正极性驻极体环孢菌素A贴剂的开路热刺激放电

Open Thermally Stimulated Discharge of Positive Electret Cyclosporine A Patch

为了研究驻极体环保菌素A贴剂的透皮给药机制,利用药剂学技术制备了环孢菌素A贴剂,通过栅控恒压电晕充电系统将聚丙烯（PP）薄膜制备成初始表面电位为500 V和1 000 V的驻极体,并将环孢菌素A贴剂与驻极体复合后得到了驻极体环孢菌素A贴剂。借助于开路热刺激放电（TSD）技术研究了不同初始表面电位的驻极体对环孢菌素A贴剂的热释电特性。结果显示：①环孢菌素A贴剂中基质和模型药物分子处于弱极性和非极性状态,其开路TSD电流谱中出现相应的弱小低温偶极峰群、高温偶极峰群和空间电荷峰;②不同初始表面电位的正极性驻极体能提供稳定的外静电场以作用于环孢菌素A贴剂,500 V驻极体作用时间为10 h时,环孢菌素A贴剂的40-60℃低温偶极电流峰迁移至40-70℃温区,且峰形展宽和峰值相应增加;③随着驻极体作用时间的延长和作用电压的增加,驻极体外电场能使更多的环孢菌素A贴剂内极化分子分子极化程度增加并沿外电场方向排列取向。可得结论：驻极体可引起环孢菌素A的极化,环孢菌素A的极化程度随驻极体外静电场及作用时间的增加而加强,驻极体可实现对环孢菌素A贴剂中的模型药物的可控释放。

To evaluate the transdermal mechanism of electret cyclosporine A patch, we tested the impact of polypropylene（PP） electrets＇ voltage on the thermal discharge properties of cyclosporine A patches based on the open thermally stimulated discharge（TSD） method. The tested patches were prepared by coupling polypropylene（PP） electrets, in which PP films were charged to 500 V or 1 000 V by a grid-controlled constant-voltage corona charging system, with cyclosporine A patch. Results drawn from the tests are as follows： （1）There are weak dipole peaks at both low and high temperatures, as well as weak space charge peaks at high temperatures in the TSD spectra of cyclosporine A patch, indicating model drug and matrix in the patches are in nonpolar state and weak-polar state, respectively. （2）Electrets with different positive voltages are able to sustain stable electrostatic field on the patches. For the patches treated by 500 V electrets for 10 hours, the dipole peaks at low temperatures（40-60 ℃） shift to high temperatures（40-70 ℃）, and their width and amplitude both increase after treatment of the drug patch by 500 V electret for 10 hours. （3）With increased treatment duration and voltage, electrostatic field from electrets enhances the polarization and orientation of more drug molecule. It is concluded that compounding electrets to cyclosporine A patches can successfully induce the polarization of cyclosporine A that intensifies increasing intensity and treatment duration of the external electrostatic field, and in this way it is able to realize controlled release of the model drugs.