OBJECTIVE:To investigate the property,skin irritation and in vitro transdermal absorption of Diclofenac sodium microemulsion(DS-ME),and to explore the feasibility of local external use of it. METHODS:The content of DS in DS-ME was determined by ultraviolet spectrophotometry. The distribution of particle size was determined by laser particle size analyzer. The ef-fects of DS-ME and blank micro-emulsion on normal skin of single administration,normal skin of multiple administration and dam-aged skin of single administration were investigated by rabbit skin irritation test. The transdermal parameters of DS-ME and commer-cially available DS gel through isolated skin of mice were compared by Franz diffusion cell. RESULTS:The prepared DS-ME was O/W microemulsion with particle size of(30.140±9.020)nm. Compared with blank ME,DS-ME had no significant difference in rabbit skin irritation score. Steady permeation rates of DS-ME and commercially available DS gel were 34.16 and 18.62 μg/(cm2·h), respectively;the permeation coefficient of them were 1.029 and 0.561 cm/h;the delay time were 0.124 2 and 0.367 2 h. CONCLU-SIONS:The particle size of DS-ME is small and not irritant to skin,and can improve transdermal absorption rate of DS.

OBJECTIVE:To research the mechanism of in vitro permeation of phillyrin through blood-brain barrier. METH-ODS:After Madin-Darby canine kidney epithelial cells transfected with colorectal cancer MDR1 gene (MDCK-MDR1) were cul-tured with phillyrin solution of 0(negative control),10,25,50,75 and 100μg/ml for 24 h,cell viability was determined by resa-zurin method and cell survival rate was calculated. After MDCK-MDR1 cells were cultured with phillyrin solution of 10,25,50, 75 and 100 μg/ml for 10 min,the content of phillyrin in the cells was determined,and concentration-uptake rate curve was drawn. Following 3 h culture of MDCK-MDR1 cells with phillyrin solution of 0 (negative control),50 and 100 μg/ml,the structure of cell tight junction protein was observed under the inverted microscope. RESULTS:Compared to the negative control group,after 24 h cell culture with phillyrin solution of 10-100 μg/ml,no obvious change in cell survival rate occurred. MDCK-MDR1 cells cultured with the phillyrin at a mass concentration of 10-100 μg/ml demonstrated a nonlinear relationship with concentration of phillyrin and a gradual saturation trend. After the cells were cultured with phillyrin of 50 and 100 μg/ml for 3 h,cell tight junction protein was intact. CONCLUSIONS:The absorption of phillyrin through the simulated blood-brain barrier may be in the form of passive transportation combined with active transportation,the concertration has effect on cell tight junction protein.