Tenofovir Alafenamide Fumarate Microspheres, Process Parameters for Enhanced Permeability and Liver Targeting

Aims: Chronic hepatitis B (CHB) infection is a serious global health problem and one of the main causes of chronic liver disease, cirrhosis. Tenofovir Alafenamide Fumarate (TAF) is a prodrug of Tenofovir, a nucleotide analogue with limited oral bioavailability. TAF is considered to be a BCS Class III substance (high solubility, low permeability). The aim of the study was to develop the Tenofovir Alafenamide Fumarate (TAF) microspheres to improve permeability. Study design: Preparation and Evaluation of Microspheres. Place and Duration of Study: Department of pharmaceutics, Mallareddy Institute of Pharmaceutical Sciences, Affiliated to JNTUH, Hyderabad, Telangana, India, between January 2018 and June 2019. Methodology: TAF loaded chitosan microspheres were prepared by emulsion cross linking method using glutaraldehyde as cross-linking agent. The prepared microspheres were characterized by morphology, size distribution, encapsulation efficiency. The permeability study was evaluated by Ex-vivo permeation studies. The optimized formulation was subjected to FTIR studies to examine the Drug Excipient Compatibility. Results: Scanning Electron Microscopy (SEM) studies indicated that the microspheres are spherical in shape. The optimized formulation has average particle size of 11.00 ± 0.05 µm, the encapsulation efficiency 68 ± 0.04% and the percentage (%) yield of 94%. FTIR studies indicated that the drug and polymer are compatable with each other. In Ex-vivo permeation studies of optimized formulation 80% of drug was permeated with in 60 min. Conclusion: TAF microspheres could improve the absorption by increasing the permeability.