Emulsion stability in total nutrient admixtures containing a pediatric amino acid formulation

Emulsion stability of total nutrient admixtures containing TrophAmine amino acid injection admixed with Intralipid, Nutrilipid, and Liposyn II was studied. High and low electrolyte concentrations were added to each total nutrient admixture before storage at 4 degrees C for 48 hours then at 20-22 degrees C for 24 hours. Stability studies were also performed on total nutrient admixtures containing higher concentrations of fat emulsion and total nutrient admixtures with added cysteine hydrochloride and carnitine. High electrolyte concentrations only were added to these total nutrient admixtures before being stored refrigerated for 24 hours then at room temperature for 24 hours. Visual assessment, pH determination, and particle size analysis were performed immediately after compounding and after refrigerated and room temperature storage. Particle size was assessed by measuring the mean diameter of the fat emulsion and the percent of oil volume in particles greater than 5 microns. Repeated-measures analyses of variance were used to determine significance of type or concentration of fat emulsion, electrolyte concentrations, or time on mean diameter or percent particles greater than 5 microns. There were minimal changes in pH values over time. Creaming was observed in all total nutrient admixtures at all sampling times except time zero. This was reversible upon agitation. Results of particle size analysis over time indicated little change in mean diameter or percent particles greater than 5 microns. These minimal changes did not seem to be clinically significant. It is concluded that total nutrient admixtures prepared with this pediatric amino acid formulation are stable when prepared and stored as reported.