[Pharmacokinetics of a fluoride-calcium preparation for the treatment of osteoporosis].

The pharmacokinetics of fluoride and calcium were studied after administration of a combined fluoride and calcium preparation (Tridin) (1, 2 and 3 tablets) in 9 healthy male volunteers, using a cross-over study design. The total estimation of the pharmacokinetic data was performed by a simultaneous curve fitting to all single values, using a direct search procedure based on an open two-compartment model and three-compartment model, respectively. Maximum plasma concentrations and areas under the curve are proportional to the dose administered. Inter-subject variations are comparatively small, computerized multiple dose simulation for 3 days does not show any cumulation. The data fit the two-compartment model and the three-compartment model as well. The behaviour of the calcium concentrations reflects the immediate response of calcium homeostasis: plasma calcium concentrations are not affected.