Benznidazole, was synthesized by Epichem Pty Ltd., Australia, and prepared at 10 mg/ml in an aqueous suspension vehicle containing, 5% (v/v) DMSO in 95% HPMC (0.5% (w/v) hydroxypropyl methylcellulose, 0.5% (v/v) benzyl alcohol and 0.4% (v/v) Tween 80). BenzyIMD 4a was prepared at 5 mg/ml using the same vehicle. Drugs were administered by oral gavage by weight, and vehicle only was administered to control mice.