What is the role of a plasticizer in tablet coating?

A plasticizer is an essential component in tablet coating processes, particularly regarding the properties of the polymer film that forms the coating. Its primary role is to add flexibility to the polymer film, which is crucial for several reasons.

When tablets are coated, the polymer film needs to be pliable enough to accommodate mechanical stress that occurs during handling, packaging, and administration. Without sufficient flexibility, the coating may crack, peel, or otherwise fail to protect the tablet effectively. Plasticizers lower the glass transition temperature of the polymer, making it more flexible and less brittle, which is essential for maintaining the integrity of the coating under various conditions.

Furthermore, the addition of a plasticizer can improve the adhesion of the coating to the tablet core, ensuring a more uniform and effective coating that provides better protection against environmental factors and enhances the overall performance of the tablet.

This flexibility contributed by the plasticizer is particularly beneficial in formulations where the coated tablets require a degree of deformation without compromising the barrier properties of the film.