Benedikt G, Steinijans V W, Dietrich R
Department of Galenical Development, Byk Gulden Research Center, Konstanz, Fed. Rep. of Germany.
Arzneimittelforschung. 1988 Aug;38(8A):1203-9.
Euphylong is a sustained-release product consisting of encapsulated pellets covered with a porous membrane. Since the mechanism of release is osmotic, this new formulation has been termed a "micro-osmotic system". The course of theophylline release is linear over a wide range and is independent of pH value, surface tension and buffer concentration of the dissolution medium. Furthermore, the in-vitro release remains largely uninfluenced by the dissolution model used and by agitation of the dissolution medium. Variations in the in-vitro release profiles produce variations in the in-vivo absorption profiles determined by deconvolution. It is therefore possible, irrespective of the dissolution model and medium used, to produce in-vitro release profiles that enable in-vivo absorption to be predicted by varying the thickness or porosity of the membrane.
优菲龙是一种缓释产品，由包裹着多孔膜的包衣小丸组成。由于释放机制是渗透作用，这种新剂型被称为“微渗透系统”。茶碱的释放过程在很宽的范围内呈线性，且与溶出介质的pH值、表面张力和缓冲液浓度无关。此外，体外释放很大程度上不受所用溶出模型和溶出介质搅拌的影响。体外释放曲线的变化会导致通过反卷积确定的体内吸收曲线发生变化。因此，无论使用何种溶出模型和介质，都可以通过改变膜的厚度或孔隙率来产生能够预测体内吸收的体外释放曲线。
