Comparative bioavailability of three different preparations of rifampicin

J Clin Pharm Ther. 1999 Jun;24(3):219-25. doi: 10.1046/j.1365-2710.1999.00223.x.


Objective: To study the relative bioavailabilities of two generic rifampicin preparations with Rimactane.

Method: Each of nineteen healthy volunteers received a single oral dose of 600 mg of rifampicin in an open cross-over randomised three-way single-dose design with a washout period of 7 days between each doses. Plasma concentrations of rifampicin were determined by HPLC. In vitro dissolution profiles of the same drugs were determined and compared with human bioavailability study results.

Results: No statistically significant difference was found in main bioavailability parameters between Rimactane and generic preparations studied. Both generic preparations also fulfilled the bioequivalence criteria based on the 90% confidence intervals. There was a good correlation between in vivo and in vitro results: faster dissolution time corresponded to the lower Tmax value; lower percentage of released compound to the lower AUC value. Significant intersubject variations were found in main bioavailability parameters; significant negative correlation was found between average AUC values and body weight of the volunteer.

Conclusion: All three products were bioequivalent. Our results also suggest the suitability of one-compartmental model with lag time, first order input and first order output to describe the kinetics of rifampicin.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Antibiotics, Antitubercular / administration & dosage
  • Antibiotics, Antitubercular / pharmacokinetics*
  • Biological Availability
  • Chemistry, Pharmaceutical
  • Cross-Over Studies
  • Female
  • Humans
  • Kinetics
  • Male
  • Rifampin / administration & dosage
  • Rifampin / pharmacokinetics*
  • Therapeutic Equivalency


  • Antibiotics, Antitubercular
  • Rifampin