proprietary drug vs brand-name drug

proprietary drug and brand-name drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
proprietary drug	Yes	No	No	No
brand-name drug	Yes	No	No	No

As nouns, proprietary drug and brand-name drug are synonyms defined as:

proprietary drug and brand-name drug: 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)

proprietary drug (noun)	brand-name 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)	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)