Formulation and Characterization of Solid Lipid Nanoparticles of Rifampicin

Objective: In this study, solid lipid nanoparticles of rifampicin were prepared by the emulsion solvent diffusion method using stearic acid to retard release and achieve the required release profile for the treatment of tuberculosis. Materials and Methods: The polymer DL-lactide/glycolide copolymer (PLGA) and lipid were dissolved in the organic phase separately. Stearic acid and rifampicin were dissolved in a mixture of chloroform and methanol. The resulting organic solution was poured into polyvinyl alcohol and homogenized. The organic solvents were removed using a rotary flash evaporator. The SLNs were recovered by centrifugation and lyophilized. Results: The twelve prepared formulations showed that the highest encapsulation efficiency was 78.79 +/- 0.1%. In vitro release studies were performed in which the particle stability was found to be enhanced by poly vinyl alcohol (PVA), which forms a barrier to the release of the incorporated drug. The stability study conducted for three months revealed that formulations stored at room temperature were prone to fungal growth whereas formulations stored in the refrigerator were stable. Conclusion: The ultimate goal of controlled drug release is to maximize therapeutic activity while minimizing the negative side effects of the drug. In this regard, solid lipid nanoparticles have emerged as a novel drug carrier system for the hydrophobic anti-tubercular drug, rifampicin.