Effect of Different Penetration Enhancers on the Transdermal Permeation of Diclofenac Potassium Gel in Vitro

OBJECTIVE: To study the effects of Azone,propylene glycol(PG),oleic acid(OA) alone or in combination of two or three as penetration enhancers on the in vitro transdermal efficacy of diclofenac potassium(DP) gels.METHODS: Thirteen formulations of DP gels containing the following different penetration enhancers at different concentrations were prepared: blank,3% Azone, 5% OA,12% PG,6% PG+2.5% OA,12% PG+5% OA,1.5% Azone+2.5% OA,1.5% Azone+6% PG+5% OA,1.5 % Azone+12% PG,3% Azone+5% OA,3% Azone+6% PG,3% Azone+6% PG+5% OA,and 3% Azone+12% PG.The in vitro permeation test was performed on a modified Franz-type diffusion cell with human skin as transdermal barrier taking transdermal velocity(J) as index to determine and compute the transdermal properties of the DP gels after treated respectively by the above 13 penetration enhancers.RESULTS: Compared with the blank control group,all the penetration enhancer-treated formulations showed significant higher J value,with the formulation treated by 3% Az-one+12% PG enhancer showing the highest J value of 10.253 0 μg·cm-2·h-1.CONCLUSION: All the three penetration enhancers could promote the transdermal permeation DP gels,much as in the combination of Azone and propylene.