Effects of different manufacturing methods on pharmaceutical properties and release kinetic models of ketoprofen sustained-release microparticles

Extrusion-spheronization and the fluid bed method are valuable commonly applied methods in microparticle production. However, the characteristics of resultants prepared by these two methods have seldom been compared. The aim of this study was to investigate differences in pharmaceutical properties and release kinetics of sustained-release ketoprofen microparticles prepared by different manufacturing processes. Microparticles prepared by extrusion-spheronization displayed slower release rate resulting in increased diffusion path of the drug, a behavior distinct for microparticles with less Surelease®. The effects of manufacturing method on release rate was also significant for microparticles with less Surelease®compared to microparticles with more Surelease®. The release profiles of coated microparticles fitted well to the Higuchi’s release model, but in cases of microparticles with larger Surelease® coating, the trend was towards a zero-order release model. These findings are valuable for comprehending the differences among different preparation processes and for choosing the optimal manufacturing method of sustained-release microparticles.   Key words: Ketoprofen, microparticles, sustained drug delivery, extrusion-spheronization, fluid-bed, dissolution release kinetics.