Efavirenz-eudragit E-100 nanoparticle-loaded aerosol foam for sustained release: in-vitro and ex-vivo evaluation

The control of HIV infection using antiretroviral agents, especially through targeted delivery, has attracted extensive attention in the last decade. Recently, the vaginal route of administration has become the one most recommended for HIV infections during pregnancy. Efavirenz is a non-nucleoside reverse transcriptase inhibitor anti-HIV drug and its prolonged half-life helps achieve long-term pre-exposure prophylaxis of HIV-1 infections; it is used as a first-line drug in the treatment using combination therapy. Nanotechnology has received attention as a major area of research into drug delivery in recent years. The aerosol foam formulation is packed under pressure and contains therapeutically active ingredients that are released as foam on the activation of an appropriate valve system. The objective of this study was to develop an aerosol foam formulation of efavirenz nanoparticles for vaginal drug delivery. The nanoparticles were prepared using the emulsion solvent evaporation method and converted into an aerosol foam formulation with the addition of 0.1 mass % of sodium lauryl sulphate as a foaming agent and pressurised with 1,1,1,2-tetrafluroethane. The nanoparticles containing the formulation and aerosol foam formulation were individually characterised by applying various tests such as particle size, zeta potential, pH, viscosity, drug content, entrapment efficiency, drug release studies and release kinetics. The compatibility of the materials was evaluated using FT-IR, polymorphic changes by TGA-DSC and also the morphological properties using SEM study. Foam density, bubble size and collapse time were evaluated in the aerosol-foam formulation; in addition, the drug content and release studies were compared with nanoparticle formulation. The results revealed that the nanoparticle-containing formulation and aerosol formulations were stable and the foam emerged as grade one with fine bubbles and became coarser over time. (C) 2014 Institute of Chemistry, Slovak Academy of Sciences