Related Experiment Video
Updated: Mar 4, 2026

Subcutaneous Trigeminal Nerve Field Stimulation for Refractory Facial Pain
Published on: May 10, 2017
Extended local anesthesia enabled by flavonoid permeation enhancers
Yiyuan Han1, Matthew Torre2, Xiaojing Ma1
1Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115.
Abstract:
Site 1 sodium channel blockers (S1SCBs), such as tetrodotoxin (TTX) and neosaxitoxin, are ultrapotent local anesthetics with low tissue toxicity. Their duration of action is relatively brief, but increasing the dose can lead to systemic toxicity. Here, we report that selected flavonoids-puerarin (PUE), naringenin, and kaempferol-prolong nerve block from S1SCBs 4- to 25-fold. Using both tympanic membrane (TM) permeation and sciatic nerve fluorescence distribution models, we demonstrate the flavonoids increase drug penetration across biological barriers (the TM and the barriers in and around nerve), suggesting that they act as chemical permeation enhancers (CPEs). Importantly, flavonoids exhibited minimal tissue toxicity compared to conventional CPEs. Coencapsulation of TTX and PUE into a liposomal delivery system further prolonged local anesthesia to over 25 d from a single injection. These findings establish flavonoid compounds as a safe class of CPEs and provide a platform of long-acting, nonopioid pain therapies. Flavonoids may be attractive alternatives to conventional CPEs in biomedical applications.
More Related Videos
08:05Occlusion of the Great and Small Saphenous Vein Using Copolymeric Glue Based on N-Butyl Cyanoacrylate and Methacryloxy Sulfolane
Published on: December 9, 2022
05:43Topical Airway Anesthesia for Awake-endoscopic Intubation Using the Spray-as-you-go Technique with High Oxygen Flow
Published on: January 13, 2017
Related Concept Videos
Local Anesthetics: Common Agents and Their Applications
Cocaine is an ester of benzoic acid and methylecgogine. It is used to anesthetize and vasoconstrict locally. Currently, it is used primarily for topical applications. It is beneficial for surgeries on the upper respiratory tract, providing anesthesia and shrinking the mucosa. Cocaine in the form of cocaine hydrochloride is...
Local Anesthetics: Pharmacokinetics
Local Anesthetics: Chemistry and Structure-Activity Relationship
Local Anesthetics: Clinical Application as Surface, Infiltration, and Conduction Block Anesthesia
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: Clinical Application as Intravenous Regional Anesthesia
One of the advantages of...