Acta Pharm. 62 (2012) 1-14

full paper

Review

Spherical crystallization of drugs

BORUT KOVAČIČ, FRANC VREČER and ODON PLANINŠEK

odon.planinsek@ffa.uni-lj.si

¹ Krka d. d., Šmarješka cesta 6, 8501 Novo mesto, Slovenia

² University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000 Ljubljana, Slovenia

Accepted March 02, 2012

Spherical crystallization of drugs is the process of obtaining larger particles by agglomeration during crystallization. The most common techniques used to obtain such particles are spherical agglomeration and quasi-emulsion solvent diffusion. Ammonia diffusion systems and crystallo-co-agglomeration are extensions of these techniques. By controlling process parameters during crystallization, such as temperature, stirring rate, type and amount of solvents, or excipient selection, it is possible to control the formation of agglomerates and obtain spherical particles of the desired size, porosity, or hardness. Researchers have reported that the particles produced have improved micromeritic, physical, and mechanical properties, which make them suitable for direct compression. In some cases, when additional excipients are incorporated during spherical crystallization, biopharmaceutical parameters including the bioavailability of drugs can also be tailored.

Keywords: spherical crystallization, agglomeration, solvent diffusion, improved particle properties