Nanocapsules embedded in microparticles for enhanced oral bioavailability and efficacy of Lopinavir as an anti-AIDS drug

Abstract

Lopinavir (LPV), an efficient drug for HIV infection treatment, was incorporated into biodegradable PLGA nanocapsules (NCs) embedded in microparticles (MCPs) using the spray-drying technique in an attempt to bypass the P-gp efflux and protect the drug from CYP3A pre-systemic metabolism without ritonavir (RTV). SEM observations confirmed the formation of NCs and their entrapment in the MCPs. LPV-loaded NCs and free LPV were released from the MCPs at pH of 7.4 as evidenced by in vitro release studies. Results obtained from rat studies showed a two-fold higher bioavailability of LPV following oral administration of the optimal formulation than Kaletra^®, the marketed drug, showing that when properly entrapped, LPV can be effectively protected from CYP degradation in the gut as well as from the liver following systemic absorption. It was also shown that serum derived from rats following LPV oral administration in two formulations and Kaletra^® significantly decreased the multiplication of HIV-1 in cultured SupT1 cells. Furthermore, the LPV formulations markedly restricted the titre of infectious HIV-1 production compared with Kaletra^® confirming the improved antiviral activity of LPV delivered in the rat blood circulation by the nanocapsules embedded in microparticle formulations.

Keywords:

• Lopinavir
• nanocapsules
• microparticles
• HIV
• bioavailability
• oral
• antiviral

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgements

The in vitro antiviral work was carried out in the Peter A. Krueger Laboratory with the generous support of Nancy and Lawrence Glick and Pat and Marvin Weiss. Dr Ponnandy Prabhu is a fellow of PBC (for outstanding Post-Doctoral Researchers from India) of the Council for Higher Education in Israel. This work was supported in part by an NIH grant (P01 GM091743).