Fat emulsions for parenteral nutrition. IV. Lipofundin MCT/LCT regimens for total parenteral nutrition (TPN) with high electrolyte load

The stability of TPN regimens with high electrolyte load based on the emulsions Lipofundin MCT/LCT and Intralipid was investigated. The regimens were of identical composition containing 66.7 mmol/1 monovalent ions and 6.7 mmol/1 divalent ions (3.4 mmol Ca2+, 3.3 mmol other divalent ions such as Mg2+). Stability was monitored by microscopy, Coulter counter, photon correlation spectroscopy (PCS) and laser diffractometry. Zeta potential measurements were performed by laser Doppler anemometry (LDA). The Lipofundin regimen was regarded as being stable for 7 days of storage, the Intralipid regimen for at least 2 days but not 7 days. The storage time was limited due to visible heavy creaming and the increased numbers of particles > 4 μm. Microscopic, Coulter counter and PCS two-time-window analysis proved suitable for monitoring the stability. Analysis of the top phase of the regimens proved to be distinctly more sensitive than that of the homogenous mixture of the regimens after shaking. The instabilities observed were mainly attributed to the reduction of the zeta potential to the range of maximum flocculation.