On Apr. 22. 1988, the Prescription Drug Marketing Act of 1987 (PDMA) was signed into law by the President on April 22, 1988. The Act banned the diversion of prescription drugs from legitimate commercial channels.

The U.S. Congress found that the resale of such drugs leads to the distribution of mislabeled, adulterated, subpotent, and counterfeit drugs to the public. The new law required drug wholesalers to be licensed by the states; restricts reimportation from other countries; and banned sale, trade or purchase of drug samples, and traffic or counterfeiting of redeemable drug coupons.