Drug delivery capsule. Coloured scanning electron micrograph (SEM) of a burst drug delivery capsule revealing smaller capsules (blue) inside it. Some drugs work best when delivered to a specific site in the body. They can be encased in a capsule that is designed to burst only at that point, in response to its environment. This capsule can contain not just the drug but also other capsules containing other drugs, which can be targeted at other parts of the body.