Intellectual property and chirality of drugs.

Chirality has emerged as a key issue in drug design, discovery and development. Chiral switches are drugs that are already approved and claimed as racemates but that have been redeveloped as single enantiomers. The legal state of the art of patentability of chiral switches, as derived from US and European precedents, is reviewed. The issues of intellectual property in the pending chiral switches of the blockbuster drugs ibuprofen, fluoxetine and omeprazole are analysed.