values. This validated method was applied for the simultaneous estimation of Nortriptyline and Pregabalin in commercially available formulation sample.