Which of the following is an example of a medication that is neither solid nor liquid?

A gel is considered a form of medication that is neither solid nor liquid; rather, it is a semi-solid substance. Gels contain a mixture of a gelling agent and a liquid, which gives them their unique texture. They can maintain their shape while still being somewhat fluid in nature, allowing them to be easily spread or applied to the skin or mucous membranes. This property makes them useful in various medical and pharmaceutical applications, as they can encapsulate active ingredients while providing a suitable medium for administration.

In contrast, tablets, capsules, and troches are all classified as solid forms of medication. Tablets are compressed powders that dissolve in the body, capsules are usually made of gelatin and contain powder or liquid medication inside, and troches are solid medicated lozenges designed to dissolve in the mouth. Each of these forms has specific characteristics that differentiate them from gels and define them within the solid medication category.