Article Text
Abstract
Background Parenteral Nutrition (PN) is a technique of Artificial Nutrition used to feed patients who cannot or should not get their nutrition through eating. Preparation is complicated because it involves mixing, with aseptic technique, nutritional substrates with different chemical-physical features (water, glucose, amino acids, electrolytes, trace elements and vitamins) to obtain a sterile nutritional emulsion that must be stable during preparation, storage and administration.
Purpose To check the stability of nutritional formulae for parenteral nutrition.
Material and methods Six nutritional formulae were prepared, three variations for each, using three kinds of lipid emulsion. Also added: long chain triglycerides (LCT) emulsion from soybean oil and middle chain triglycerides (MCT) emulsion from coconut oil; enriched lipid emulsion (LCT + MCT) from soybean, olive, coconut and fish oils; omega-3 emulsion from refined fish oil. Each formula was prepared with different calcium concentrations, which, together with viscosity, is the critical parameter that affects Zeta potential and consequently stability. Analysis was performed using a helium-neon laser granulometer on diluted samples at time 0 and after 24, 48, 72 and 96 h in order to reproduce normal storage conditions and clinical use.
Results The results of the analyses of lipid particles established different stabilities, depending on the different kind of lipids and concentration of calcium: nutritional formulae prepared with LCT + MCT have proved 96 h stability, independently of calcium concentration; nutritional formulae with enriched lipids and/or LCT/MCT and lipids from refined fish oil have been proved stable only if the calcium concentration is less than 9 mEq/litre.
Conclusion The results suggest a 96 h shelf life from preparation for nutritional formulae prepared with LCT + MCT. Stability is maintained only if the calcium concentration is less than 9 mEq/litre in nutritional formulae prepared with enriched lipids or with the addition of LCT + MCT and fish oil.
Reference
SINPE Guidelines for Hospital Artificial Nutrition 2002; RINPE Year 20, S5: Update October 2003
ReferenceNo conflict of interest.