Preparation, Characterization and Evaluation of Elvitegravir-Loaded Solid Lipid Nanoparticles for Enhanced Solubility and Dissolution Rate

Purpose: To enhance the aqueous solubility and dissolution rate of elvitegravir (EVG) by formulating the drug as solid lipid nanoparticles (SLNs) using solvent injection method.
Methods: EVG-loaded SLNs were prepared by solvent injection method. Four different formulations of SLN were prepared using gelucire - 44/14 as lipid core in ethanol, soya lecithin as emulsifier, and polysorbate 80 as surfactant in the aqueous phase. The SLNs were characterized for various physical properties, including particle size, zeta potential, polydispersity, release profile and entrapment efficiency.
Results: The yield of SLNs was in the range 151.0 ± 2.4 to 199.1 ± 2.7 nm. Significant changes were observed in mean particle size (nm), Z - potential (mV) and polydispersity index (PDI) of the SLNs by varying the concentration of cryoprotectant. EVG – SLNs demonstrated a 800 – 1030-fold enhancement in aqueous solubility compared with plain EVG. The dissolution efficiency (DE) for SLNs was > 63 % in all cases and increased up to 83 % with increasing lipid load.
Conclusion: Successful preparation and characterization of elvitegravir–loaded solid lipid nanoparticles by solvent injection method has been accomplished in this study.

Keywords
Elvitegravir; Solid lipid nanoparticles; Cryoprotectant; Lipid load; Entrapment efficiency