Comparison of total nutrient admixture stability using two intravenous fat emulsions, Soyacal and Intralipid 20%.

The safe clinical use and physical stability of a total nutrient admixture (TNA) system containing a soybean oil emulsion (Intralipid) has been reported. A study was conducted to compare the physical stability of four admixtures which were divided into two groups based upon the ratios (1:1:1 and 2:1:1) of amino acids (8.5%), dextrose (70%), and fat emulsion (20%). The fat component in each group contained either a new soy bean fat emulsion, Soyacal, or Intralipid. The quantities of all electrolytes, trace elements and vitamin additives were the same. All solutions were stored at 4 degrees C for 28 days and then held at ambient temperature for 5 days for a total 33-day study period. Each admixture was serially analyzed on days 0, 1, 2, 3, 5, 7, 14, 21, 28, 29, 30, 31, 32, and 33. Examination of gross visual appearance and determinations of pH were performed. Osmolality was measured by means of freezing point depression (Advanced Digimatic Osmometer, Advanced Instruments, Inc., Needham Heights, MA). A Brookhaven particle analyzer was used to measure lipid particle size and particle size distribution. Electron and light microscopy were used to verify maximum particle size and distribution on days 0, 7, 14, 21, 28, and 29. The type of lipid emulsion used did not affect the pH or osmolality of the admixtures. Admixtures prepared with the 2:1:1 ratio had slightly higher pH (0.07) and lower osmolality (350 mOsm/kg). The range of mean diameters for the admixtures prepared with Soyacal and Intralipid were 0.283 to 0.310 micron and 0.314 to 0.351 micron, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)