Related Experiment Video
Updated: Jun 23, 2026

Electrophysiological Methods to Assess Peripheral Pain Block in an Anesthetized Rat
Published on: November 21, 2025
Complex of branched cyclodextrin and lidocaine prolonged the duration of peripheral nerve block
Ryoko Suzuki1, Young-Chang P Arai, Kenichi Hamayasu
1Department of Thoracic & Cardiovascular Surgery and Regeneration Technology, Kochi Medical School, Kochi, Japan.
Abstract:
Although laboratories have tried to synthesize new local anesthetics, currently available local anesthetics rarely provide prolonged regional blockade. New models of sustained-release preparations of local anesthetics with liposomes and microspheres have been studied to prolong the duration of the effects of the local anesthetics. In the present study, we examined whether a complex of a branched cyclodextrin (CD), 6-O-alpha-D-maltosyl-beta-cyclodextrin (G2-beta-CD) and lidocaine could prolong local nerve block when compared with plain lidocaine. The sciatic nerve in male Sprague-Dawley rats was blocked with plain lidocaine (n = 10), the complex of G2-beta-CD + lidocaine (n = 10), or plain G2-beta-CD (n = 4). Sensory block was assessed with a hotplate set at 56 degrees C. The median duration of the block was longer in the complex group than in the plain lidocaine group (110 min; range, 70-150 min vs 55 min; range, 40-80 min; P < 0.05), thus demonstrating that the complex with CyD significantly prolonged the nerve block effect of lidocaine. In conclusion, the present study showed that this encapsulating technique with CyD is useful to expand local anesthetic effect in peripheral nerve blockade.
Related Concept Videos
Depolarizing Blockers: Pharmocokinetics
Local Anesthetics: Mechanism of Action
Local anesthetics are amphiphilic molecules consisting of a hydrophobic aromatic part linked to a hydrophilic group by an ester or amide linkage. They are weak bases and are usually available as salts, which increases their solubility and stability. Once administered, LAs exist in the body either...
Local Anesthetics: Pharmacokinetics
Depolarizing Blockers: Mechanism of Action
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
Local Anesthetics: Clinical Application as Surface, Infiltration, and Conduction Block Anesthesia
Local Anesthetics: Differential Sensitivity of Nerve Fibers
