Fabrication of TPGS decorated Etravirine loaded lipidic nanocarriers as a neoteric oral bioavailability enhancer for lymphatic targeting.

Abstract

Etravirine (ERVN) is a potential NNRTI (non-nucleoside reverse transcriptase inhibitor) in treating HIV infection. It possesses extremely low oral bioavailability. The present research aims to optimize the formulation and characterization of TPGS-enriched ERVN-loaded lipid-based nanocarriers (NLCs) for HIV-infected patients. The formulation, ERVN-TPGS-NLCs, was optimized by central composite rotational design using a modified-solvent emulsification process. Various characterization parameters of NLCs were evaluated, including globule size of 121.56 ± 2.174 nm, PDI of 0.172 ± 0.042, the zeta potential of - 7.32 ± 0.021 mV, %EE of 94.42 ± 8.65% of ERVN and %DL was 8.94 ± 0.759% of ERVN and spherical shape was revealed by TEM. PXRD was also performed to identify the crystallinity of the sample. In-vitro drug release showed % a cumulative drug release of 83.72 ± 8.35% at pH 1.2 and 90.61 ± 9.11% at pH 6.8, respectively, whereas the % cumulative drug release from drug suspension (ERVN-S) was found to be 21.13 ± 2.01% at pH 1.2 and 24.84 ± 2.51 at pH 6.8 at the end of 48 h. Further, the intestinal permeation study and confocal microscope showed approximately three-fold and  two-fold increased permeation in ERVN-TPGS-NLCs and ERVN-NLCs across the gut sac compared to ERVN-S. Hemolysis compatibility and lipolysis studies were performed to predict the in-vivo fate of the formulation. The pharmacokinetic study revealed a 3.13-fold increment in the relative bioavailability, which agrees with the ex-vivo studies, and lymphatic uptake was validated by using cycloheximide along with designed formulation, which showed the impact of lymphatic uptake in AUC. This study ensures that ERVN-TPGS-NLCs take lymphatic uptake to minimize the first-pass metabolism followed by improved oral bioavailability of ERVN. Thus, the enhanced bioavailability of ERVN can reduce the high dose of ERVN to minimize the adverse effects related to dose-related burden.