Optimizing the morphology of calcium d-pantothenate by controlling phase transformation processes

Abstract

Calcium D-pantothenate, also known as VB5, is one of the most important feed additives. It typically assumes a needle-like morphology that easily agglomerates, resulting in poor flowability and low bulk density. Here, we develop a route to prepare calcium D-pantothenate in a block-like morphology with good flowability and high bulk density. Also, the solvent-mediated phase transformation of calcium D-pantothenate methanol solvate (D-PC·MeOH) into D-pantothenate tetramethanol monohydrate (D-PC·4MeOH·H₂O) was investigated by in situ ATR-FTIR spectrometry and Raman spectrometry, and the data was subsequently correlated by the Johnson–Mehl–Avrami model. Results demonstrate that the rate-controlling step was the nucleation and growth of D-PC·4MeOH·H₂O. Careful control over the thermal transformation process of D-PC·4MeOH·H₂O enabled the formation of solvent-free calcium D-pantothenate in a block-like morphology. Molecular dynamics simulations enabled a deeper understanding of the effects of temperature on the phase transformation process. This work provides a framework to scale the production of calcium D-pantothenate to industrial levels.