Study about Encapsulation of Vitamin C into \(\beta\)-Cyclodextrin: An Approach towards Advancement and Regulatory Release

Abstract

Host–guest inclusion complexes of \(\beta\)-cyclodextrin with two vitamins namely, nicotinic acid and ascorbic acid in aqueous medium have been explored by reliable spectroscopic, physicochemical and calorimetric methods as stabilizer, carrier and regulatory releaser of the guest molecules. Job plots have been drawn by UV-visible spectroscopy to confirm the 1:1 stoichiometry of the host-guest assembly. 2D NMR spectroscopy has been used to elucidate the inclusion complexes' stereo-chemical composition. Studies on conductivity and surface tension bolster the inclusion process even more. With the use of the van't Hoff equation and UV-visible spectroscopy, association constants for the vitamin-\(\beta\)-CD inclusion complexes have been obtained, and thermodynamic parameters have been calculated using the Benesi-Hildebrand technique and non-linear programme. To accurately measure the stoichiometry, association constant, and thermodynamic characteristics, isothermal titration calorimetric investigations have been carried out. The outcomes reveal that there is a drop in \(\Delta S\)0, which is overcome by higher negative value of \(\Delta H\)0, making the overall inclusion process thermodynamically favorable. The association constant is found to be higher for ascorbic acid than that for nicotinic acid, which has been explained on the basis of their molecular structures.