Determination of the pH-dependent phase distribution of prostaglandin E1 in a lipid emulsion by ultrafiltration

摘要: The distribution of prostaglandin E1 (PGE1) in a lipid emulsion has been shown to be consistent with three-phase model which assumes that solute may reside the bulk aqueous and oil phases at oil/water interface. Calculations suggest that, having an average particle size 0.11 µm, it is theoretically possible for surface active species such as PGE1 exist predominantly Aqueous phase concentrations versus pH were measured volume ratio 0.1 by use ultrafiltration technique order estimate relative percentages PGEl each phase. From partition coefficient determinations, amount present was concluded insignificant. At values less than 5, resides preferentially (>97%) With increasing pH's, percentage increases, reaching 51% high pH's. A both nonionized ionized interface, depending on pH, data. Estimates made coefficients between interface their concentration dependence. apparent pKa derived from these data 6.8. used generate profile various PGE1, function pH. This will useful explaining kinetic