Aims: The objective of this study was to determine the extent of period effect on the pharmacokinetics of cyclosporin A (CsA) during consecutive dosing.
Methods: Sandimmune Neoral and Neoplanta capsules were administered to twenty-four healthy Korean male subjects at a single CsA dose of 175 mg in a 2 x 2 crossover investigation with a 2-week wash-out phase. Concentrations of CsA in blood were measured by a r.i.a. method for a period of 48 h.
Results: The two formulations were found bioequivalent, but analysis of variance (ANOVA) indicated that there is a significant (P < 0.01) period effect in AUC(0,last) (area under the blood concentration-time curve above the assay limit) and Cmax (maximum blood concentration) between the administrations. A 6 and 9% decrease in the AUC(0,last) and Cmax, respectively was seen at the second administration.
Conclusions: This period effect on the pharmacokinetics of CsA may be relevant for the patients who need consecutive administration of the drug.