Comparative bioavailability of three benznidazole formulations in healthy individuals: a randomised study

BACKGROUND Benznidazole (BZN) has been used for more than fifty years in the treatment of Chagas disease (CD). It is produced by only three pharmaceutical companies worldwide: Lafepe (Brazil); Elea (Argentina) and Liconsa (Spain). The therapeutic interchangeability among these products has never been evaluated. OBJECTIVES To assess bioequivalence between three 100 mg BZN formulations. METHODS Pharmaceutical equivalence, with dissolution testing, was assessed prior to the bioequivalence study. For bioequivalence, healthy adult participants received 100 mg of BZN formulations after meal, in a randomised clinical trial. Blood BZN concentrations were measured. Pharmacokinetic parameters were determined by non-compartmental analysis. FINDINGS The BZN Liconsa demonstrated faster in vitro dissolution. However, bioavailability was not different between formulations. The mean area under the curve (AUC)84h values were 49431.22 h*ng/mL (SD = 9938.53) to Lafepe, 48974.38 h*ng/mL (SD = 10304.67) to Elea and 48204.17 h*ng/mL (SD = 9342.18) to Liconsa. The mean Cmax values were 2339.23 ng/mL (SD = 445.53) for Lafepe, 2209.04 ng/mL (SD = 448.02) for Elea and 2303.90 ng/mL (SD = 431.41) for Liconsa. The mean tmax was not different between formulations. AUC were higher in women for Elea (20%) and Lafepe (27%). The adverse events did not differ between sexes. MAIN CONCLUSIONS The 100 mg BZN formulations demonstrated bioequivalence.