Oh Yoon K, Flanagan Douglas R
College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, USA.
PDA J Pharm Sci Technol. 2003 May-Jun;57(3):208-17.
Zein is a hydrophobic corn protein, rich in leucine, proline and alanine, that has has previously been investigated as a potential excipient in pharmaceutical manufacturing. We have investigated the diffusion through or from zein-containing systems and proposed aqueous channels formed by hydration and swelling as the dominant diffusional pathway. In this study, the swelling properties of zein membranes under various conditions and effect of swelling on membrane permeability were investigated. Conditions such as ionic strength and the effect of charged or neutral permeants altered the swelling behavior of zein. Although some permeants (which are highly bound to zein) interact through electrostatic interaction, van der Waals, hydrophobic, and hydrogen bonding interactions, they did not alter membrane swelling behavior significantly. Zein membranes were also cast from different solvent systems but membrane swelling was not affected by casting solvent and the aqueous channels produced in water are independent of membrane preparation. There was no significant permeation difference between different sides of the zein membrane (air or petri dish side). Thus, it appears that zein's permeability largely depends on swelling behavior that is affected by the aqueous ionic content in which it is immersed.
玉米醇溶蛋白是一种疏水性玉米蛋白，富含亮氨酸、脯氨酸和丙氨酸，此前已被研究作为药物制造中的潜在辅料。我们研究了通过含玉米醇溶蛋白体系或从该体系中的扩散情况，并提出水合和溶胀形成的水通道是主要的扩散途径。在本研究中，研究了不同条件下玉米醇溶蛋白膜的溶胀特性以及溶胀对膜渗透性的影响。离子强度等条件以及带电或中性渗透剂的影响改变了玉米醇溶蛋白的溶胀行为。尽管一些渗透剂（与玉米醇溶蛋白高度结合）通过静电相互作用、范德华力、疏水作用和氢键相互作用，但它们并未显著改变膜的溶胀行为。玉米醇溶蛋白膜也由不同的溶剂体系浇铸而成，但膜的溶胀不受浇铸溶剂的影响，在水中产生的水通道与膜的制备无关。玉米醇溶蛋白膜的不同面（空气面或培养皿面）之间没有显著的渗透差异。因此，看来玉米醇溶蛋白的渗透性很大程度上取决于其溶胀行为，而溶胀行为受其所处水相离子含量的影响。
