Ethical drug and Proprietary drug

Ethical drug noun - A drug that is available only with written instructions from a doctor or dentist to a pharmacist.

Proprietary drug and ethical drug are semantically related in proprietary medicine topic. In some cases you can use "Proprietary drug" instead a noun phrase "Ethical drug".

Proprietary drug noun - A drug that has a trade name and is protected by a patent (can be produced and sold only by the company holding the patent).

Ethical drug and proprietary drug are semantically related in proprietary medicine topic. You can use "Ethical drug" instead a noun phrase "Proprietary drug".