Selective Crystallization Of A Novel Polymorph

By Sarah Bethune, PhD, Sr. Director, Pharmaceutics & Formulation Development, and Terry J. Harper, Director, Material Characterization, Cambrex

When success in early trials creates a demand for new batches of API, the emergence of an unexpected polymorph can be a major setback to meeting critical clinical timelines.

Different polymorphs of the same API can exhibit different physical properties including stability, solubility, and bioavailability in the body. Isolating the stable polymorph reliably in each batch is vital to the success of API manufacturing and formulation. Ideally, the optimal polymorph is selected early in development to steer formulation strategies. However, it’s not uncommon for a new polymorph to arise after API manufacturing is underway.

Here’s a look at how Cambrex applied rigorous characterization standards and expert knowledge of critical water activity to isolate a previously undiscovered and uncharacterized polymorph. At the same time, they were challenged with supplying the original polymorph to maintain batch production in order to meet a critical need for an ongoing clinical trial.