What type of medication has a composition that includes undissolved particles?

A suspension is a type of medication in which undissolved particles are dispersed throughout a liquid medium. This characteristic means that the solid particles in a suspension do not dissolve but remain suspended, requiring the medication to be shaken before use to ensure an even distribution of the particles.

In contrast, a solution consists of a solute that is completely dissolved in a solvent, resulting in a homogenous mixture where the solute particles are not visible. Lotions are typically emulsions or suspensions that are designed for topical application, and they can contain various agents to help soothe or hydrate the skin but do not fundamentally fit the description of having undissolved particles in the same way as a suspension does. Capsules are solid dosage forms that contain medication in a gel or gelatin shell and do not involve the dispersion of undissolved particles in a liquid. These differences clarify why a suspension is accurately defined by its inclusion of undissolved particles.