[Stability of the mixture of a new fat emulsion with parenteral nutrition solutions]

The stability of the mixture of various parenteral nutrition (PN) solutions with a new fat emulsion containing 50% soybean oil and 50% medium chain triglycerides (MCT) was tested. Five different mixtures were analyzed under transmission electron microscopy 24 hours after the preparation: 1) 10% fat emulsion (FE); 2) FE + PN solution with 5% glucose; 3) FE + PN solution with 12.5% glucose; 4) FE + PN solution with 25% glucose; 5) FE + pure 50% glucose. The pH of each PN solution, fat emulsion and mixture was determined in order to verify if the stability was dependent on the pH of the surrounding medium. The mixture of lipid emulsion with PN solutions did not cause any coalescence of the liposomes or damage to their membranes. However, the addition of 50% glucose to FE coalesced the liposomes, probably due to a decreased pH of the medium (pH = 3.3). We conclude that mixtures of this specific lipid emulsion with PN solutions containing glucose up to 25% are stable for at least 24 hours, and suitable for clinical use in parenteral nutrition.