Recent advances, challenges and perspectives in enantioselective release.

Development of chiral drugs has become one of the most important subjects for academic research and pharmaceutical industry. Even though it has been well known that a pair of enantiomers of a chiral drug frequently have different biological and physiological effects, a certain number of chiral drugs are currently still commercialized and used in the form of racemate. In the above context, investigation of enantio-differentiating release and enantioselective effects may lead to alternative use approaches for chiral drugs. In spite of the noticeable advancements, there has been no review paper yet focused on enantioselective release, except the earlier one published by us (Ind. Eng. Chem. Res. 2016, 55, 6037). The present paper reviews the latest advancements made in enantioselective release, with emphasis on the construction of chiral releasing materials. The currently existing difficulty in performing enantioselective release and the emerging issues associated with chiral drugs (and chiral agrochemicals, etc.) are summarized. The issues include: enantioselective effects in chiral carrier-chiral guest compound and chiral carrier-achiral guest compound releasing systems; chiral inversion in release process; chiral pollutants in environment, etc. The review paper might provide new insights into the development and use of chiral drugs.