Cyclodextrin effects on physical–chemical properties of novocaine |
| |
Authors: | Emilia Iglesias-Martínez Isabel Brandariz Francisco Penedo |
| |
Institution: | 1. Departamento de Química Física e Enxenería Química I, Facultad de Ciencias, Universidad de La Coru?a, 15071, Coru?a, Spain
|
| |
Abstract: | The UV-vis absorption and the fluorescence emission spectra of novocaine were analysed in aqueous cyclodextrin (CD) solutions.
Either the absorbance read at λmax 290 nm or the fluorescence emission intensity at λems 346 nm increase in the presence of both α- and β-CD due to the formation of 1:1 inclusion complexes. The lower polarity of
the CD-cavity sensed by the included drug enhances the emitted fluorescence; in fact, the same effect was observed in aqueous
mixtures of acetonitrile, dioxane, or dimethylsulfoxide. The inclusion complex formation between the monocation of novocaine
and CDs diminishes the electrical conductance of aqueous solutions of novocaine hydrochloride (NoHCl). Both the nitrosation
reaction in aqueous acid medium and the ester hydrolysis in alkaline medium are retarded in the presence of CDs. The strongest
effect was observed with β-CD as a consequence of the higher stability inclusion complex. |
| |
Keywords: | Cyclodextrins Electrical conductance Ester hydrolysis Fluorescence emission Inclusion complexes Nitrosation Novocaine |
本文献已被 SpringerLink 等数据库收录! |