Subject(s)
Analgesics, Non-Narcotic/therapeutic use , Anticonvulsants/therapeutic use , Antimanic Agents/therapeutic use , Carbamazepine/therapeutic use , Analgesics, Non-Narcotic/pharmacology , Analgesics, Non-Narcotic/supply & distribution , Anticonvulsants/pharmacology , Anticonvulsants/supply & distribution , Antimanic Agents/pharmacology , Antimanic Agents/supply & distribution , Carbamazepine/pharmacology , Carbamazepine/supply & distribution , Drug Monitoring/methods , Humans , Patient Education as Topic , Patient SelectionABSTRACT
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.
Subject(s)
Carbamazepine/pharmacokinetics , Carbamazepine/supply & distribution , Administration, Oral , Adult , Biological Availability , Chemistry, Pharmaceutical , Cross-Over Studies , Female , Humans , Kenya , Male , Solubility , Therapeutic EquivalencyABSTRACT
A comparative in-vitro performance of carbamazepine 200mg tablet products available on the Kenyan market was evaluated. The products which include the innovator product, Tegretol, have similar quality consonant with pharmacopoeial specifications. A batch of one of the products had a carbamazepine content of 106.6% label claim which was outside the upper limits of 105%. One product packaged in multiple-unit containers of a 1000, had an unacceptable high friability of 6.82% loss in weight. All products had good dissolution profiles and released at least 70% of the dose within 45 minutes. Drug dissolution from tablets was found to vary between batches for one product. At each sampling time, most generics had wide variations in amount of dissolved drug. The effect of such variations on tablet efficacy cannot be ascertained in the absence of bioavailability data.
