随着科学技术的发展,人类需要使用愈来愈多的药物与试剂等各种具有化学与生物活性的物质,来达到预定的目的。然而,在使用药物与试剂的过程中,人们发现,传统的使用方式存在不少缺点,它不仅浪费了药剂,产生了危害人类及环境的副作用,而且也达不到人们理想的效果。例如医生用药物给病人治病,希望药效能维持数天、数星期或更长的时间,直至病人恢复健康为止,但按照传统方式用药,总是一次投入大剂量,大大超过药物的有效浓度,即产生药效的 With the development of science and technology, human beings need to use a growing number of drugs and reagents and other chemical and biological activity of substances, to achieve the intended purpose. However, during the use of drugs and reagents, people find that there are many disadvantages in the traditional methods of use. They not only waste medicaments, have side effects that harm people and the environment, but also fail to achieve the desired effect. For example, doctors treat patients with drugs and hope that their efficacy will last for several days, weeks or longer until the patients resume their health. However, according to the traditional method, the drugs are administered once in large doses and greatly exceed the effective concentration of the drugs , That produce efficacy