Solid Lipid Nanoparticles of Simvastatin:Pharmacokinetic and Biodistribution Studies on Swiss Albino Mice

The Purpose of this study was to investigate role of solid lipid nanoparticles (SLNs) on oral bioavailability of simvastatin, and to study the distribution of drug in heart, lungs, liver, spleen, kidney, stomach and intestine. To achieve goal, the SLNs of simvastatin were developed and optimized using 23 factorial designs. Optimized formulation was radiolabelled with technetium- 99m and evaluated for pharmacokinetics and biodistribution parameters in Swiss albino mice. At various time points mice were sacrificed humanly and blood/organs were isolated. Percent activity/gram (% A/G) for blood and each organ was determined by gamma ray counter. The optimized formulation of SLN of simvastatin demonstrated a relative bioavailability of 186% in comparison to simvastatin suspension. It is suggested that the transport of SLNs through the intestinal lymphatics avoids presystemic hepatic metabolism and therefore enhances bioavailability. Biodistribution study revealed higher % A/G of Tc 99m in liver for simvastatin suspension when compared to SLNs after 4 hours of administration indicating the ability of SLNs to bypass liver and thus, minimizing the presystemic metabolism.