Particulate evaluation of parenteral nutrition solutions by electronic particle counting and scanning electron microscopy.

The particulate matter contamination of four commercial parenteral nutrition solutions that contained high concentrations of amino acids and dextrose was evaluated. Electron particle counting and scanning electron microscopy (SEM) were used to evaluate the amount of particulate matter over a 24-hour-period. The effect of adding 10 meq calcium and 20 meq phosphate electrolytes on the particulate content of these four solutions was determined also. Both counting methods agreed in the rank order comparison of particulate contamination, in that the Abbott and Travenol solutions contained the fewest particles while the Cutter solutions contained the most. The addition of calcium and phosphate resulted in at least a 50% increase in the mean particle count of all solutions. The SEM analysis showed the mean presence of microscopically large, yet subvisible, particles in the solutions containing phosphate and calcium. All of the solutions followed a previously published relationship between particle number and size. Although all of the solutions contained particulate matter, even the solutions with calcium and phosphate contained fewer particles than allowable by the USP-NF standard.