Studies of lidocaine-lecithin microemulsion

Key words: 
• Microemulsion /
• lidocaine /
• lecithin /
• transdermal absorption

Abstract: Objective To study the formation of transdermal delivery system of lidocaine with lecithin microemulsions as delivery system.Methods Area of water in oil microemulsions was investigated through pseudo ternary phase diagrams. Viscosity of microemulsions were measured to select the the right formulation using orthogonal test method. The content of hydrochloride lidocaine in microemulsions was measured by spectrophotometric. Results Nature of cosurfactant and K m showed predominant influence on the area of microemulsions, area of microemulsions in propanol and iso propanol system were larger. The area of microemulsions was larger in low purity lecithin system. Cosurfactant showed predominant influence on the viscosity of the microemulsion. Content of lidocaine was measured at 262nm, the standard curve was linear in the range of 0.02～0.5mg/mL, the average recovery was (100.17±0.16)%, the within day and between day precision of determination of lidocaine was 0.0137±0.0121, 0.0119±0.0115. Conclusion Choosing mixed surfactant will help the formation of microemulsion. Nature and potent of alcohol have very important effect on selection of the formulation of lidocaine transdermal microemulsions.