Comparison of the bioavailability of dexibuprofen administered alone or as part of racemic ibuprofen

Abstract

Two bioavailability studies of S(+)-ibuprofen (dexibuprofen) were conducted in healthy volunteers to define the relationship between the bioavailability 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 dexibuprofen from a 400 mg tablet formulation was compared with that from 400 mg in aqueous solution. The tablet formulation did not influence the bioavailability of the drug and dexibuprofen was well absorbed from the gastro-intestinal tract. The second study was divided into three identical parts. Bioavailability of dexibuprofen 200, 400 and 600 mg was compared with its bioavailability from ibuprofen racemate 400, 800 and 1200 mg. The second study showed that the mean relative bioavailability of dexibuprofen to ibuprofen racemate was 0.66, thus enabling the estimation of clinically useful dexibuprofen doses from the usual doses 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 therapeutically active drug.

The effects and safety of dexibuprofen compared with ibuprofen in febrile children caused by upper respiratory tract infection

“…Ibuprofen exists in equal amounts of racemic mixture of S(+) and R(–) enantiomers [20, 21]. Dexibuprofen is the S(+) (dextrorotatory)‐enantiomer of ibuprofen and accounts for virtual pharmacodynamic activities of the racemic compound [21–24].…”

Perioperative pharmacokinetics of ibuprofen enantiomers after rectal administration

“…As stated earlier, (R)‐(−)‐ibuprofen undergoes a unidirectional metabolic inversion to (S)‐(+)‐ibuprofen. Previous studies have reported that the ratio of (S)‐(+)‐ibuprofen AUC to that of (R)‐(−)‐ibuprofen varies between 1.6 and 2.09 (23,24). The inversion is reduced in patients suffering from pain after dental surgery (25).…”

Dexibuprofen for fever in children with upper respiratory tract infection

“…Furthermore, the bioavailability of S(+) ibuprofen given alone was found to be 92% in a study by Cheng et al . In one of the few bioavailability comparison studies, the mean relative bioavailability of dexibuprofen to ibuprofen was 0.66 . For these reasons, 5 mg (DEX 1) and 7 mg (DEX 2) were chosen as maximum dexibuprofen doses.…”