聚四氟乙烯微针模具的性能考察

目的:考察用聚四氟乙烯(PTFE)制作相转化水凝胶微针模具的性能。方法:聚四氟乙烯模具经过粉末的过筛、压制、烧结、制孔而得。实验制备了不同聚四氟乙烯粉料粒度、不聚四氟乙烯粉料用料量、不同生料板压制压力的聚四氟乙烯微针模具,向模具中浇注以PVA为基质的聚合物溶液,通过冷冻解冻制得相转化水凝胶微针,考察模具的孔径、载料量以及微针的揭膜难易程度和完形率。结果:80目以上细度的模具透光性能均一;随着聚四氟乙烯用料量的增加和生料板压制压力的增大,模具的孔径和载药量减小,揭膜更容易、完形率更高。结论:聚四氟乙烯模具的性能与其密度密切相关,密度越大的模具,蠕变的随意性越大,因而孔洞均一性下降,但是揭膜性能变好,完形率提高。这两个相反的趋势提示我们,四氟乙烯模具的优劣是相转化水凝胶微针中的第一个控制性因素,聚四氟乙烯是制作微针模具的可接受材料,有进一步研究的价值。

Performance Study of PTFE Microneedle Molds

Objective:To investigate the performance of phase-transition microneedle molds made of polytetrafluoroethylene (PTFE).Methods:PTFE microneedle molds are made after sieving, pressing, sintering, and punching microneedle holes. PTFE molds with different powder sizes, weight of PTFE, pressure of making PTFE plate were made. Polymer solutions with PVA as the main material were poured into the molds. Phase-transition microneedles were made in order to investigate the diameter of microneedle holes, the weight of solution loaded in the molds, the easiness of peeling the microneedle patches off the molds, and the rate of good microneedles.Results:Molds make of PTFE powder after over 80 mesh sieving showed uniform light transmission properties; with the increasing of PTFE weight and the pressure of making PTFE plates, the diameter of the microneedle holes and the weight of solutions loaded decreased, while the easiness of peeling the microneedle patches off the molds and the rate of good microneedles were improved.Conclusion:The performance of PTFE mold is highly related to its density. The randomness of creep gets bigger with the increasing of density, and therefore the uniformity of holes in the mold decreases, while the easiness of peeling the microneedle patches off the molds and the rate of good microneedles are improved. These two opposing trends remind us that PTFE mold is the first controlling factor for making phase-transition microneedles. PTFE is one kind of acceptable materials to make microneedle molds and deserves further study.