Particle size distribution of concentrated perfluorocarbon emulsions by sedimentation field flow fractionation

Alliance Pharmaceutical Corp's concentrated perflubron (perfluorooctylbromide; PFOB) emulsions are being developed for several medical applications. Sedimentation Field-Flow Fractionation (SdFFF) can provide accurate particle size distribution data when properly calibrated for those emulsions. Since no suitable particle standards are available with the proper density (approximately 1.9 g/cc) and size range (diameter = 0.1-1.0 microns), calibration of the mass distribution was done by comparing the SdFFF detector signal with the actual mass of perflubron extracted from fractions eluted at successive time points and measured by GC. The calibrated mass distribution can then be used to calibrate other instruments such as the photosedimentation instruments used for routine quality assurance measurements.