Proprietary medicines are substances which some one has an exclusive right to make or sell for medicinal purposes. The exclusive right may depend on secret methods of manufacture, or on a patent on the method of preparation, as in Germany, or on process and substance both, as in America, or on a copyright on the substance. A patent on the name, or a copyright, is one of the most effective methods of acquiring and maintaining exclusive rights in the case of medicines whose virtues are fictitious, though secrecy is in some cases equally effective, for a time.
Proprietary medicines are not either good or bad by reason of their origin. In the language of the day, none are "ethical" or "unethical" per se. The possibility of greatest danger occurs among secret preparations and depends partly on the fact that secrecy regarding a remedy may have more serious consequences than secrecy
DOCK G. PROPRIETARY MEDICINES AND THEIR ABUSES.. JAMA. 1906;XLVII(13):978-982. doi:10.1001/jama.1906.25210130002001a