PROJECT SUMMARY Tenofovir prodrugs, tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide fumarate (TAF) are cornerstones of the first-line therapy in HIV/AIDS patients and there are at least 15 FDA-approved antiretroviral products that contain either TDF or TAF. However, due to their hydrophilic nature, low permeability, and premature hydrolysis or activation, TDF and TAF both have a considerably low oral bioavailability of 25% and 40% respectively. Given that these drugs need to be administered for the lifetime of HIV patients, strategies to improve oral bioavailability leading to optimal drug utilization and reduced therapeutic dose need to be developed. Transformation of ionizable, highly hydrophilic or hydrophobic drugs into ionic liquids (ILs), low- melting organic salts with a melting point < 100°C, has emerged as a novel and pharmaceutically viable approach to improving pharmaceutical processability, solubility, permeability, and oral bioavailability of drugs. Our preliminary data show that it is possible to transform ionizable hydrophobic drugs such as anthelmintic benzimidazoles, and hydrophilic ionizable drugs such as metformin hydrochloride into low-melting ILs using pharmaceutically acceptable fatty anion such as sodium docusate. Our preliminary further show that the developed ILs can be efficiently packaged into polymeric nanomicelles further leading to improved oral delivery and in vivo efficacy. Hence, we hypothesize that the transformation of TDF and TAF into amphiphilic ionic liquids (ILs) using generally regarded as safe (GRAS) fatty permeation enhancers and their subsequent incorporation into polymeric nanomicelles will improve oral bioavailability and in vivo antiviral efficacy. Our preliminary data show that TDF and TAF can be rapidly and efficiently converted to amphiphilic ILs using GRAS fatty permeation enhancers such as decanoic acid, undecylenic acid, oleic acid, and salcaprozic acid. Aim 1 will focus on the development, characterization, and pharmacokinetic evaluation of polymeric nanomicelles containing TDF-ILs or TAF ILs. Aim 2 will focus on the in vivo antiviral efficacy evaluation of oral polymeric nanomicelles containing TDF IL in humanized BLT mouse model of HIV infection compared to pure TDF or TAF to establish the proof of concept. The successful completion of this proposal is expected to lead to the development of clinically viable pharmaceutical formulations containing ILs of tenofovir prodrugs to achieve effective long-term management of HIV infection.