The proposed work is directed toward the investigation of a new membrane- based process for separation of enantiomers in a racemic mixture. Many biologically active substances are chiral, and in general only one of the enantiomers in the racemic mixture produces the desired biological activity. Frequently the unwanted enantiomer inhibits the desired biological activity of the active enantiomer and/or exhibits undesirable side effects. The best currently available enantiomer resolution schemes (e.g., fractional crystallization and chiral chromatography) have a number of drawbacks, including the following: 1) they have low resolution, particularly when scaled up to a practical size; 2) they are labor- intensive; and 3) they are difficult to operate continuously. This proposal describes a new membrane-based process for enantiomer resolution. This process employs cyclodextrin (a macrocyclic oligosaccharide) as a mobile carrier in a liquid-membrane operation. During Phase I we will demonstrate the feasibility of the process for the isolation of D-propranolol, an important beta-blocker drug, from a racemic mixture of D, L-propranolol.