What type of medication allows for slow and continuous release over a predetermined period?

Extended-release medications are specifically formulated to dissolve and release their active ingredient slowly over a predetermined period of time, allowing for sustained therapeutic drug levels in the bloodstream. This formulation reduces the frequency of dosing, improves patient adherence, and minimizes peaks and troughs in plasma concentration that can cause adverse effects or loss of efficacy. Examples include extended-release formulations of metformin, metoprolol, and oxycodone. These preparations must never be crushed or chewed, because doing so destroys the release mechanism and delivers the entire dose at once, risking toxicity. A capsule is a dosage form in which the medication is enclosed in a gelatin shell; while some capsules can be extended-release, the term "capsule" alone does not describe the mechanism of slow continuous release. A lozenge is designed to dissolve slowly in the mouth for local or systemic effect via absorption through the buccal mucosa, but it is not a controlled-release systemic formulation. A suppository is administered rectally or vaginally and dissolves at body temperature for local or systemic absorption, but does not describe a time-controlled release mechanism. Understanding drug formulations is essential for safe administration and accurate client education.