Enteric gelatin hollow capsules
are a type of capsule which has a special coating. This coating prevents the drugs from affecting the digestive system in the acidic environment of the stomach. The coating is mainly made from anti-adhesion agents, plasticizers, colorants, and film forming polymers.
Enteric coated capsules are perfect for medications with fast or time-sensitive release. They also provide excellent bioavailability.
The enteric coating process starts with the application of a thin layer of gelatin. It is followed by cutting, nesting, and inspection.
After that, a coating material of 6-10% is added. Auxiliary agents account for 0.2-5%. Another ingredient, pharmagel, accounts for the remaining 80-95%.
These capsules have a low moisture content and toughness. Therefore, the capsule is not likely to rupture even if the hygroscopicity is high.
During production, a number of tannin extracts are needed. This allows for a variety of different coating methods. Some of these include hot melt coating, electrostatic coating, and pan coating.
In addition, the capsule has an auxiliary agent to help protect the drug from the acidic environment of the stomach. However, this is only part of the process.
As a result, some of these capsules may have a glossy appearance. But, if the coating is too thin, it may break during the manufacture of the product.
An enteric coating can be applied using aqueous polymer dispersions. To build flexibility, a plasticizer must be added.
In order to achieve maximum efficiency, it is important to optimize the process variables. For example, if the moisture content of the capsule is too low, the capsule may be too soft. And if the pH is too acidic, the coating will dissolve too quickly.