LC Evaluation of In Vitro Release of AZT from Microemulsions

A reversed phase LC method was developed and validated to analyze the in vitro release of AZT from microemulsions. A mobile phase of acetonitrile:water (15:85) was used. The method validation showed good selectivity and linearity (r = 0.9993) for sample concentrations ranging from 0.6 to 100.0 μg mL^?1. The RSD values (0.7–4.3%) and percentage recovery (88.1–109.8%) were within acceptable limits. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.012 and 0.041 μg mL^?1. Quantitative analysis of the values obtained in the drug release assay indicates that the microemulsions used promote sustained release of AZT, which follows a Fickian diffusion mechanism.