Bioavailability of a new effervescent tablet of diclofenac.
OBJECTIVE
The bioavailability of a newly developed effervescent tablet containing 50 mg diclofenac Na (DIC-effervesc) was investigated and compared with an enteric-coated dragée (DIC-enteric).


METHODS
24 healthy, male and informed volunteers (mean body weight 78.8 kg, mean age 31.9 years) received in a randomized cross-over design a single dose of 50 mg diclofenac as DIC-effervesc and DIC-enteric. A total of 19 blood samples were obtained before and up to 12 h after administration according to the different properties of the galenic formulation. Diclofenac was analyzed by a sensitive HPLC method with a lower limit of quantification of 20 ng/ml. The bioavailability was compared as ratios of the geometric means of AUC0-infinity and Cmax.


RESULTS
DIC-effervesc shows no lag time, a tmax within 30 min and a double peak of Cmax in 15/24 subjects. The mean Cmax (arithm. mean +/- SD) for DIC-effervesc is 950+/-341 ng/ml (first Cmax) and for DIC-enteric 1364+/-335 ng/ml. The mean AUC0-infinity, (arithm. mean +/- SD) amounts to 1097+/-210 ng/ml x h for DIC-effervesc and 1262+/-220 ng/ml x h for DIC-enteric. Based on the point estimator and the 90% interval DIC-effervesc is bioequivalent in respect to amount absorbed (86.4%; 81.8 - 91.3%). DIC-effervesc was well tolerated.


CONCLUSIONS
The new effervescent tablet of diclofenac Na shows a rapid absorption without lag time, the same amount of absorption and a slightly lower Cmax (caused by a double peak phenomenon) in comparison to the enteric-coated dragee. A rapid onset of therapeutic effect is postulated in acute pain disorders.
Terhaag
B
B
Corporate Research and Development, ASTA Medica Group, Arzneimittelwerk Dresden, Germany.
Hoffmann
A
A
Barkworth
M
M
Vens-Cappell
B
B
D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000493:pharmacokinetics*; D001682:Biological Availability; D018592:Cross-Over Studies; D004008:Diclofenac / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D013607:Tablets
D000894:Anti-Inflammatory Agents, Non-Steroidal; D013607:Tablets; D004008:Diclofenac