Improved oral bioavailability of anti-HIV agent N'-[2-(2-thiophene)ethyl]-N'-[2-(5-bromopyridyl)]-thiourea (HI-443) in a novel lipophilic formulation.

N'-[2-(2-Thiophene)ethyl]-N'-[2-(5-bromopyridyl)]-thiourea (CAS 258340-15-7, HI-443) is a rationally designed non-nucleoside reverse transcriptase inhibitor (NNRTI) with potent anti-HIV activity at nanomolar concentrations but poor oral bioavailability. Here the identification of a novel oleic acid containing lead formulation of HI-443 is described which resulted in a approximately 10-fold improvement of its oral bioavailability yielding 10-fold higher systemic exposure levels in mice. Formulated HI-443 exhibited a favorable pharmacokinetics and toxicity profile in mice.