Objective: To optimize formulation of thermo-sensitive in situ nasal gel of α-asarone nanoparticles and investigate its in vitro release behavior. Method: With amounts of poloxamer 407 and poloxamer 188 as independent variables

gelation temperature as an dependent variable

multilinear and quadratic models were used to estimate the relationship between dependent variable and independent variables and to select the formulation by central composite design-response surface methodology.Artificial simulated nasal fluid was applied as release medium to study in vitro release characteristics of α-asarone nanoparticles in situ gel. Result: Optimal formulation was as follows:poloxamer 407 of 21.85% and poloxamer 188 of 3.8%

gelation temperature was (33.7±0.1)℃.Within 72 hours

accumulative release of α-asarone was 70.42%. Conclusion: α-asarone nanoparticles in situ gel possesses a superior sustained-release effect

the optimum formulation provides a basis for development of new administration routes and dosage forms of α-asarone.