Antiparasitic Drug Treatment in Mice

For drug treatment, benznidazole (Hoffmann-La Roche AG) was prepared from powder at 10 mg/ml in 7% Tween 80, 3% ethanol (vol/vol), and 90% (vol/vol) water. Posaconazole (Sequoia Research Products, Ltd.) was prepared at 2 mg/ml in 5% (vol/vol) dimethyl sulfoxide and 95% (vol/vol) HPMC-SV (0.5% [wt/vol] hydroxypropyl methylcellulose, 0.5% [vol/vol] benzyl alcohol and 0.4% [vol/vol] Tween 80). Noxafil (MSD, Ltd.), a liquid formulation of posaconazole (40 mg/ml), was diluted to 2 mg/ml in water. Mice were treated with standard doses of benznidazole (100 mg/kg/day) or posaconazole (20 mg/kg/day) by oral gavage for consecutive days, as required. To facilitate the detection of residual infection after treatment, BALB/c mice were immunosuppressed in some experiments with cyclophosphamide (200 mg/kg) by i.p. injection at 3- to 4-day intervals, for a maximum of three doses.