Approaches to Drying Hydrated Active Pharmaceutical Ingredients (APIs).

Abstract

This project aims to develop a drying protocol that removes unwanted moisture from hydrated APIs while preserving water of hydration. Hydrate forms of model compounds, carbamazepine and theophylline, were generated with varying particle size distributions. The stability of these hydrates was examined under different conditions, and a design space for drying experiments was established.

The DVS Intrinsic was used for a small-scale drying study, providing real-time data without sample disruption. The effects of temperature, %RH, PSD, and hold times on drying and hydrate stability were investigated. Non-ambient XRPD experiments provided insights into transitions during drying and dehydration.

Based on the data, a convective oven with a predictive drying model was developed. The model allowed predicting drying times for each hydrate form. Overall, the study demonstrates the feasibility of predicting drying times for model hydrate compounds using convective drying and the developed model.