Preparation and Evaluation of Efavirenz Loaded Solid Lipid Nanoparticle for improving Oral Bioavailability

Abstract

Efavirenz (EFV) is a highly lipophilic, oral non-nucleoside reverse transcriptase inhibitor reported to have poor aqueous solubility and bioavailability used for the treatment of HIV. In the present research work, solid lipid nanoparticles loaded with efavirenz were formulated for oral drug delivery and to increase the bioavailability of efavirenz. Solid lipid nanoparticles loaded with efavirenz were prepared through the microemulsion method followed by the lyophilization technique using glyceryl monostearate as lipid and Tween 80 as a surfactant. Solid lipid nanoparticle formulation was evaluated using different parameters including Scanning electron microscopy (SEM), drug entrapment efficiency (EE%), in vitro drug release study, differential scanning calorimetry, and powder X-ray diffractometry. Solid lipid nanoparticles loaded efavirenz showed 60.41% drug entrapment. Differential scanning calorimetry and powder X-ray diffractometry study indicate solid lipid nanoparticles loaded efavirenz is crystalline, stable and there is no interaction between the excipients and drug. In vitro drug release study of EFV-SLN showed 88.2±0.12% drug release which is better as compared to marketed formulation drug release. EFV-SLN drug release study data demonstrated a better fit for the first-order kinetics and confirmed the non-Fickian-diffusion mechanism. Prepared SLN formulation has shown good stability at 45∘C and 75% relative humidity (RH) for 150 days. These results determined that the developed EFV-SLN formulation exhibited a promising antiviral activity to treat HIV and has great potential for boosting the oral bioavailability of Efavirenz.