What characterizes a nonproprietary drug?

A nonproprietary drug, also known as a generic drug, is characterized by being a drug that does not have a brand name and is typically recognized by its chemical name. The term "nonproprietary" indicates that the drug is not owned by a specific company and is available for production by multiple manufacturers once the original patent has expired.

Choosing options that focus on specific characteristics, such as containing controlled substances or being restricted to oral administration, does not define a nonproprietary drug. Similarly, while many nonproprietary drugs may require a prescription, not all do, as some may be available over-the-counter. Therefore, these criteria do not aptly identify nonproprietary drugs.

The option regarding biologicals or substances from glandular origin is a more nuanced descriptor. Nonproprietary drugs can indeed encompass biological products or substances derived from biological sources, provided that they are recognized as generic equivalents. This aligns more closely with a broad understanding of the classification and characteristics of nonproprietary drugs, making it the most relevant choice among the given options.