Increased use of intravenous in-line filtration for all-in-one admixtures has been one of several recent stimuli to developing methods for assessing the stability of parenteral nutrition regimens. Admixture formulations previously deemed to be ‘stable' have caused filter blockage and this requires urgent reconsideration of the definitions of physical emulsion stability. The new technique of acoustic attenuation spectroscopy has been evaluated as another means of assessing physical stability of emulsions, and some of the newer techniques have been further applied to provide additional insight into the effects of light and oxygen. There has also been additional work on trace element contamination and changes in trace element concentrations on storage. Overall this review period has been one of evolution rather than revolution.