Prolonged Regional Anesthesia with Lidocaine Microspheres by Using a Biodegradable Polymer.
10.4097/kjae.1999.36.2.305
- Author:
Jeong Ok LIM
1
;
Sung Sik PARK
;
Woon Yi BAEK
Author Information
1. Department of Anesthesiology, School of Medicine, Kyungpook National University, Taegu, Korea.
- Publication Type:In Vitro ; Original Article
- Keywords:
Anesthesia, duration;
Anesthetics, local, lidocaine;
Microspheres, polymer
- MeSH:
Anesthesia, Conduction*;
Anesthetics, Local;
Animals;
Chromatography, Liquid;
Dexamethasone;
Lidocaine*;
Microspheres*;
Peripheral Nerves;
Polymers*;
Rats;
Sciatic Nerve;
Suspensions
- From:Korean Journal of Anesthesiology
1999;36(2):305-310
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Biodegradable microspheres are a useful method of drug delivery because they are both injectable and biodegradable. Previous work in our group has characterized implantable preparations of local anesthetics in pellets for prolonged regional anesthesia. In this paper we evaluated injectable suspensions of lidocaine-polymer microspheres for extended period of percutaneous sciatic nerve blockade in rats. METHODS: Microspheres were prepared using poly (lactide-co-glycolide) loaded with 50 wt% lidocaine by a solvent evaporation method. In vitro release rate of lidocaine from microspheres was determined by high performance liquid chromatography (HPLC). Percutaneous blockade of the rat sciatic nerve was performed, and sensory blockade of the nerve was assessed using an analgesiometer. RESULTS: Lidocaine was released in a controlled manner in vitro. In general 60% of the drug released in the first day, 80% in two days. Sciatic nerve blockade duration ranged from 8 to 12 hours. Incorporation of dexamethasone 0.05 wt% into the microspheres resulted in significant prolongation of block. CONCLUSION: Prolonged percutaneous blockade of peripheral nerve is achieved using biodegradable polymeric lidocaine microspheres.
