A New Drug Delivery System (DDS) Developement Using Plasma-Irradiated Pharmaceutical Aids

1.利用Ar等离子体对合成的各种聚合物进行了辐照，探讨了等离子体处理的分子机理，并用电子自旋共振(ESR)技术结合系统的计算机模拟研究了所形成的自由基。通过这个研究项目，我们阐明了粉末聚乙烯(PE)、聚碳酸酯(PC)和肌醇等缩聚聚合物的等离子体诱导表面自由基的性质，以便对各种多糖自由基进行初步研究。以茶碱片剂为核心材料，以PC粉末为单壁材料制备的等离子体辐照双压片的溶出度曲线可以改变，以允许药物以不同的速率释放，这取决于所选择的片剂制造条件和等离子体操作条件。以聚乳酸(PLA)和聚甲醛(POM)为外层的等离子体辐照冻干片可用于皮下组织内植入剂型。外层为具有可交联性侧链的可降解聚合物(甲基丙烯酸苄酯和甲基丙烯酸甲酯共聚物)的等离子体辐照双压片的溶出度分布不仅取决于等离子体的操作条件，还取决于共聚物的组成。结果表明，等离子体辐照PE的机械振动引起了自由基复合反应，导致了粒子间的相互连接。因此，通过等离子体辐照PE和茶碱的机械振动制备的复合粉末的溶出曲线受等离子体辐照PE的自由基浓度控制。希望在目前的工作过程中，能够开发出更多适用于广泛药物和聚合物的装置，以检验等离子体辐照在DDS制造中的有效性。

1. We have undertaken Ar plasma irradiation on a variety of synthetic polymers to explore the molecular mechanism of plasma treatment, and the redicals formed were studied by electron spin resonance (ESR) with the aid of systematic computer simulations. Through this research project, we have elucidated the nature of plasma-induced surface radicals of powdered polyethylene (PE), polycondensed polymer such as polycarbonate (PC) and myo-inositol for an initial study of various polycarbohydrate radicals.2. The dissolution profiles of plasma-irradiated double-compressed tablets prepared from a thephylline tablet as a core material and PC powder as a single wall material can be varied so as to allow release of the drug at different rates, depending on the set of conditions chosen for tablet manufacturing and plasma operational conditions.3. The plasma-irradiated couble-compressed tablets consisting of poy-DL-latic acid (PLA) and polyoxymethylene (POM) as the outer layr can be applied to an implantable dosage form in the subcutaneous tissue.4. The dissolution profiles of the plasma-irradiated double-compressed tablets with the outer layr consisting of a degradable polymer possessing a crosslinkable side chain (benzylmethacrylate and methylmethacrylate copolymer) depends on not only plasma operational conditions but also the copolymer composition.5. It was found that the mechanical vibration of the plasma-irradiated PE caused the radical recombination reaction resulting in the interlinking between the paricles. Thus, the dissolution profile of the comosite powder prepared by the mechanical vibration of the plasma-irradiated PE and theophylline is controlled by the radical concentration of the plasma-irradiated PE.It is hoped that further devices applicable to a wide range of drugs and polymers will be developed in the course of work now in progress to examine the usefulness of plasma-irradiation of DDS fabrications.