Which statement about iron dextran's destabilizing effect on emulsions is true?

Which statement about iron dextran's destabilizing effect on emulsions is true?

• A. Iron dextran destabilizes emulsions due to Fe3+ valence
• B. Iron dextran stabilizes emulsions
• C. Iron dextran has no effect
• D. Iron dextran improves miscibility

Answer: (A)

Multivalent metal ions can destabilize emulsions by changing the interfacial charge and promoting droplet interactions. Iron dextran provides ferric ions with a +3 charge, which strongly screens the electrostatic repulsion between droplets and can bridge charged sites on different droplets or at the emulsifier, lowering the zeta potential and encouraging flocculation and coalescence. This leads to destabilization. So, the destabilizing effect is due to the Fe3+ valence. It does not stabilize the emulsion, it does have an effect, and it does not improve miscibility.

Multivalent metal ions can destabilize emulsions by changing the interfacial charge and promoting droplet interactions. Iron dextran provides ferric ions with a +3 charge, which strongly screens the electrostatic repulsion between droplets and can bridge charged sites on different droplets or at the emulsifier, lowering the zeta potential and encouraging flocculation and coalescence. This leads to destabilization. So, the destabilizing effect is due to the Fe3+ valence. It does not stabilize the emulsion, it does have an effect, and it does not improve miscibility.