ABSTRACT

INTRODUCTION The regulation of chiral drugs is, in principle, no different from the regulation of any other drug substance. Satisfactory standards of quality, safety, and efficacy need to be demonstrated for medicines containing chiral active ingredients before they can receive an authorization to place them on themarket. Of course, there are some special considerations or even challenges to take into account, particularly regarding the similar physicochemical properties of potential impurities in the traditional sense. Significant advances in synthetic, preparative, and analytical chemistry in the 1980s and 1990s allowed the development of synthetic, as opposed to the natural or semisynthetic, drug substances, which had dominated the area of stereochemically pure medicinal products up to then (e.g., Gal) (1). At the same time, there was increasing awareness of the different biological activities of stereoisomers and indeed the means to study these differences.