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Updated: Jun 2, 2026

Coherent anti-Stokes Raman Scattering (CARS) Microscopy Visualizes Pharmaceutical Tablets During Dissolution
Published on: July 4, 2014
Unintended water mediated cocrystal formation in carbamazepine and aspirin tablets
Kapildev K Arora1, Nitin G Tayade, Raj Suryanarayanan
1Department of Pharmaceutics, University of Minnesota , Minneapolis, Minnesota 55455, USA.
Abstract:
The water of crystallization released during dehydration of dibasic calcium phosphate dihydrate (DCPD) mediated the cocrystal formation between carbamazepine (CBZ) and nicotinamide (NMA) in intact tablets. The dehydration of DCPD, the disappearance of the reactants (CBZ and NMA) and the appearance of the product (CBZ-NMA cocrystal) were simultaneously monitored by quantitative powder X-ray diffractometry. In a second model system, the water of crystallization released by the dehydration of DCPD caused the chemical decomposition of aspirin. Salicylic acid, one of the decomposition products, reacted with CBZ to form CBZ-salicylic acid cocrystal in tablets. This is the first report of cocrystal formation in intact tablets, demonstrating water mediated noncovalent synthesis in a multicomponent matrix. While the potential implications of such transformations, on both the mechanical and biopharmaceutical properties, can be profound, their characterization, using conventional solution based analytical techniques, can be challenging.
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