Release kinetics of drug from different combined ratios of micropellets.

Release behaviours of different combined ratios of fast-release (FR) and sustained-release (SR) micropellets were studied. The release kinetic of the combined ratios of theophylline micropellets system was found to be a Higuchi matrix release model, and a linear regression was found between the release rate and the combined ratio of FR and SR theophylline micropellets. However, the combined ratio of the indomethacin micropellets system was found to be an apparent zero-order release kinetic and a quadratic regression was obtained between the zero-order release rate and the combined ratios of FR and SR indomethacin micropellets. This different release behaviour might be due to the different type and concentration of coating solution used.