Differences in the coalescence kinetics of fat emulsions in dependence on the amount of fat and age.
The destabilizing effect of calcium ions on emulsions was studied as a function of the age of the emulsions and the degree of emulsion dilution (2%, 0.2% an 0.02% fat). Particle size measurements were performed both in the Coulter counter and a laser diffraction device equipped with PIDS technology. The data of both instruments showed a good correlation. zeta-Potential was determined by laser doppler anemometrie. The physical stability of the emulsions in 6 mmolar Calcium Chloride decreased with increasing dilution--despite the diminished rate of collision in diluted systems. In addition, and increased electrolyte sensitivity was observed with increasing age of the emulsions--despite enhanced electrostatic stabilization by an increased zeta-potential. Both effects were attributed to an increased binding of calcium ions per surface area of the droplets, i.e. increased ratio calcium ions to surface by dilution and increased binding by the increased charge of aged emulsions.
Harnisch
S
S
Department of Pharmaceutics, Biopharmaceutics and Biotechnology, Free University of Berlin, Germany.
Schuhmann
R
R
Harnisch
J F
JF
Müller
R H
RH
D004041:Dietary Fats / Q000032:analysis*; D004355:Drug Stability; D005217:Fat Emulsions, Intravenous / Q000737:chemistry*; D007700:Kinetics; D007834:Lasers; D010316:Particle Size; D012996:Solutions; D013997:Time Factors
D004041:Dietary Fats; D005217:Fat Emulsions, Intravenous; D012996:Solutions