Abstract
The transport of steroid hormones was investigated for a liquid membrane system using bovine serum albumin (BSA) as the carrier that separated the hexane source phase from the hexane receiving phase. The experimental results could be adequately explained by a model in which hormones are transferred from the hexane source phase to the water membrane for binding with BSA and then transported through the membrane in both BSA-bound and free forms. Based on the results of analysis, the dynamic parameters for transport were determined. For a hormone with a lower water/hexane partition coefficient, the uptake from the hexane source phase to the water phase was one of the rate-determining steps in the transport and hormone transport was accelerated by the addition of BSA. The release process from the water phase to haxane receiving phase is the rate-determining step when the partition coefficient is high. Transport is thus governed by concentration of the hormone in the free form on the water membrane and hormone transport is decelerated by the addition of BSA, since the concentration of the free form decreases inversely by association with BSA for the system in which the amount of hormone in the hexane source phase is limited.
