[Biotransformation and bioequivalence of a new nifedipine preparation]

Following a single dose of two 5 mg soft gelatine capsules with nifedipine (Pidilat as a test preparation and a commercially available reference preparation) to 12 healthy volunteers in a randomized, 2-fold cross-over trial (latin square), blood samples were drawn up to 16 h post application (p.a.). The nifedipine plasma levels were quantitatively determined by a capillary gas chromatographic assay. Some important pharmacokinetic parameters as well as the bioavailability/bioequivalence were evaluated and subsequently compared for possible statistically significant differences between the preparations. Approximately 0.5 h p.a. mean peak plasma concentrations of about 110-120 ng/ml were reached; the mean terminal half-live was 1.5 h. The plasma level-time curves were-except for the negligible different peak concentrations-virtually identical; thus both preparations are considered to be bioequivalent.