Theeuwes F
J Pharm Sci. 1975 Dec;64(12):1987-91. doi: 10.1002/jps.2600641218.
The elementary osmotic pump is a new delivery system for drugs or other active agents; it delivers the agent by an osmotic process at a controlled rate. Control resides in the: (a) water permeation characteristics of a semipermeable membrane surrounding the formulated agent, and (b) osmotic properties of the formulation. In its simplest embodiment, the system is constructed by coating an osmotically activie solid agent with the rate-controlling, semipermeable membrane. This membrane contains an orifice of critical size through which solubilized agent is dispensed. The system can contain the agent in solid form at loading higher than 90% of the total volume, and the agent can be delivered at rates several orders of magnitude higher than can be achieved by solution diffusion through polymeric membranes. The delivery rate, the fraction of total content delivered at zero order, and the system's delivery portal size have been calculated for delivery of a single compound. Experimental work verified the theory. The release rate from the system was found to be independent of outside agitation when the system is not deformed by shaking action, the pH of the environment, and delivery portal size for sizes within a specified range. The delivery rate from this system in vitro and in the GI tract of dogs was found to be equal.
基本渗透泵是一种用于药物或其他活性剂的新型给药系统；它通过渗透过程以可控速率输送活性剂。控制因素在于：(a) 包裹制剂的半透膜的水渗透特性，以及 (b) 制剂的渗透性质。在其最简单的形式中，该系统通过用控速半透膜包裹渗透活性固体剂来构建。该膜包含一个临界尺寸的孔口，溶解的活性剂通过该孔口释放。该系统可以以高于总体积90%的载量以固体形式包含活性剂，并且活性剂的释放速率比通过聚合物膜的溶液扩散所能达到的速率高几个数量级。对于单一化合物的释放，已经计算出了释放速率、零级释放的总含量分数以及系统的释放孔口尺寸。实验工作验证了该理论。当系统不因摇晃作用而变形时，发现该系统的释放速率与外部搅拌、环境的pH值以及特定范围内尺寸的释放孔口尺寸无关。该系统在体外和犬胃肠道中的释放速率是相等的。
