Psilocybin: Characterization of the Metastable Zone Width (MSZW), Control of Anhydrous Polymorphs, and Particle Size Distribution (PSD)
ACS Omega February 7, 2022 Robert B. Kargbo, Alexander M. Sherwood, Poncho Meisenheimer et al. 5 citations
A thermodynamically controlled crystallization process for psilocybin, a serotonergic agonist granted breakthrough therapy status for depression, produces crystals with stronger interactions, a controlled particle size distribution, and an improved impurity profile compared to a faster, kinetically controlled process that yields smaller particles. Real-time monitoring with high-resolution inline microscopy measured particle size and metastable zone width and nucleation induction. Water recrystallization forms polymorph B (trihydrate) independently of the method, while polymorph A (anhydrate) and polymorph H (anhydrate) depend on drying: room-temperature vacuum drying yields mainly polymorph A, and heating even at low temperatures produces a mixture of polymorphs A and H.