Use of ion-exchange membranes to measure transfer free energies of charged local anesthetics: Correlation to anesthetic potency
✍ Scribed by Norihito Kitagawa; Yoshiroh Kaminoh; Mitsuhiro Takasaki; Issaku Ueda
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 476 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
Ion-selective electrodes, sensitive to local anesthetic cations, were prepared with carboxylated poly(viny1 chloride) (PVC) membranes. Three plasticizers with varying degrees of polarity were used to adjust the hydrophobicity of the membrane. The affinity of the drug to the ion-exchange membrane was measured by the electromotive force of the cation-selective electrodes. The difference in the transfer free energies of the anesthetics for the membrane was estimated in reference to dibucaine. The values correlated to their clinical potencies. By comparing drugs with similar structures, the transfer free energy per methylene moiety linked to the hydrophilic domain was found to be -1.7 kJmot-', and that of CI linked to the hydrophobic domain was -3.1 kJmol-'.