B. Gabard et al., COMPARISON OF THE BIOAVAILABILITY OF DEXIBUPROFEN ADMINISTERED ALONE OR AS PART OF RACEMIC IBUPROFEN, European Journal of Clinical Pharmacology, 48(6), 1995, pp. 505-511
Two bioavailability studies of S(+)-ibuprofen (dexibuprofen) were cond
ucted in healthy volunteers to define the relationship between the bio
availability of the drug after administration of dexibuprofen alone or
as part of ibuprofen racemate. Enantioselective plasma drug analysis
was used throughout. In the first study, the bioavailability of dexibu
profen from a 400 mg tablet formulation was compared with that from 40
0 mg in aqueous solution. The tablet formulation did not influence the
bioavailability of the drug and dexibuprofen was well absorbed from t
he gastro-intestinal tract. The second study was divided into three id
entical parts. Bioavailability of dexibuprofen 200, 400 and 600 mg was
compared with its bioavailability from ibuprofen racemate 400, 800 an
d 1200 mg. The second study showed that the mean relative bioavailabil
ity of dexibuprofen to ibuprofen racemate was 0.66, thus enabling the
estimation of clinically useful dexibuprofen doses from the usual dose
s of the racemate. The 95% confidence interval limits did not include
0.5, leading to the conclusion that administering half of the racemate
dose would not provide patients with an adequate amount of therapeuti
cally active drug.