Solventless Drug Pelletization and Polymer Coating Techniques for Pharmaceutical Manufacturing

Abstract

This paper described a review of solventless drug pelletization and polymer coating techniques using a mechanical powder processor as well as conventional processors including a high shear granulator and a V-shaped blender. Mechanical powder processing of drug crystals provided pellets comprising drug alone and the pelletization was due to inherent adhesiveness of drug powder as well as mechanically-induced dehydration or amorphization of drug crystals. Mechanical powder coating of polymethacrylates and ethylcellulose was achieved using freeze dried powder comprising colloidal polymer particles. High shear mixing of drug crystals and cellulose spheres provided drug-layered pellets by ball-milling actions of the spheres in the granulator. V-shaped blending of uncoated tablets and colloidal polymer powder resulted in the coating of the tablets with broken polymer particles. These techniques include only simple mixing processes and need no solvents, thereby contributing to the reduction of the environment impacts and costs in pharmaceutical manufacturing.