Substrate Considerations when Coating Solid Dosage Forms
The application of polymeric lms onto solid dosage forms (e.g., tablets, pellets, and capsules) is widely employed in the pharmaceutical eld for decorative, protective, and functional purposes [1-5]. Although dry coating has gained interest as a solvent-free technique [6-8], the majority of coatings are applied by a spray-atomization technique, with which polymers, either dissolved or dispersed in an aqueous or organic solvent, are sprayed onto substrates. Such coating processes are highly complex, involving coating formulation variables, processing variables, and substrate variables, all of which can impact the performance of the lm as shown in Figure 12.1. This chapter describes physical and chemical properties of solid substrates that can impact the coating process and ultimately inuence product performance.