(252b) Overview of Film-Coating Technologies in the Pharmaceutical & Nutritional Industries

Film coating is a complex unit operation that has been utilized for the application of surface coatings to pharmaceutical and nutritional products for half a century.

During that time frame, what appear to be significant advances in coating materials and processing technologies have been made. However, such advances have come as the result of a series of iterative steps rather than as a result of a major paradigm shift.

In spite of the successful implementation and global acceptance of film coating processes, surprisingly, much still has to be understood about the underpinning concepts that impact finished product quality (in its broadest sense). In general terms, as long as finished product meets required specifications, little concern is shown for how such objectives are achieved. Implementation of PAT initiatives will potentially provide the driving force for change in this regard.

While pharmaceutical and nutritional products are aimed at different markets, and thus often have to comply with a different set of regulations, the challenges with respect to applying film coatings to products in each of these industries remain remarkedly similar.

Film coating is fundamentally a process involving the application of liquid coating systems to the surface of suitable cores in such a manner that the rate at which the coating material is applied, and the manner in which the solvents from that coating system are effectively removed, are carefully balanced. In addition, the means by which that coating material is unformly distributed across the surfaces of the core material is a critical factor in achieving the required quality and technical attributes of the final product.

This presentation will provide an overview of current film-coating practices used in the pharmaceutical and nutritional industries, outlining the challenges that have to be faced, and reviewing some important tools that may be used in meeting these challenges. In particular, process thermodynamics, and factors critical to an understanding of how coatings are distributed across the surface of the core material being coated, will be discussed. The consequences of failing to gain a good understanding of these issues will be discussed in terms of impact on product quality, functionality, stability, and process economics.