VALIDATED STABILITY INDICATING ANALYTICAL METHOD AND IN-VITRO DISSOLUTION STUDIES OF EFAVIRENZ FORMULATION BY RP-HPLC
A reverse phase stability indicating HPLC method was developed for the analysis of efavirenz bulk and pharmaceutical formulations. The developed method was also utilized for in-vitro dissolution studies of efavirenz formulations. Acetonitrile and acetate buffer pH 3.4 was the mobile phase (75:25% v/v), with retention time of 4.007 min at a flow rate of 1.5 mL/min detected at 292 nm wavelength. Linear regression analysis calibration plot showed an excellent linearity between response and concentration in the range of 50-300 gmL-1. The regression coefficient was 0.999 and the linear regression equation was y = 7780x+11159. Limits of detection (LOD) and quantification (LOQ) were 0.238 and 0.793 gmL-1 respectively. The method was validated for accuracy, precision, specificity, robustness, detection and quantification limits, in accordance with ICH guidelines. The specificity of the method was ascertained by forced degradation studies by acid, alkali hydrolysis, oxidation and thermal degradation methods. The degraded products were well resolved from the analysis peak with significant differences at their retention time values. Wide linearity range, sensitivity, accuracy, short retention time and simple mobile phase indicate the method is suitable for routine quantification of efavirenz with high precision and accuracy.