A consideration of the patentability of enantiomers in the pharmaceutical industry in the United States.

During the last thirty years, concern over stereoselectivity of drug action has drawn a great deal of interest within the pharmaceutical field due to an improved understanding of the pharmacology and pharmacokinetics of enantiomers. Developing single enantiomers versus racemates or introducing a single enantiomer following the development of the racemic mixture appears to be the new trend. The intellectual property status of single enantiomers from racemates may be unclear. Drug discoverers and patent attorneys must examine the examples of the past to establish an appropriate pathway towards the development and intellectual property protection of chiral drugs. The review will focus on the patenting of an enantiomer in view of the prior art disclosure for the racemic mixture.