Spectrophotometric characterization of propanol-hydroxypropyl-β-cyclodextrin inclusion complex

Abstract

Cyclodextrins (CD) are a group of natural products formed during bacterial digestion of starch. These cyclic oligosaccharides consist of (a-1,4)-linked a-D-glucopyranose units and contain a hydrophobic central cavity and a hydrophilic outer surface. Cyclodextrins are well known for their ability to interact with poorly-water soluble compounds to form inclusion complexes thus increasing their apparent solubilities. For this reason, the most important application of CD in pharmaceutical industry is to enhance drug solubility in aqueous solutions. Propranolol is a very important ß-blocker drug, mainly used in the treatment of hypertension and cardiac arrhythmias. In this paper, a simple and rapid spectrophotometric method has been investigated for the study of inclusion complex of propranolol with hydroxypropyl-ß-cyclodextrin (HP???CD). The stoichiometry of propranolol- HP???CD complex has been determined by continuous variation (Job's plot) method and the overall association constant was determined by using Scott's method.