Particle size in parenteral fat emulsions, what are the true limitations?

Abstract

Intravenously administered fat droplets exceeding 5 μm in diameter are believed to cause adverse reactions, in particular emboli in the lungs. We investigated the fat particle size and particle size distribution of commercially available parenteral fat emulsions. Both laser diffraction and light obscuration were used as a detection technique. With the light obscuration technique a significant number of particles > 5 μm in diameter was detected in all investigated emulsions. The investigated emulsions have been in use for several years, without reports of important adverse reactions in this respect. Therefore, it is concluded that the requirements concerning the particle size limitations in fat emulsions should be reconsidered.