Background In clinical practise electrolyte enrichment of the parenteral nutrition admixtures is a typical request, especially on the neonatal/paediatric wards. The supplementation of parenteral nutrition with high concentrations of electrolytes is an ongoing problem since the stability of lipid emulsions in nutrition admixtures is reduced by bivalent cations.

Purpose To examine the stability of 48 different paediatric admixtures designed for home parenteral nutrition. The admixtures investigated were characterised by high concentrations of electrolytes (20–61 mmol/l K⁺, 9–21 mmol/l Ca²⁺, 6–20 mmol/l Mg²⁺).

Materials and Methods Parenteral pre-admixtures were prepared in two-chamber ethyl-vinyl-acetate bags, where a lipid emulsion was separated from the other components. Parenteral pre-admixtures (in two chambers) were stored up to 21 days at +4ºC. Vitamin preparations were added only after combining the contents of two chambers of the bag.

Visual observations, globule size measurement (optical microscopy, laser diffraction (LD) and photon correlation spectroscopy (PCS)), zeta potential, pH analysis and surface measurements were performed in complete admixtures at t = 0 and after 24 h at room temperature.

Results In microscopic observation all admixtures were characterised by size of oily droplets not larger than 1 µm, which was confirmed using LD and PSC methods (Z-average was 260–310 nm). Oily droplet size did not change during the time of storage. Only in two admixtures were single particles up to 8–10 µm observed, so these admixtures were classified as unstable. The pH values of parenteral admixtures were in the range 5.6–6.7 and zeta potential was −36 to −47 mV and did not change during storage.

Conclusions Of the 48 admixtures investigated only two were problematic and the others may be stored for at least 21 days at 4°C. The completed admixtures demonstrated stability for at least 24 h at room temperature. It was possible to obtain stable admixtures despite the high concentrations of electrolytes.

No conflict of interest.