Dissolution and Precipitation Monitoring of Crystalline Salts

Purpose. Formation of an API (active pharmaceutical ingredient) salt is a common technique for improving the dissolution characteristics and supersaturation of a poorly soluble drug. The supersaturated solution may then precipitate as the free acid or base. The aim of this study was to evaluate the practicality of combining real-time concentration monitoring with fiber optic spectroscopy and powder x-ray diffraction (PXRD) to provide an assessment of salt disproportionation and precipitation.

Conclusions. Combining real time in situ monitoring with solid state characterization can provide the preformulation or formulation scientist with a more complete understanding of processes that may suggest drug formulation and development strategies to improve the oral absorption window for a poorly soluble AP.