Abstract
The release rates of indomethacin from 5 kinds of commercially available suppositories were compared by using three different methods, i.e., dialysis cell, membrane diffusion, and cylindrical filter paper.The release from each fatty base by the method of membrane diffusion was about 30% for labeled amount after 120min, and that from each macrogol base was 23%.By dialysis cell method, indomethacin released from macrogol base was about 80% after 120min, whereas that from fatty base was 26-37%. The maximum plasma concentrations of indomethacin after rectal administration of both products A and B composed of macrogol base to rabbits was 31.8μg/ml, and those of products C, D, and E of fatty base were 21.4, 15.0, and 34.7μg/ml, respectively.The in vitro release rate was not concerned in the plasma concentration of indomethacin.It was found that the volume of suppository markedly influenced the rectal absorption, because correlation coefficient between the maximum plasma concentration of indomethacin and the volume of suppository was 0.932.
