S.E. Leucuta *, R. Capalneanu, A. Bodea, Marcela Achim, Ana Rusu, Mirela Moldovan, D.I. Postescu
* Prof. S.E. Leucuța and colab. – University of Medicine and Pharmacy “Iuliu Hatieganu”, Cluj Napoca, Department of Biopharmaceutics and Pharmacokinetics Biopharmacy and Phannacokinetics Laboratory
Abstract
The aim of the present study was to compare two different formulations of diclofenac potasium tablets (50 mg): Diclofenac K (Jordan Chemical Laboratory) and Cataflam (Geigy). This open study included 12 male volunteers aged between 22 and 28 years, all of whom provided written informed consent prior to enrolment. Ethical approval for the study was obtained from the university Ethical Commitee. Volunteers received an oral dose of diclofenac potasium (50 mg) inan open, randomised, 2-way cross over study with a washout period of 7 days between treatment periods. Diclofenac was assayed by the use of a validated reversed-phase HPLC with U.V. detection. Pharmacokinetic parameters were evaluated according to standard methods: area under the curve (AUC), maximum plasma concentration,(Cmax), time of the maximum, (Tmax), biological half-time. They were evaluated by analysis of variance (ANOVA) and by bioequivalence methodology, after log transformation for AUC and Cmax and by the difference of nontransformed mean values for Tmax. To test the bioequivalence of the two formulations, standard confidence interval, symetrical confidence interval according to Westlake and the two one sided+test (Schuirman test) were calculated. The non parametric test was used for Tmax analysis. The calculated values for AUC, Cmax and Tmax were in the bioequivalence range (0,8 – 1,25). Based on the pharmacokinetic parameters evaluated in this study, it was concluded that Diclofenac K (Jordan Chemical Laboratory) formulation is bioequivalent to Cataflam (Geigy) tablets, both as amount and rate of absorption. They may actually be effective as a maintenance treatment for antiinflammatory disorders.