Effect of Medium on Partition and Diffusion of Drugs in Polymeric Membranes

藥物溶媒對藥物在高分子膜中分配及擴散之影響

王大銘(Da-Ming Wang) ； 朱純瑩(Chwen-Yen Chu) ； 吳淑婷(Shu-Ting Wu) ； 賴君義(Juin-Yih Lai)

《Journal of the Chinese Institute of Chemical Engineers》 33卷6期 (2002/11) Pp. 555-563

https://doi.org/10.6967/JCICE.200211.0555

摘要

本研究之主要目標係探討藥物溶媒對藥物在高分子膜中分配及擴散的影響。實驗中所採用的溶媒為乙醇水溶液，可調整其濃度來改變溶媒性質；所研究的高分子膜為在乙醇水溶液中具完全不同膨潤特性的三種膜poly(ethylene-co-vinylacetate)、poly(ethylene-co-vinylalcohol)及Nylon-4；而所選用的藥物有疏水性藥物benzocaine及親水性藥物theophylline。結果顯示可透過改變溶媒的性質來調整藥物在高分子膜中的透過性。藉由溶解－擴散模式可將溶媒的效應分為對藥物在膜中分配係數及擴散係數的影響，此二效應相互加成或競爭決定藥物透過性隨溶媒性質的變化情形。溶媒性質對藥物擴散係收的影響，可用其對膜的膨潤度來解釋，更可進一步利用Yasuda模式來進行定量描述。而關於溶媒對分配係數的影響，對benzocaine而言，其在溶媒中的溶解性質主導分配係數的變化，但對theophylline，並找不到簡單的關聯性。

並列摘要

Data are reported in the present work to add to our understanding of the effect of medium (drug solvent) on drug partition and diffusion. The medium used was ethanol-water solution of which the property can be changed by adjusting the ethanol concentration. The membranes used included poly(ethylene-co-vinylacetate) (EVAc), poly(ethylene-co-vinylalcohol) (EVAL) and Nylon-4, three membranes with distinctly different swelling characteristics. The model drugs were benzocaine, a hydrophobic drug and theophylline, a hydrophilic drug. The results indicate that the drug permeability through the polymeric membrane can be adjusted by varying the property of the medium. By using the solution-diffusion model, the effect of the medium on the drug permeability can be decomposed into two parts: the effect on the partition coefficient and the effect on the drug diffusivity. The interplay between partition and diffusion determines the dependence of the drug permeability on the property of the medium. The effect on the drug diffusivity can be well correlated with the membrane swelling characteristics, and the Yasuda model can give a reasonable quantitative description for the dependence of the drug diffusivity on the swelling ratio. For the hydrophobic drug benzocaine, the effect of the medium on the partition coefficient is meanly dominated by its effect on the drug solubility. On the other hand, for the hydrophilic drug theophylline, the effect of the medium on the partition coefficient is much more complicated.

並列關鍵字

Drug transport ； Swelling ； Diffusion ； Partition ； Polymeric membrane