Rheological properties of phospholipid-stabilized parenteral oil-in-water emulsions - effects of electrolyte concentration and presence of heparin
2003 (English)In: Internation Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 252, no 02-jan, 123-132 p.Article in journal (Refereed) Published
The rheological properties of the parenteral oil-in-water emulsion Intralipid(TM) were investigated. The viscosity data at different phase volumes correlated well with that obtained via a theoretical model developed by Yaron and Gal-Or. The model also describes the temperature dependence well. The effects of electrolyte addition were also investigated. Monovalent sodium chloride had practically no influence on viscosity. Calcium chloride, on the other hand, had a large impact on viscosity even at low concentrations. It was shown that the obtained maximum in viscosity coincided with the zeta-potential being close to zero. The resulting increase in viscosity is due to flocculation that leads to an increase in apparent phase volume. A similar behaviour was obtained with magnesium chloride with the difference that the maximum in viscosity was shifted to higher electrolyte concentrations. This is interpreted as that because magnesium binds strongly to the hydration water than does calcium. The addition of the negatively charged anti-coagulant heparin causes flocculation in the presence of small amounts of calcium. The amounts of calcium needed for such bridging flocculation is lower than what is needed in order to create a positive potential at the surfaces of the droplets. A fraction of the floes is not broken down even by extensive shear.
Place, publisher, year, edition, pages
2003. Vol. 252, no 02-jan, 123-132 p.
rheology, viscosity, Intralipid (TM), specific adsorption, bridging flocculation, emulsion, intravenous fat emulsions, electrokinetic properties, vesicles, nutrition, binding, calcium
IdentifiersURN: urn:nbn:se:kth:diva-22260ISI: 000181050900012OAI: oai:DiVA.org:kth-22260DiVA: diva2:340958
QC 201005252010-08-102010-08-10Bibliographically approved