Siegel I A
Arch Oral Biol. 1984;29(1):13-6. doi: 10.1016/0003-9969(84)90036-0.
The permeability of the oral mucosa to organic solutes of different molecular volumes, oil-to-water distribution coefficients, and pKa was studied in an in-vivo system. The calculated permeability coefficients were independent of time of application and the concentration of the solutes, a finding consistent with transport by simple diffusion. The permeability of organic acids was pH dependent whereas permeability to compounds with a degree of ionization that did not change over the pH range was not affected by pH. Increasing the chain length from two to eight carbons in an organic acid series resulted in an increase of both the oil-to-water distribution coefficient and the permeability coefficient; the permeability coefficient was decreased by the addition of oxygen in the form of hydroxyl groups. These results indicate that there is similarity in the way that lipid-soluble substances diffuse across oral mucosa and other lipid membranes. Results using compounds with oil-to-water distribution coefficients less than that of water suggest that these compounds traverse the oral mucosa by two additional routes. One, for compounds with molar volumes less than 80 cm3/ml, is via pores; whereas, the second, utilized by larger compounds, is probably by an intercellular route.
在一个体内系统中研究了口腔黏膜对不同分子体积、油水分配系数和pKa的有机溶质的渗透性。计算得到的渗透系数与应用时间和溶质浓度无关，这一发现与简单扩散运输一致。有机酸的渗透性取决于pH值，而在整个pH范围内电离程度不变的化合物的渗透性不受pH值影响。在有机酸系列中，将链长从两个碳原子增加到八个碳原子会导致油水分配系数和渗透系数都增加；以羟基形式添加氧会降低渗透系数。这些结果表明，脂溶性物质跨口腔黏膜和其他脂质膜扩散的方式具有相似性。使用油水分配系数小于水的化合物的结果表明，这些化合物通过另外两条途径穿过口腔黏膜。一条途径是，对于摩尔体积小于80 cm3/ml的化合物，是通过孔隙；而第二条途径，被较大的化合物利用，可能是通过细胞间途径。
