PT  - JOURNAL ARTICLE
AU  - Yoon K. Oh
AU  - Douglas R. Flanagan
TI  - Swelling and Permeability Characteristics of Zein Membranes
DP  - 2003 May 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 208--217
VI  - 57
IP  - 3
4099  - http://journal.pda.org/content/57/3/208.short
4100  - http://journal.pda.org/content/57/3/208.full
SO  - PDA J Pharm Sci Technol2003 May 01; 57
AB  - Zein is a hydrophobic corn protein, rich in leucine, proline and alanine, that has has previously been inves-tigated 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.