摘要
In previous studies, compound mefformin/glipizide was developed. Aim To discover the mechanism of drug release from factors influencing drug release from dosage form （the semi-permeable cry orifice） were investigated. Results The influx of water that elementary osmotic pump tablet it. Methods Three rate-limiting membrane, tablet core and delivpassed the osmotic pump tablet was almost equal to the metformin release rate, while it was greatly less than the drug dissolution rate from tablet core. The size of orifice from 0. 4 mm to 0.8 mm had no influence on drug release. The osmotic pressure of tablet core was mainly caused by mefformin. Conclusion From the developed model of osmotic pump systems, it can be seen that only the water influx through the membrane is a rate-limiting step, not tablet core dissolution rate and solution influx, and only when the core dissolution rate is equal to the solution influx, the zero order release is seen in the osmotic pump systems.
目的在以前的实验中研制了复方二甲双胍/格列吡嗪单室渗透泵片,但是其释药机理没有阐明。方法在本文中,主要考察了可能影响药物释放的三个限速因素(半透膜,片心和释药孔)。结果研究发现单位时间内透进渗透泵的水量同二甲双胍的释放速率基本相当,但远小于片心的溶出速率;孔径从0·4到0·8毫米对药物释放无显著影响;片心的渗透压主要由二甲双胍产生。结论从渗透泵系统的数学模型来看,主要限速步骤在于单位时间透过半透膜的水量,不是片心溶出速率和溶液从小孔的释放速率,片心的溶出速率同溶液从小孔的释放速率相等,因此渗透泵系统表现出零极释放。
