Sustained-release capsules are a type of medication designed to release their active ingredients slowly over time. This allows for a more consistent level of the drug in the bloodstream, reducing the need for frequent dosing. They are often used for medications that require a steady effect, such as pain relievers or antidepressants. These capsules are engineered with special coatings or formulations that control the rate of release. This technology helps improve patient compliance, as individuals can take their medication less often while still receiving the necessary therapeutic effects. Examples of sustained-release medications include morphine and metformin.