ABSTRACT
Pharmaceutical coatings serve a number of functions, probably the most important of which is to control the release of active pharmaceutical ingredient. Some coatings are employed to mask objectionable taste or to protect the ingredient inside from the environment, either air or water. Another function is to separate two physically or chemically incompatible ingredients packaged together in one tablet or capsule. Coatings are most commonly applied to tablets, the most common pharmaceutical dosage form now in use. Tablets are formed by compression of a powdered mixture of the active ingredients and binders and sometimes other excipients, the pharmaceutical term for any ingredient other than the active ingredient. Pharmaceutical coatings are often quite different from food coatings in composition, function, mathematical modeling, method of application, and technical sophistication (Table 12.1).
