Abstract
Coprecipitates and physical mixtures of indomethacin (IM), lactose and mastic were studied to determine the effect of mastic on drug dissolution rate, bioavailability and ulcerogenic effects in rats. The drug was received as oral suspensions of IM preparations containing 20 mg/kg. The mean particle diameter of the coprecipitate was increased with increase of mastic concentration. The X-ray diffraction pattern showed a crystalline IM in the coprecipitate. The drug release rate in phosphate buffer (pH 7.2) was improved by the addition of polysorbate-80 to the release media. The presence of mastic retarded drug dissolution rate. This retardation was dependent on the percentage of mastic in the preparation as well as the method of preparation. The results of bioavailability showed a sustained effect of drug from IM-mastic physical mixture and coprecipitate. The ulcerogenic activity of IM was reduced in all the preparations containing mastic as compared with that containing IM alone.