Figure 2. Schematic of diffusion-partitioning controlled arterial drug uptake and distribution.

(A) Schematic of an excised arterial segment infused with drug solution and both ends were closed. V_lumen is the lumen volume and A_mural is the surface area of the infusate/tissue interface (B) High magnification cross sectional view of the lumen and arterial media, illustrating the key processes and equations governing drug distribution from a well-mixed infusate volume (V_lumen). In the lumen, a fraction f_u, if the drug is free and the remainder is bound to albumin). Only free drug is absorbed by the artery wall. Once in the tissue, free drug diffuses with diffusion coefficient D or binds nonspecifically to tissue proteins with partition coefficient k_p. Drug distribution is dominated by the effective diffusion coefficient D_eff, (Eq. 3) whereas total drug uptake is also governed by the partition coefficient, lumen volume, mural area and the fraction of free drug (Eqs. 1–2).