Crystal size manipulation of acetaminophen via recrystallization

The crystal size distribution (CSD) of any material determines its end use. Consequently, comminution processes are used to transform material from one size distribution to another. Often, recrystallization from solution is one of the processes used. Recently, a novel recrystallization process named the GAS process was developed to mill compounds that were thermally labile and insoluble in supercritical fluids. CSD could be manipulated using this process. To further illustrate the applicability of this process, size manipulation studies of acetaminophen (a widely available drug) were performed. The aim of this work was to produce crystals in the mass mean size range from 5mum to 50mum, and identify the conditions for producing the desired size distribution. A modified GAS process and a liquid anti-solvent (LAS) process were also investigated. Together with acetaminophen-butanol, other systems studied were aspirin-methanol and benzoic acid-methanol