Design and in vitro evaluation of tenofovir-loaded vaginal gels for the prevention of HIV infections

Infection with the human immunodeficiency virus (HIV) is affecting women disproportionally with increasing incidence rates over the last decades. Tenofovir is one of the most commonly used antiretroviral agents, which belongs to the nucleoside/nucleotide reverse transcriptase inhibitor family, for the prevention of HIV acquisition. In scope of this study, a thermogelling system containing tenofovir-loaded chitosan nanoparticles for the controlled release of tenofovir was developed and characterized. The in vitro release studies have shown that the burst release effect was decreased to 27% with f-TFV CS NPs-Gel. Gelation temperature of developed formulation was found as 26.6 +/- 0.2 degrees C, which provides ease of administration while gelation occurs after the administration to the vagina. The work of adhesion values was used as parameters for comparison of mucoadhesive performance and the mucoadhesion of f-TFV CS NPs-Gel was found as 0.516 +/- 0.136N.s at 37 degrees C. The biocompatibility of blank formulations was evaluated by cell viability studies using L929 cells, in which Gel+CS NPs formulation was found to be safe with 82.4% and 90.2% cell viability for 1:16 and 1:32 dilutions, respectively. In conclusion, an improved tenofovir containing vaginal gel formulation was successfully developed and evaluated for preventing HIV transmission.