Bioequivalence assessment of closerin capsule to dura seromycin capsule of cycloserine after a single oral dose administration to healthy male volunteers.

Aim: A bioequivalence study of the closerin capsules to the dura seromycin capsules was conducted. Patients and methods: Twenty-four healthy male Korean volunteers received each medicine at the cycloserine dose of 250 mg in a 2 × 2 crossover study. There was a one-week washout period between the doses. Plasma concentrations of cycloserine were monitored by a high-performance liquid chromatography for over a period of 72 hours after the administration. AUC inf (the area under the plasma concentration-time curve from time zero to time infinity) was calculated by the linear-log trapezoidal method. C max (maximum plasma drug concentration) and T max (time to reach C max ) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC inf and C max , and untransformed T max . Results: There were no significant differences between the medications in AUC inf and C max . The point estimates and 90% confidence intervals for AUC inf (parametric) and C max (parametric) were, in point estimate (90% confidence interval), 0.992 (0.950 1.037) and 1.051 (0.965 ∼ 1.144), respectively, satisfying the bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration Guidelines. The corresponding value of T max was 0.000 (-0.250 ∼ 0.125). Moreover, the modified Pitman-Morgan's adjusted F test and equal variance test (one-sided) indicated that the 2 medications were comparable in intra- and inter-individual variability in cycloserine bioavailability. Conclusion: Therefore, these results indicate that the 2 medications of cycloserine are bioequivalent and, thus, may be prescribed interchangeably.