Purpose: For the topical anesthetic, transcriptional transactivator peptide (TAT) modified lidocaine (LID) loaded nanostructured lipid carriers (TAT-NLCs-LID) were prepared and then used for improving transdermal delivery of local anesthetic drug. Methods: In this study, TAT was conjugated with Distearoyl phosphatidylethanolamine-(polyethylene glycol)2000-maleimide (DSPE-PEG2000-Mal) to obtain TAT-PEG2000-DSPE. TAT-NLCs-LID were successfully prepared and characterized by determination of their particle size, morphology, drug encapsulation efficiency andin vitrodrug release behavior. The skin permeation of LID-LNPs was examined using a Franz diffusion cell mounted with depilated mouse skinin vitroandin vivoanesthesia effect was evaluated on mice. Results: The results showed that TAT-NLCs-LID have substantially small mean diameter (157.9 nm) and high encapsulation efficiency (81.8%). From thein vitroskin permeation results, transdermal flux of TAT-NLCs-LID was about several times higher than that of LID solution and NLCs-LID.In vivoanesthesia effect evaluation illustrated that TAT-NLCs-LID can enhance the transdermal delivery of LID by reducing the pain threshold in mice. Conclusion: These results indicate that the novel TAT containing drug delivery system is very useful for overcoming the barrier function of the skin and could deliver anesthetic through the skin. TAT-NLCs-LID could function as promising topical anesthetic system. [ABSTRACT FROM AUTHOR]