The Evaluation of Topical Anesthetic Effects of a Liposome Encapsulated Mixture of Local Anesthetics (Lipo-MLA).
10.4097/kjae.2001.40.3.420
- Author:
Sung Sik PARK
1
;
Kyu Seok HAN
;
Woon Yi BAEK
Author Information
1. Department of Medicine, Graduate School, Kyungpook National University, Daegu, Korea.
- Publication Type:Original Article
- Keywords:
Anesthetics, local: lidocaine;
liposome;
tetracaine
- MeSH:
Adult;
Anesthetics*;
Anesthetics, Local*;
Bandages;
Cholesterol;
Egg Yolk;
Forearm;
Humans;
Lidocaine;
Liposomes*;
Occlusive Dressings;
Phosphatidylcholines;
Tetracaine;
Volunteers
- From:Korean Journal of Anesthesiology
2001;40(3):420-426
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: This study investigated the effect of topical analgesic effects of a liposome encapsulated mixture of local anesthetics (lipo-MLA) compared with EMLA. METHODS: 3% lipo-MLA (0.5% tetracaine base, 2.5% lidocaine base) and 5% lipo-MLA (1% tetracaine base, 4% lidocaine base) were encapsulated into liposomal vesicles made with egg yolk phosphatidylcholine, cholesterol and phosphatidyldioleoyl. 3% lipo-MLA and EMLA were applied to volunteers' forearms bilaterally with and without an occlusive dressing. The topical anesthetic effects of the lipo-MLA and EMLA as a control were evaluated by the pinprick test in 28 adult volunteers after 60 minutes of application. The analgesic influence of the concentration of local anesthetics was also compared with 3% and 5% lipo-MLA under a non-occlusive dressing. RESULTS: Analgesic effects of the 3% lipo-MLA were similar with EMLA under an occlusive dressing for 60 minutes. In addition, analgesic effects of the 3% lipo-MLA under a non-occlusive dressing were more potent than EMLA. Lipo-MLA under a non-occlusive dressing showed more potent analgesic effect than lipo-MLA under an occlusive dressing. 5% lipo-MLA was more potent than 3% lipo-MLA under a non-occlusive dressing. CONCLUSIONS: Lipo-MLA has more potent analgesic effects than EMLA without an occlusive dressing and 5% lipo-MLA is more potent than 3% lipo-MLA. Therefore, lipo-MLA appeared to be an improved topical analgesic formulation which provides a more potent and convenient topical application.
