Physical compatibility of MCT/LCT propofol emulsions with crystalloids during simulated Y-site administration.

Objective: In intensive care units numerous drugs have to be infused simultaneously, resulting inline incompatibility. Propofol is formulated as a lipid emulsion and it is well known that electrolytes can affect the stability of an emulsion system. Our goal was to evaluate and to compare the physical compatibility of three commercial propofol lipid emulsions of different manufacturers, mixing them with the most commonly used crystalloids in intensive care units.

Methods: Simulated Y-site administration was accomplished by mixing the 2% MCT/LCT propofol emulsions with the commonly used crystalloids in the intensive care unit in a 1:1 ratio in a polypropylene syringe. The aliquot samples were evaluated immediately and at 15, 30, 60 and 120 min after preparation by visual observation, pH and droplet size measurement.

Results: There was no emulsion breakdown or any visible change during the study period. Mixing the propofols with crystalloids, 10% magnesium sulphate or 10% potassium chloride there was no significant change in the droplet size compared with the original propofol emulsions. A slight alteration in droplet size was noticed in a few of the propofol samples, when magnesium, potassium or both were the secondary additives to the crystalloids, but this is not considered clinically relevant.

Conclusion: The physical properties of emulsions are determined by component, therefore the compatibility data in literature has to be evaluated prudently. All three commercially available MCT/LCT propofol emulsions are considered physically compatible with the tested crystalloids.