FOERFARANDE FOER FRAMSTAELLNING AV ETT SOETNINGSSYSTEM.

摘要

The present invention pertains to a method for preparing a stable delivery system comprising a core material coated with a coating layer material which is a combination of an emulsifier and a low molecular weight polyvinyl acetate, which method comprises the steps of: (a) melting and blending the emulsifier and polyvinyl acetate; (b) mixing the core material with the coating layer material of step (a); (c) carrying out a crude granulation on the mixture of step (b) at an elevated temperature in the range of 60 DEG to 75 DEG C; (d) carrying out a fine granulation to the desired particle size on the crude granulation of step (c) at a relatively lower temperature. Step (a) is preferably carried out in a heated mixing bowl. The mixing of step (b) is preferably carried out in a double planetary mixer preferably connected via a discharge valve to the bowl used for step (a). Step (c) is preferably carried out in a hot melt granulator. Step (d) is preferably carried out in an oscillating granulator. The mixture of step (c) may be cooled by being passed through a cyclone prior to step (d). Step (d) is preferably carried out at a temperature in the range of 20 to 35 DEG C.