BIOAVAILABILITY AND PHARMACOKINETICS OF FLUORIDE FROM 2 GLUTAMINE MONOFLUOROPHOSPHATE PREPARATIONS

A two-way cross-over study was conducted on 12 Caucasian male healthy volunteers aged between 25 and 38 years in order to determine the bioa vailability and pharmacokinetics of fluoride after single oral adminis tration in fasting conditions of two products (tablets and powder for oral use) of L-glutamine monofluorophosphate (G-MFP CAS 116420-36-1). The two products contained the equivalent of 10 mg F and the equivalen t of 300 mg CA as calcium gluconate and calcium citrate. The two produ cts were found bioequivalent with regard to the release of fluoride, b oth on the basis of the AUC and C(max) of fluoride in plasma and of th e urinary excretion of fluoride during the 48 h following the administ ration. The pharmacokinetics of fluoride in plasma is characterized by a short lag time (< 6 min), a rapid absorption, a peak which is reach ed 0.5-1.0 h after administration, followed by a biphasic elimination. The first phase with a k(alpha) of 1.8 h-1 is followed by a slower ph ase with a K(beta) of 0.14 h-1. Probably the terminal elimination rate is slower, about 0.05 h-1. The urinary excretion of fluoride during t he 48 h after administration accounted for 40-50% of the administered dose of fluoride. The results are consistent with those found in previ ous studies after administration in fasting conditions of sodium fluor ide or sodium monofluorophosphate alone or in combination with calcium salts.