Which term describes a liquid preparation in which solids are suspended in a suitable liquid medium?

• A. Powder for Injectable Suspension
• B. Injectable Suspension
• C. Injectable Emulsion
• D. Powder for Injection

Answer: (B)

The main idea is distinguishing a suspension from other dosage forms: a suspension is a liquid in which solid particles are dispersed, not dissolved. An injectable suspension specifically refers to a sterile liquid preparation in which finely divided drug solids are dispersed in a suitable medium so that, although they may settle over time, they can be re-dispersed with gentle shaking before administration. This is different from a solution (drug dissolved in liquid), an emulsion (two immiscible liquids with droplets of one dispersed in the other), or a dry powder that must be reconstituted before use. A powder for injectable suspension is a dry form that becomes a suspension only after reconstitution, so the term describes the starting material rather than the final liquid product. Therefore, the best term for a liquid preparation with solids suspended in a liquid medium is an injectable suspension.