The aim of the research was to study the stability, release profile, pharmacokinetic and biodistribution properties of zidovudine (AZT)-solidified reverse micellar microparticulate. Lipid matrices formulated with Phospholipon® 90H and goat fat at ratios of 1:1, 2:1, 3:1 and 2:3 were used to prepare AZT-loaded SLM by melt dispersion followed by lyophilization. In vitro release studies of the drug were carried out using a sequential drug release method in both SGF (pH 1.2) and SIF (pH 7.2) while the in vivo drug release studies were carried out using Wistar albino rats. The result of our findings showed that the drug is compatibility with the lipid matrix with the 1:1 showing the most stable microparticle preparation which was then optimized. The formulations showed a concentration dependent increase in their concentration maximum (Cmax) with values of 116.05 µg/ml, 124.21 µg/ml, 128.95 µg/ml, 138.95 µg/ml and time to reach maximum concentration (Tmax) values of 5h, 8 h, 8 h, and 5 h for batches B1, B2, B3 and B4 containing 1 %, 2 %, 3 % and 5 % of AZT respectively. The area under curves (AUCs) of the microparticles formulated showed that the bioavailabilities of the microparticles were comparable to that of the conventional release tablet. The biodistribution studies of the microparticles in rats showed highest concentration of the drug in the liver with the least in the brain and higher biodistribution in various organs than pure AZT. The data suggested that SLM could be a promising drug delivery system to improve on the shortcomings of pharmacokinetics and bio-distribution properties of conventional AZT tablets like fluctuation in blood levels of the drug
