藥物溶解速率及邊界層阻力對藥物釋放之影響

本研究探討藥物以擴散方式於平板和球型基質載體系統中之釋放，並以數值方法解析載體中液態及固態藥物濃度分布和藥物累積釋放率的變化。探討的變數包括有無因次藥物溶解常數(K)、無因次藥物飽和溶解度(CS)、藥錠中初始液態藥物濃度(C0)、及無因次Biot number(Bi=kcR/D)等。計算結果顯示當K=1時，固體藥物於載體中之分布較為均勻，其藥物濃度隨位置的分布曲線接近水平，隨著K值逐漸增加，固體藥物濃度分布曲線逐漸轉為接近梯形的曲線；CS對藥物分布的影響，發現不論為完全沉浸或具邊界層質傳阻力之邊界條件，當CS增加時，藥物釋放速率增大。在含有質傳阻力層的探討中，固體藥物及液體藥物濃度分布趨勢與完全沉浸系統之結果差異不大，而釋放累積率則受到阻力層影響而有降低。當Bi=1時，藥物釋放累積率十分緩慢，且於開始的時候有較長的延遲時間，藥物釋放累積率達99%之時間也延緩許多。

關鍵字

完全沉浸邊界條件；質傳阻力邊界條件；藥物控制釋放；基質型載體；擴散

並列摘要

In this study, the release of drug from planar or spherical matrix by diffusion was investigated, and the profiles of solid and liquid drug concentration in the matrix and the amount of drug release curve were obtained by numerical calculation. The parameters include the dimensionless drug dissolution constant (K), dimensionless saturated dissolution concentration of drug in matrix (CS), initial liquid drug concentration in matrix (C0), and the Biot number (Bi). The calculated results show that when K=1, the distribution of solid drug in the matrix is more uniform, and the variation of solid drug concentration in radial direction is slight. The concentration profile approaches to the trapezoid form when the value of K increases. The release rate increases with increasing CS in the condition of perfect sink or with boundary layer resistance. In the condition with mass transfer resistance or perfect sink, the concentration profiles of solid or liquid drug is similar. However, the release rate decreases as the mass transfer resistance increases. When Bi=1, the release has a significant time lag, the release rate is small and the time for 99% releasing is longer.

並列關鍵字

Perfect sink condition ； Boundary layer resistance ； Matrix system ； Drug controlled release ； Diffusion

參考文獻

24. Y. S. Lin, R. Y. Tsay, “The effects of finite dissolution rate on the drug release of spherical particles loaded with uniformly dispersed drugs”, Journal of the Chinese Institute of Chemical Engineers, 35 (2004) 667

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國際替代計量

藥物溶解速率及邊界層阻力對藥物釋放之影響

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