Subcutaneous biodegradable reservoir device

A reservoir device comprising an active agent formulation contained within a reservoir, the reservoir defined by a biodegradable, permeable polymer membrane having a thickness of 100 μm to 300 μm, wherein the active agent formulation comprises an active agent and an excipient, wherein the excipient includes castor oil, wherein a mass ratio of active agent to excipient in the reservoir ranges from 1:1 to 3:1, wherein the active agent dissolves in the excipient to form an active agent solution, wherein a formation rate of the active agent solution is greater than a diffusion rate of the active agent solution through the polymer membrane, wherein the polymer membrane comprises polycaprolactone (PCL) at a molecular weight ranging from 15,000-140,000 Da, the polymer membrane allowing for diffusion of the active agent solution there through when positioned subcutaneously in a body of a subject, wherein the reservoir device is configured for an average release rate of the active agent ranging from 15 to 30 μg/day;

• and wherein the active agent comprises tenofovir alafenamide fumarate (TAF), 4′-ethynyl-2-fluoro-2′-deoxyadenosine (EFdA), levonorgestrel (LNG);
• etonogestrel (ENG), emtricitabine (FTC), tenofovir (TFV), tenofovir disoproxil fumarate (TDF), EFdA-alafenamide, bictegravir (BIC), tamoxifen citrate, naltrexone or combinations thereof.