Objective:To establish a new method

internal homogenate method

for cyclodextrin inclusion of volatile oil in Menthae Haplocalycis Herba

and provide a new reference for the selection of inclusion method. Method:In this paper

volatile oil in Menthae Haplocalycis Herba was selected as the model drug.The advantages and disadvantages of saturated aqueous solution method

ball milling method

colloid milling method and internal homogenate method were compared

taking inclusion rate of volatile oil as index

orthogonal design was used to optimize the inclusion process.Thin layer chromatography(TLC)

microscopic imaging analysis and Fourier transform infrared spectroscopy(FT-IR) were employed to characterize the inclusion complex

and GC-MS was used to analyze the components of volatile oil in Menthae Haplocalycis Herba before and after inclusion. Result:The optimum conditions of inclusion process were as follows:ratio of volatile oil in Menthae Haplocalycis Herba to β-cyclodextrin of 1:10

ratio of β-cyclodextrin to water of 1:3

the inclusion time of 5 min

the rotation speed of 3 000 r·min-1;under these conditions

the average inclusion rate was 96.97% with RSD of 1.0%.TLC

microscopic imaging analysis and FT-IR all proved that the inclusion complex have been formed.GC-MS analysis showed that the components of volatile oil in Menthae Haplocalycis Herba were slightly different before and after inclusion

but the main components and their relative percentage were basically the same. Conclusion:The internal homogenate method for preparing inclusion complex has the advantages of high inclusion rate

time saving

energy saving

etc;and it is suitable for industrial production.It is the potential best method for the preparation of inclusion complex

which needs to be further promoted.