Stable Liquid Chromatography Method for the Resolution and Quantification of Related Impurities of Fosamprenavir in Bulk and Pharmaceutical Formulations

Abstract

Highly resolved and validated Liquid Chromatography method was developed for the separation and quantification of fosamprenavir and its related impurity 2 and 5 in bulk and pharmaceutical formulations. Separation of fosamprenavir and its impurities was achieved on prontosil ODS C18 column using mobile phase composition of methanol and 0.1 m sodium acetate in the ratio of 40:60 (v/v) at pH 5.9 as mobile phase at a flow rate of 0.9 mL/min in isocratic condition. Uv detection of the eluents was monitored at a wavelength of 246nm. In these conditions, well resolved peaks were observed at a retention time of 8.67, 5.73 and 4.00 min for fosamprenavir, Impurity 2 and 5, respectively. Calibration curve was plotted in the concentration range of 75-450 µg/mL for fosamprenavir and 1-6 µg/mL for impurity 2 and 5. Forced degradation study confirms that the method can separate the known and unknown impurities of fosamprenavir and the % degradation was found to be very less in all the stress conditions. Hence the method is suitable for the identification and quantification of impurities 2 and 5 along with fosamprenavir in bulk drug and formulations.