What is the most commonly used coating method for tablets?

The most commonly used coating method for tablets is polymer film coating. This technique involves applying a thin layer of polymer-based coating to the tablet, which serves multiple purposes. Polymer film coatings are advantageous because they provide a smooth finish, enhance the appearance of the tablets, and protect them from environmental factors such as moisture and light. Additionally, the coating can help mask unpleasant tastes or odors found in some active pharmaceutical ingredients.

Film coatings are typically thinner than sugar coatings, which makes them less bulky and more efficient in terms of production. They also allow for versatility in tailoring drug release characteristics, such as delaying or controlling the release of the active ingredient. This flexibility, along with the efficiency of application in a commercial setting, makes polymer film coating the preferred method for many tablet formulations.

Other coating methods, while still used, generally have more specific applications or limitations. Sugar coating, although historically significant, is less common due to the labor-intensive nature of the process and the larger surface area requirements. Enteric coating is primarily aimed at protecting the drug from stomach acid and ensuring release in the intestines, making it specific to particular formulations where such release characteristics are required. Early coating is not a widely recognized method in the context of tablet coating formations.