Effect of dosage form on stereoisomeric inversion of ibuprofen in volunteers

Tetsuya Aiba, Mary M. Tse, Emil T. Lin, Tamotsu Koizumi

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Twelve healthy volunteers were given ibuprofen racemate in two different dosage forms, a suspension and a tablet. The plasma concentration-time profiles of S- and R-ibuprofen were determined and the R-ibuprofen inversion clearance was calculated. Although the area under the curve was almost the same in both the suspension and tablet studies, the inversion clearance was larger in the suspension study than in the tablet study (1.18±0.65 and 0.72±0.63 l/h, shown as the mean±S.D.). The Michaelis-Menten parameters for this inversion process were then determined in vitro with human liver microsomes (1.3±0.2 mM for K(m) and 3.1±0.3 nmol/min/mg protein for V(max), shown as the mean±S.D.). These parameters indicated that the stereoisomeric inversion of R-ibuprofen in the liver was not likely to be saturated at the plasma concentrations measured in the volunteer study. The profile of the plasma concentration ratio between S-ibuprofen and R-ibuprofen revealed a difference in the early phase of these two studies. Therefore the inversion difference between those two studies probably resulted from the difference in the absorption phase of each dosage form. Our study demonstrated that R- ibuprofen inversion could be affected by alteration of dosage form.

Original languageEnglish
Pages (from-to)616-622
Number of pages7
JournalBiological and Pharmaceutical Bulletin
Volume22
Issue number6
Publication statusPublished - 1999
Externally publishedYes

Fingerprint

Ibuprofen
Dosage Forms
Volunteers
Tablets
Suspensions
Liver Microsomes
Area Under Curve
Healthy Volunteers
Liver

Keywords

  • Dosage form
  • Healthy volunteer
  • Human liver microsome
  • Ibuprofen
  • Stereospecific inversion

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmacology, Toxicology and Pharmaceutics(all)

Cite this

Effect of dosage form on stereoisomeric inversion of ibuprofen in volunteers. / Aiba, Tetsuya; Tse, Mary M.; Lin, Emil T.; Koizumi, Tamotsu.

In: Biological and Pharmaceutical Bulletin, Vol. 22, No. 6, 1999, p. 616-622.

Research output: Contribution to journalArticle

Aiba, Tetsuya ; Tse, Mary M. ; Lin, Emil T. ; Koizumi, Tamotsu. / Effect of dosage form on stereoisomeric inversion of ibuprofen in volunteers. In: Biological and Pharmaceutical Bulletin. 1999 ; Vol. 22, No. 6. pp. 616-622.
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