DOSE RELEASED AND ABSOLUTE BIOAVAILABILITY OF NICOTINE FROM A NICOTINE VAPOR INHALER

In an open, randomized, three-way crossover study, 14 healthy smokers used one type of nicotine vapor inhaler intensely for 20 minutes every hour for 11 hours (12 administrations). Two different inhalation tech niques were applied, shallow frequent sucking (buccal mode) and deep i nhalations (pulmonary mode), liquid extraction of the plasma sample, N icotine was detected by means of a nitrogen-sensitive detector, giving high selectivity and sensitivity. The mean (+/-SD) nicotine dose rele ased from each nicotine vapor inhaler unit was estimated at 4.00 +/- 0 .60 mg (buccal mode) and 3.87 +/- 0.75 mg (pulmonary mode), inhaled wi th approximately 15 L of air, Mean (+/-SD) peak plasma level of the la st dosing interval was 32.0 +/- 8.7 ng/ml and 34.2 +/- 8.9 ng/ml for t he buccal and the pulmonary technique, respectively, achieved after 0. 33 and 0.50 (median) hour, respectively. The mean (95% confidence inte rval [CI]) absolute bioavailability of nicotine was 51 (95% CI, 40 to 65) and 56 (95% CI, 47 to 67) when the buccal and pulmonary techniques mere used, respectively, A significant correlation was found between systemically available dose and average steady state nicotine plasma c oncentration, Based on the achievement of similar nicotine plasma leve ls, it may be concluded that the two modes of inhalation appear to be clinically equivalent.