Evaluation of penetration enhancement of lidocaine by porous PTFE/PE/PP electret through mouse skin in vitro

The main object of this study was to systemically evaluate the effect of porous PTFE/PE/PP electret on lidocaine transdermal delivery and to compare its enhancing effect with some commonly used chemical permeation enhancers, that is propylene glycol, oleic acid and menthol. The composite electret was prepared by heat melting method at 130□. The modified Franz diffusion cell was used to carry out the in vitro permeation experiment and a high performance liquid chromatography (HPLC) was employed to analyze the drug concentration. The drug solution containing no chemical permeation enhancer or no electret application was taken as control group. The results indicated that: (1) The feasibility of using porous PTFE/PE/PP electret to enhance the lidocaine transdermal delivery was achieved by applying positively charged electrets with different surface potentials. The enhancing effect was proportional to the surface potential of the electret. (2) The chemical permeation enhancers used were shown to be less effective than the +1000 V electret on lidocaine transdermal permeation. The 24 hour´s cumulated permeation amount of lidocaine reached to 3.649, 6.029, 8.619, 6.330 and 17.218 mg for control group, 10% oleic acid, 20% propylene glycol, 1% menthol and porous PTFE/PE/PP electret, respectively. In conclusion, positively charged electret can be used as the enhancer to increase the transdermal permeation of lidocaine.