How is a capsule characterized?

A capsule is characterized by its structure, which consists of medication enclosed within a hard or soft gelatin shell. This design allows for easy swallowing and helps to mask the taste of the medication. The gelatin shell can vary in composition, which may influence how quickly the contents are released in the digestive system.

In contrast, other forms of medication like tablets might be notched for splitting, but this does not define a capsule. Although certain capsules can be designed to dissolve upon contact with water, this is not a defining characteristic unique to capsules, as many forms of medication can dissolve in water. Additionally, while some capsules can be engineered for extended-release delivery, this is not a general trait of all capsules, as they can also be designed for immediate release. Therefore, the defining feature of a capsule is its specific composition of medication within a gelatinous shell.