Control of the particle properties of a drug substance by crystallization engineering and the effect on drug product formulation

A study of the process−property−performance relationship of a Bristol-Myers Squibb drug substance led to successful development of crystallization and drying processes that produce crystals with desired and consistent physical properties. A controlled crystallization technique was developed to obtain well-defined, large crystals with a narrow particle size distribution. This crystallization process provided a less compressible filter cake for effective cake washing and deliquoring and afforded an easily dried product with desired powder properties. To preserve the quality of the crystals during drying, a drying protocol using low shear agitation was developed. This protocol prevented crystal attrition during drying, which was shown to adversely affect the formulation process and, thus, drug product performance. API crystals prepared by this method consistently resulted in excellent formulation processing and drug product performance.