This work reports the study of the racemic resolution of propranolol, an amino-alcohol with proven efficacy in the treatment of hypertension, ischemic heart disease and arrhythmia. Among all beta-blockers, propranolol was selected, as a case study, also due to its enantiomers diverse properties. The studies performed involve an enantio-selective extraction in a biphasic system, where propranolol first reacts with boric acid in aqueous media and then complexes with a chiral di-dodecyltartrate selector present in the organic phase. Factors affecting the extraction mechanism were analysed, namely the influence of the concentrations of the tartrate complexing agent and boric acid and the pH. A comprehensive mechanism of extraction is proposed. Due to its complexity the mathematical approach developed involves the use of a hybrid model, with a deterministic component, describing the material balance equations of the reactions involved, and a neural network, which allows accounting for the variable non-selective partition of propranolol. (c) 2006 Elsevier B.V. All rights reserved.