A Bioequivalence Study of Two Oral Desmopressin Tablet Formulations

The present study was carried out to test bioequivalence between two different oral desmopressin formulations. Sixty healthy volunteers were enrolled in the study and were randomly assigned to receive the test (T) and reference (R) drug in a two-period two-sequence, crossover, analyst-blinded study design. Subjects received an oral dose of 400 µg of desmopressin acetate separated by a wash-out period of at least 7 days. The area under the concentration-time curve (AUC) over 12 h in plasma and the maximum concentration (C_max) were compared by analysis of variance (ANOVA) after log transformation. The mean ratios of the T to R drug were within the bioequivalence boundaries with mean values of 1.00 (90% CI: 0.87–1.14) and 1.03 (90% CI: 0.92–1.15) for AUC_0–t and AUC_0–inf, respectively. For the C_max, the mean ratio of the T to R drug was 0.97 (90% CI: 0.87–1.08). The rate and the extent of oral desmopressin absorption were identical for both formulations. Hence, the desmopressin test tablet met all bioequivalence criteria of the marketed reference desmopressin tablet.