Film coating of solid oral dosage forms is a well established process in the pharmaceutical industry. Although, the process itself is based on the laws of thermodynamics, the result is strongly dependant on the rheological characteristics of the film coating dispersion applied. Issues such as logo bridging, orange peel and spray drying are rooted in the viscous and elastic properties of the coating formulation. Determining and appraising the rheological characteristics is therefore of huge importance in order to prevent problems during the film coating process.
Moreover, in the field of instant release film coating, the process time and, as a result, the manufacturing costs are directly linked to the solid matter content of the dispersion. As viscosity is a specific characteristic of the film forming polymer, rheological investigation is very useful and important in order to select the most economical formulation.
A copy of this application package note is available by quoting reference no: V234