, and represents the permeability coefficient for compounds from aqueous solution to aqueous solution through the membrane. the natural breakpoints needed to integrate Eq. 4, splitting the overall permeation process into crossing and adsorption/desorption components. Together with the partition coefficient, these elements together can be combined following prior literature to obtain an effective permeability coefficient (P m e , Table ) that quantifies the flux across a membrane from the inside to the outside of a cell given a concentration gradient across the membrane.