Department of Pharmacology and Toxicology, University of Nairobi, Kenya. The relative bioavailabilities of three carbamazepine tablet formulations available in the Kenyan market (Temporal(R), Taver(R) and Carbamazepine Lincoln) compared with the innovator formulation (Tegretol(R)) were evaluated in seven healthy African volunteers (5 males, two females; aged 22-36 years), according to a randomised fourway crossover study design, following oral administration of single 200 mg doses with a three week washout period. In vitro dissolution profiles of the tablets were also evaluated. Relative bioavailabilities ((F)rel) of Temporal(R), Taver(R) and Carbamazepine Linocoln were 101.2%, 82.2% and 71.6% respectively, compared with Tegretol(R). Percent drug content dissolved in vitro after I hour were 91.3%, 75.9% and 39.3% for Temporal(R), Taver(R) and Carbamazepine Lincoln, respectively. It was concluded that Temporal(R) was bioequivalent to Tegretol(R) while Taver(R) and Carbamazepin Lincoln were bioinequivalent to Tegretol(R). Administration of Taver(R) or Carbamazepine Lincoln might lead to poor control of epileptic seizures.