THE PHARMACOKINETICS AND RELATIVE BIOAVAILABILITY OF FLAVOXATE CAPSULES IN HEALTHY VOLUNTEERS

The pharmacokinetics and relative bioavailability of flavoxate (FL) capsules was studied in 10 healthy male volunteers. A single oral dose 200 mg FL of reference(tablet) or test(capsules) drugs was given to each volunteer according to an open randomized crossover design. The concentration of 3-methylflavone-8-carboxylic acid(MFCA), a main active metabolite of FL , was determined by HPLC method. The main pharmacokinetic parameters of MFCA were: AUC0→∞ 33.87±4.97 (mg·h·L-1) and 35.98±6.92 (mg·h·L-1),Tmax 0.92±0.23 h and 0.83±0.35 h, Cmax 12.98±2.63 mg·L-1 and 13.95±2.78 mg·L-1 for tablet and capsules respectively. The results of statistical analysis showed that two formulations were bioequivalent.