Improving Stability of Vitamin B5 Through Double Salt Formation

Calcium pantothenate (CP) is a chemically unstable vitamin and sensitive to moisture, heat, acid, and alkali. The poor physicochemical properties have greatly limited its biological performance and applications. In this work, four new double salts of CP with pantoic acid calcium salt (PA), calcium isobutyrate (IBA), calcium β-hydroxy-β-methyl butyrate (HMB), and calcium lactate (LA) were synthesized aiming to reduce the moisture sensitivity and to enhance the stability. The three double salts (CP-PA, CP-IBA, CP-HMB) were fully characterized by single crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and dynamic vapor sorption. In addition, their hygroscopicity and chemical stability under different conditions were also studied. The results show that all four double salts present improved hygroscopicity, physical stability, and chemical stability. Notably, compared to CP pure forms, CP-PA and CP-LA present significantly lower moisture absorption and obviously improved stability. This work provides a new method to improve the hygroscopicity, physical stability, and chemical stability of organic salts.