The cracking of film coatings on film-coated tablets—a theoretical approach with practical implications
Author:
- 1 September 1981
- journal article
- Published by Oxford University Press (OUP) in Journal of Pharmacy and Pharmacology
- Vol. 33 (1) , 423-426
Abstract
A theoretical approach of film cracking is presented using equations which allow for the calculation of both the internal stress in a film coating due to shrinkage of the film on evaporation of the solvent and the thermal stress due to differences in the thermal expansion of the film coating and tablet substrate during changes in temperature arising out of the coating processes. The practical implications of this approach in film formulation are discussed with particular reference to the choice of tablet core formulation, the grade of polymer used, the type and concentration of both plasticizers and pigments and the solvent system used in the coating process.Keywords
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