Objective: To determine the optimal additive form of volatile oil in Zhitong cataplasms by comparing the effect of additive forms of volatile oil on this preparation

such as direct addition method

β-cyclodextrin inclusion method and microemulsion method. Method: The physical properties of the matrix were compared

such as the initial adhesive force

the sticking force

the peel strength and formability.Effect of three different ways of adding volatile oil on the in vitro release were compared by taking ferulic acid and ligustilide as indexes.The volatile oil content was taken as the index

and its stability was compared. Result: The addition of volatile oil affected the physical properties of the matrix

but Zhitong cataplasms prepared in the form of microemulsion had little effect.In 24 hours

the cumulative releases of ferulic acid in Zhitong cataplasms prepared by direct adding method

β-cyclodextrin inclusion method and microemulsion method were 563.45

454.4

419.5 μg·cm-2

and the cumulative releases of ligustilide were 871.40

792.60

550.07 μg·cm-2

respectively.Compared with direct addition method and β-cyclodextrin inclusion method

the stability of Zhitong cataplasms prepared by microemulsion method was the best. Conclusion: The addition of essential oil affects the physical properties

in vitro release and stability of the matrix in Zhitong cataplasms

the microemulsion method has little effect on the adhesion of the matrix and stability of Zhitong cataplasms

but the cumulative releases of active ingredients are less than direct adding method and β-cyclodextrin inclusion method.