Synthesis of hydroxypropyl-β-cyclodextrin bonded silica-gel and its application to resolution

In order to set up a simple and effective method for resolution of optical isomers, hydroxypropyl-p-cyclodextrin was bonded to silica-gel, which can be used for preparation of thin-layer chromatography plates. Resolution of clenbuterol and propranolol were investigated on these thin-layer chromatography plates using different combinations of solvent systems at ambient temperature. The best simultaneous resolution was achieved in solvent system of acetonitrilen-butanol (50:50, v/v). R-st values of resolution of clenbuterol hydrochloride and propranolol hydrochloride are 3.6 and 4.3, respectively. The spots of different enantiomers are separated clearly. The results showed that hydroxypropyl-beta-cyclodextrin bonded silica-gel could be successful in resolution of chiral adrenergic drugs. The study offers a direct, rapid and reliable method for separation of this kind of optically active compounds.