Chiral recognition and quantification of propranolol enantiomers by surface enhanced Raman scattering through supramolecular interaction with β-cyclodextrin.

A simple, fast and accurate method of chiral recognition and quantification of propranolol enantiomers by surface enhanced Raman scattering (SERS) and multivariate regression analysis through supramolecular interaction with β-cyclodextrin is reported. Computational chemistry served as a tool of elucidating the underlying mechanism of molecular interactions responsible for chiral discrimination. The influence of several factors (nature and concentration of chiral auxiliary, selector-selectand ratio, pH, interaction time, etc.) over the obtained SERS spectra was assessed, followed by the construction of the chemometric model with the optimized operational conditions. The performance of the obtained semi-empirical model was established using a validation set of pure enantiomers and its intended use was demonstrated by the assessment of the enantiomeric excess of propranolol in pharmaceutical formulations (tablets) without the need of tedious and expensive chiral separation. The obtained results were also confirmed by chiral high-performance liquid chromatography.