Do carnitine and extra trace elements change stability of paediatric parenteral nutrition admixtures?

INTRODUCTION: High concentrations of trace elements (TE), in particular zinc and selenium, along with carnitine, are often added to parenteral admixtures in paediatric patients on long-term Parenteral Nutrition (PN). We aim to evaluate whether lipid droplet diameters of these admixtures maintain the recommended range of 0.4-1.0 µm. MATERIALS AND METHODS: Stability studies were carried out on six parenteral admixtures with carnitine, trace elements and electrolytes added in different amounts. Each admixture was formulated with five different lipid emulsions with or without fish oil. Analyses were performed at time 0 (t = 0) and 24, 48, 72, 96 (t = 96) hours after compounding. Droplet diameters were determined by Light Scattering-Reverse Fourier Optics Technique. Samples, stored at 4 °C, were triple tested for a total of 450 analyses. Regression analyses were performed using panel-data techniques. RESULTS: During the 4 days, lipid droplet diameters were in the expected range of 0.4-1.0 µm regardless of trace element and carnitine amounts in all admixtures apart from those containing fish-oil based emulsions and calcium concentrations equal to 4.5 mmol/L. In these latter admixtures, 12% of droplet diameters were larger than 1.0 µm and 2% exceeded 5.0 µm immediately after compounding. CONCLUSION: Carnitine and high concentrations of trace elements do not affect PN admixtures stability and can be safely infused in long-term home-PN paediatric patients and prematures. Only high calcium concentrations in compresence with fish oil based lipid emulsions seem to change PN stability.

Parenteral nutrition admixtures for pediatric patients compounded with highly refined fish oil-based emulsion: assessment of physicochemical stability.

Fish oil-based emulsion is increasingly used in pediatric patients receiving Parenteral Nutrition (PN). However, its unique use in children on long-term PN is nutritionally debatable as some patients are better off with a mixture of long-chain (LCT) or long-chain + medium-chain (LCT + MCT) triglycerides along with Fish Oil (FO). Lipid emulsions are safely infused when particle diameter ranges between 0.4 and 1.0 micron (like chylomicra), according to European guidelines. No data exist on Fish Oil stability when added to other PN components typically present in pediatric formulations such as other lipids or micronutrients. Our goal is to evaluate the stability of a highly refined FO-emulsion in PN admixtures containing LCT or LCT + MCT triglycerides and different calcium content. Stability studies were carried out on six PN admixtures having two levels of calcium concentration compounded with olive oil LCT + FO, LCT + MCT + FO emulsion and pure FO alone, respectively. The analyses were performed immediately at time 0 (t = 0) and 24, 48, 72, 96 (t = 96) hours after compounding. Particle diameters were determined by Light Scattering-Reverse Fourier Optics Technique by means of a Laser Granulometer. Every sample was stored at 4 °C and triple tested. Statistical significance was verified by f-test. In all admixtures, physicochemical stability did not change between t = 0 and t = 96 and particle diameters were in the expected range of 0.4-1.0 micron provided calcium concentration remained below 4.5 mmol/L. When calcium exceeded that level, 12% of particle diameters was larger than 1.0 micron and 2% exceeded 5.0 micron immediately after compounding. In particular, admixtures compounded with olive oil LCT + FO emulsion or FO emulsion alone showed lower particle diameters compared to admixture with olive/soybean LCT alone, probably due to a different steric encumbrance of oleic acid and omega-3 fatty acid. In the PN admixtures tested, containing FO-emulsion alone or in combination with olive LCT or LCT + MCT, the fat emulsion appears to be stable and safe for infusion when calcium concentration is maintained below 4.5 mmol/L. If calcium level exceeds 4.5 mmol/L, as often required in premature patients, it is advisable to infuse FO emulsion alone through a second intravenous line.

Analysis of all-in-one parenteral nutrition admixtures by liquid chromatography and laser diffraction: study of stability.

All-in-one parenteral nutrition admixtures are complex lipid emulsions (oil/water) which require absolute sterility, stability and no precipitates. Particle diameter must be in the range 0.4--1 microm in order to mime the size of chylomicra. Added vitamins must not degrade during infusion time (24 h). In this study, the physicochemical stability of parenteral nutrition admixtures was tested in the course of time at different storage temperatures. Two liquid chromatographic methods, based on solid phase extraction (SPE), were developed for fat-soluble vitamin determination. Stability studies were carried out on three industrial lipid emulsions and on six compounded all-in-one admixtures. They were stored at three different temperatures: 4 degrees C (storage), 25 degrees C (compounding) and 37 degrees C (infusion); then they were analyzed at starting time and at 24, 48 and 72 h after compounding. Particle diameter was determined by means of Laser Particle Sizer Analysette 22, which uses laser diffraction technique (light scattering -- reverse Fourier optics). Fat-soluble vitamins (retinol palmitate and alpha-, delta-, gamma-tocopherol) were determined in admixtures with a branded vitamin compound called Idroplurivit Liofilizzato. Samples were extracted by SPE on C(18) cartridges, then they were separated by reversed-phase liquid chromatography (LC) and detected by ultraviolet detection (retinol palmitate) and electrochemical detection (tocopherols). Laser diffraction analysis pointed out that particle size did not change in the course of time at the tested temperatures. LC analysis showed that vitamins interact each other and degrade after compounding at different times and storage temperatures; only retinol palmitate is stable at 37 degrees C. Retinol palmitate recovery was 98%, coefficient of variation (CV) 5.4%, detection limit 25 microg/l, limit of quantitation 75 microg/l and there were not interfering substances. Tocopherols average recovery was 99%, CV 3.5%, detection limit 15 ng/l and limit of quantitation 50 ng/l. In conclusion, all-in-one parenteral admixtures were proved to be physically stable under analysis conditions, but degradation of retinol palmitate and tocopherols requires admixtures with vitamins to be infused within 24 h after compounding.