Abstract
Microencapsulation of indomethacin (mc-IM) was carried out by using a gelatin. Sustained-release suppositories containing only mc-IM, and containing both mc-IM and intact IM were prepared by the fusion method. Plasma concentrations after rectal administration of the sustained-release suppository containing only mc-IM reached a plateau level and did not rise above 5μg/ml. No difference in bioavailability could be seen between this sustained-release suppository and the conventional suppository. The sustained-release suppository prepared by mixing mc-IM with intact IM rapidly gave a desirable plasma concentration and maintained an effective plasma level of the drug for a considerable period of time, that is, the maximal plasma concentration (Cmax) was below 5μg/ml and the time for which a plasma level above 2μg/ml was maintained was 6h. On the basis of these results, the combined dosage form should represent a convenient therapy with reduced risk of side-effects and reduced frequency of administration.
