ABSTRACT

Pharmaceutical particulates may be produced by constructive and destructive methods. Particle constructive methods include crystallization; spray-drying; freezedrying; and supercritical fluid techniques. Crystallization is the most common method of particle production. The solid crystalline state is produced from a liquid solution by cooling, evaporation, precipitation, or the addition of another compound. Spray-drying is a process by which a dried particulate form is produced by spraying a liquid into a hot drying medium. It involves atomization of the liquid feed into fine droplets, evaporation of the solvent, and size separation of dried particles from the drying medium. Particle generation using supercritical fluids provides recrystallization by precipitation. Particles are produced by a variety of methods. Crystallization occurs from saturated solutions or hot melts to form solids. Particle morphology is a fundamental element in suspension and powder behavior. An understanding of the principles of particle formation and manufacturing process controls is essential in the optimization of product performance.