Edwin Aret, PhD

Dr. Aret is currently the principal scientist for solid state chemistry at Alcami Corporation. He holds a PhD in solid state chemistry from Radboud University Nijmegen, Netherlands and has 15 years of experience ranging across the entire pharmaceutical development cycle, from discovery to commercialization, covering small molecules, drug substance and drug product. His expertise is on crystallization, form selection, stability studies, solubility determination, bioavailability and crystal habit optimization.

Recent Posts by Edwin Aret, PhD:

Analytics in Solid State Chemistry: What You Need to Know

Solid state chemistry is fundamental to the development of a pharmaceutical compound into a drug product, and understanding analytics is crucial to successfully addressing any challenges that can occur in a product’s lifecycle. In solid state chemistry specifically, the physical and chemical (PhysChem) analytics will show which properties need to be improved to help ensure the highest chances of success: purity, stability, solubility, or bioavailability.

In drug development, knowing the characteristics of each form of the active pharmaceutical ingredient (API) is essential in order to select the most suitable form for production. For the research chemist, the PhysChem purity is one of the most crucial requirements. Furthermore, selection of the thermodynamically most stable polymorph; low hygroscopicity measured by dynamic vapor sorption (DVS); consistent crystallinity measured using X-ray powder diffraction (XRPD); sharp single melting event determined by differential scanning calorimetry (DSC); and low levels of residual solvent by thermogravimetric analysis (TGA) are all part of the ranking criteria. Aqueous solubility and dissolution rate are indispensable for the route of delivery and dosage form.

Topics: Thought Leadership Solid State API

Crystallization in Solid State Chemistry

Solid state chemistry plays a major role in successfully developing a compound into a drug product. The physical and mechanical properties are important in selecting the most appropriate stable form with sufficient solubility. The occurrence of crystallization from a crude reaction mixture is the first step towards obtaining a pure drug substance.

For process chemists crystallization is an essential tool for isolation and purification of the compound in a robust and reproducible way. In addition, the crystallization conditions impact the crystal form or polymorph, particle habit, and its characteristics like stability and bio-availability. Optimized pharmaceutically-acceptable crystallization conditions are established by varying cooling profile and slurry conditions, by adding anti-solvent, or by applying seeding to obtain the preferred form, if needed.

Topics: Solid State API