RELEASE KINETICS OF DRUG FROM DIFFERENT COMBINED RATIOS OF MICROPELLETS

Release behaviours of different combined ratios of fast-release (FR) a nd sustained-release (SR) micropellets were studied. The release kinet ic of the combined ratios of theophylline micropellets system was foun d to be a Higuchi matrix release model, and a linear regression was fo und between the release rate and the combined ratio of FR and SR theop hylline micropellets. However, the combined ratio of the indomethacin micropellets system was found to be an apparent zero-order release kin etic and a quadratic regression was obtained between the zero-order re lease rate and the combined ratios of FR and SR indomethacin micropell ets. This different release behaviour might be due to the different ty pe and concentration of coating solution used.