PLURONIC 68, A COPOLYMER OF ETHYLENE OXIDE-PROPYLENE OXIDE, IS THE SURFACTANT MOST THOROUGHLY STUDIED FOR STABILIZING PERFLUOROCHEMICAL EMULSIONS USED AS INTRAVENOUS OXYGEN TRANSPORT FLUIDS; IT EXHIBITS ADVANTAGEOUS CHEMICAL AND EMULSIFICATION PROPERTIES

PLURONIC 68, A COPOLYMER OF ETHYLENE OXIDE-PROPYLENE OXIDE, IS THE SURFACTANT MOST THOROUGHLY STUDIED FOR STABILIZING PERFLUOROCHEMICAL EMULSIONS USED AS INTRAVENOUS OXYGEN TRANSPORT FLUIDS; IT EXHIBITS ADVANTAGEOUS CHEMICAL AND EMULSIFICATION PROPERTIES BUT TESTS HAVE SHOWN SOME LOTS OF THE POLYMER TO BE MILDLY TOXIC. MANY TYPES OF PURIFICATION AND FRACTIONATION PHILOSOPHIES, E.G., ADSORPTION (BOTH IONIC AND NONIONIC SUBSTRATES), SOLVENT-ANTISOLVENT PRECIPITATION, ETC., HAVE BEEN DIRECTED TO THE PROBLEM WITH VARYING RESULTS. SUPERCRITICAL FLUID SOLVENTS, I.E., GASES AT CONDITIONS ABOVE THEIR RESPECTIVE CRITICAL POINTS, EXHIBIT PRESSURE-DEPENDENT DISSOLVING POWER PROPERTIES AND THE ABILITY TO DISSOLVE SELECTIVELY ONE OR A FEW COMPONENTS IN A MIXTURE CAN BE CONFERRED TO THEM BY VIRTUE OF APPLIED PRESSURE. DATA ARE PRESENTED IN THE WORK PLAN ON THE FRACTIONATION AND PURIFICATION OF THREE REFRACTORY AND LABILE POLYMERS, AND THE METHODOLOGY USING SUPERCRITICAL SOLVENTS IS EXTENDED TO THE PLURONIC 68 POLYMER. A RESEARCH PROGRAM WHICH MEASURES SOLUBILITY, DETERMINES FRACTIONATION CHARACTERISTICS, VERIFIES MOLECULAR WEIGHT RANGES AND POLYDISPERSITY BY VISCOSITY AND GEL PERMEATION CHROMATOGRAPHY, AND EVALUATES TOXICITY BY WHITE CELL AGGREGATION TESTING IS DESCRIBED. BECAUSE THE PROBLEM OUTLINED IS A CURRENT AND REAL ONE FACING RESEARCHERS, SUPPLIERS, AND THE EVENTUAL SUBJECTS BEING ADMINISTERED THE OXYGEN CARRIERS, AND BECAUSE THESE OXYGEN CARRIERS HAVE USES FARTHER REACHING THAN SURGERY FLUIDS, SUCCESSFUL DEMONSTRATION OF THE ABILITY OF SUPERCRITICAL FLUID SOLVENTS TO PRODUCE FRACTIONS DEVOID OF TOXICITY PROBLEMS WOULD WARRANT A PHASE II STUDY. FURTHERMORE, THE DEMONSTRATION THAT THE FRACTIONS ARE REPRODUCIBLE AND OFFER REASONABLE ECONOMICS WILL BE STRONG INDUCEMENT TO CARRY THE STUDY FROM THE LABORATORY TO A COMMERCIAL PHASE.