The pharmacokinetic factors and bioavailability of rifampicin, isoniazid and pyrazinamid fixed in one dose capsule.Acta Pol Pharm. 2002 Nov-Dec; 59(6):448-52.AP
A study was performed at the National Tuberculosis and Lung Diseases Research Institute (NTLDRI) in Warsaw according to the protocol by the Ethics Committee of the Institute. The main target of the mentioned study was a comparison of the bioavailability of rifampicin. isoniazid and pyrazinamid fixed together in one capsule with the bioavailability of the same doses of these drugs, which were given separately. The absorption of rifampicin, isoniazid and pyrazinamid were tested after oral administration of each drug in free simultaneous combinations and in a fixed-dose combination of three drugs--Trifazid. The study was carried out as an open randomised crossover experiment comprising 16 volunteers. The results have shown that the pattern of absorption, plasma concentrations and pharmacokinetic parameters were found to be very similar after administration of the drugs in free and fixed combinations. The triple combination of antituberculosis drugs could replace the separate drugs in the treatment of tuberculosis.