Potentiometric Study of Carbisocaine Micellization and Inclusion Complexation with α-Cyclodextrin, β-Cyclodextrin, Methyl-β-cyclodextrin, and (Hydroxypropyl)-β-cyclodextrin
| Autor: | Mária Vojteková, Miloš Vrana, František Kopecký, Katarína Čížová |
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| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | Collection of Czechoslovak Chemical Communications. 67:245-256 |
| ISSN: | 1212-6950 0010-0765 |
| DOI: | 10.1135/cccc20020245 |
| Popis: | Micellization of the local anesthetic drug carbisocaine hydrochloride (BHCl) was studied by potentiometry with both cation- and anion-selective membrane electrodes in aqueous solution at 25 °C. The found critical micelle concentration 0.022 mol dm-3 and the concentration course of the free carbisocaine cation and chloride counterion in the micellar solution corresponded to the characteristic of cationic surfactants. In a more dilute aqueous solution, below critical micelle concentration, the complexation of carbisocaine cation BH+ with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD) and its random substituted methyl (M-β-CD) and hydroxypropyl (HP-β-CD) derivatives was followed using the prepared cation-selective electrodes. The potentiometric data corroborated formation of the carbisocaine-cyclodextrin complexes (BH+)CD (1 : 1) with all the cyclodextrins and the respective complexation constants K11 were estimated using a modified Scatchard method. Slight deviations from 1 : 1 plots were marginally observed with α-CD and HP-β-CD. Bigger K11 value of the complexation with α-CD in comparison with β-CD indicated inclusion of the carbisocaine C7 alkyl chain into the cyclodextrin cavity and the role of the hydrophobic interaction in complexation with β-CDs was emphasized by the increasing magnitude of K11 in the order of HP-β-CD < β-CD < M-β-CD. |
| Databáze: | OpenAIRE |
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