Imanidis G, Helbing-Strausak S, Imboden R, Leuenberger H
School of Pharmacy, University of Basel, Switzerland.
J Control Release. 1998 Jan 23;51(1):23-34. doi: 10.1016/s0168-3659(97)00125-9.
The possibility of utilizing the interaction between the drug vehicle and the polymeric control membrane of reservoir-type drug delivery systems to modulate the release rate of these systems was investigated. Lipid vehicles common in dermal formulations, with varying composition and viscosity and the Celgard polypropylene membrane were used to study the release of a model drug (salicylic acid). The release kinetics were investigated taking into account two consecutive transport processes, diffusion within the donor reservoir and permeation through the membrane. Membrane permeation was found to be the rate determining step for mass transport and convection appeared to play a significant role in the donor compartment, even though this compartment was not mechanically stirred. The lipid vehicles were imbibed by the membrane, quantitatively replacing the air from its pores. Drug permeation through the membrane was dominated by the vehicle-filled pore pathway, the pathway of the amorphous polymer domain of the membrane generally contributing a small fraction to the total permeation. Permeability coefficients for different vehicles varied within one order of magnitude. This effect was chiefly accounted for by the differences in viscosity of the vehicles occupying the pores of the membrane. Thus, based on the in situ imbibition of the lipid vehicles by the membrane, a controlled variation of the drug release rate could be achieved.
研究了利用储库型药物递送系统的药物载体与聚合物控制膜之间的相互作用来调节这些系统释放速率的可能性。使用了在皮肤制剂中常见的具有不同组成和粘度的脂质载体以及Celgard聚丙烯膜来研究模型药物（水杨酸）的释放。考虑到两个连续的传输过程，即供体储库内的扩散和通过膜的渗透，对释放动力学进行了研究。发现膜渗透是质量传输的速率决定步骤，并且对流似乎在供体隔室中起重要作用，尽管该隔室没有进行机械搅拌。脂质载体被膜吸收，定量地取代了其孔隙中的空气。药物通过膜的渗透主要由充满载体的孔隙途径主导，膜的无定形聚合物区域的途径通常对总渗透贡献很小一部分。不同载体的渗透系数在一个数量级内变化。这种效应主要是由占据膜孔隙的载体粘度差异引起的。因此，基于膜对脂质载体的原位吸收，可以实现药物释放速率的可控变化。
