Abstract:

BACKGROUND: In vivo half-life period of local anesthetic drugs used in clinic is short, and a high dose in local tissue can easily lead to central nervous system and cardiovascular toxicity. Therefore, scholars have begun to study sustained-release local anesthetic delivery system.
OBJECTIVE: To conclude the progress in preparation and analgesic effect of sustained-release local anesthetic drugs.
METHODS: A computer-based search of VIP databases was performed for articles published from January 1998 to October 2009, addressing the preparation and analgesic effect of sustained-release local anesthetic drugs, by using “local anesthetic drugs, microsphere, lactic acid glycolic acid, in vitro drug release, analgesic”. Totally 33 articles were selected.
RESULTS AND CONCLUSION: The microspheres, which were prepared by using W1/O/W2 double emulsion-solvent evaporation method, emulsion-solvent evaporation method, emulsion-crosslinking method, and high voltage electric field method. The microspheres were spherical shape with good mobility, and 80% of them are 50-100 μm in diameter, which can increase the drug loading and encapsulation efficiency. It was observed that the in vitro release time was prolonged, and a relatively stable plasma concentration was obtained. A better sustained action and safety was found.