Interaction of Hexachlorophene with Human Epidermis I: In Vivo Bioelectrometric Study of Ph Influence

Drug—Biomolecule Interactions: Bioelectrometric Study of the Mechanism of Carbachol Interactions with the Cornea and its Relation to Miotic Activity

“…This same behavior has also been observed in this laboratory with titration curves obtained in uiuo on rabbit intestinal mucosa and frog skin. Less physiologically active tissue surfaces such as epidermis and connective tissue, which do not actively transport ions across their single or multicellular barriers, exhibit this effect to a minor degree or not a t all (5,7,15).…”

“…The composition of the carbachol-free buffer solutions employed in the p H titration experiments was reported earlier (5). Carbachol solutions8 were prepared by the addition of carbachol to pH 6.95 phosphate buffer solutions.…”

“…Bioelectrometric Methodology--The previously described dilution potential method (3)(4)(5)15), as contrasted to an equilibrium method or the dilution-potential-time extrapolation method (11), was utilized to determine the dependency of the fixed charge density of the corneal surface on the composition of applied experimental solutions. The fixed charge density arises from the dissociation of ionogenic groups covalently bonded to or sorbed onto the biocolloids constituting the tissue surface (14).…”

Electrometric Determination of the Fixed-Charge Density of Colloid Surfaces: Further Confirmation of the Method

“…It permits tissue surfaces to be studied under normal physiological or product use conditions. It has been applied to the elucidation of the electronic mechanisms of drug tissue interactions (3)(4)(5) and their characterization in terms of thermodynamic and kinetic parameters (1-7); it is useful for the determination of equilibrium sorption isotherms (5, 7) and the study of the kinetics of solute sorption and desorption from in uiuo tissue surfaces (7). When experimentally feasible, electrometric results were confirmed by more conventional techniques (5-7).…”

“…Electrometric Determination of Fixed-Charge Density of the Membrane-Details of the dilution potential method for the determination of the fixed-charge density of colloid surfaces were previously reported (1)(2)(3)(4)(5)(6). The in uitro measurements were performed in a manner analogous to the in uiuo procedure.…”