Physical Stability of Medium-Chain Triglyceride/Long-Chain Triglyceride Emulsion Injections From 5 Manufacturers in High-Concentration Electrolyte-Based Total Nutrient Admixtures

BACKGROUND Lipid emulsion injections for parenteral nutrition are an important source of energy and essential fatty acids. Yet stability and compounding challenges remain. We compared the physicochemical stability of 5 commercial medium-chain triglyceride/long-chain triglyceride (MCT/LCT)-based lipid emulsions compounded in total nutrient admixtures (TNAs). METHODS Stability of the MCT/LCT-based TNAs was assessed when compounded with high concentrations of electrolytes. We measured mean droplet diameter (MDD), percentage of fat residing in globules ≥5 μm (PFAT5), pH, and osmolality immediately after compounding (time 0) and 6, 12, 18, 24, 36, 48, 60, and 72 hours later. Repeated-measures analyses of variance were used to evaluate changes in stability over time, and post hoc tests were used to assess group differences. RESULTS Over 72 hours, MDD of TNAs ranged from 0.206 to 0.713 μm, PFAT5 from 0.58% × 10-3 to 43.18% × 10-3 , pH from 5.769 to 5.879, and osmolality from 1304 to 1357 mOsm/kg. MDDs and PFAT5s showed a tendency to increase gradually over the first 24 hours and then decrease or remained stable after that. We identified some significant differences in MDDs and PFAT5s among the 5 MCT/LCT-based TNAs, although all met the United States Pharmacopeia standards. CONCLUSIONS The stability of some commercial MCT/LCT-based TNAs under high concentrations of electrolytes exhibits differences over the 72 hours after compounding. Clinicians should pay attention, therefore, to possible performance differences of injectable lipid emulsions produced by different manufacturers when compounded in TNAs under high electrolyte concentrations.