HYDROLYSIS KINETIC-STUDY OF ASPIRIN IN MICROEMULSIONS

The hydrolysis kinetics of aspirin in micro emulsion system for cetylt rimethylammonium bromide (CTAB)/n - butanol/25% n - octane/water was s tudied by using UV method, and the mechanism of the hydrolysis was dis cussed. The results show that the hydrolysis was affected by the struc ture and the structural transition of microemulsions. The hydrolysis r ates are higher in W/O microemulsion media and decrease with the addit ion of water, they increase with that in B.C., and they decrease with that in O/W. The transition points of the hydrolysis rates occur at th e points of the structural transition from W/O to B. C., and B.C. to O /W, and this was considered to be caused by the different hydrolysis m echanism and the change of polarity in interfacial films.