Background and importance At the end of 2018 there was a shortage and withdrawal from the market of D-fructose-1,6-diphosphate (Esafosfina), a phosphate source for the extemporaneous preparation of bags for neonatal total parenteral nutrition (TPN). Therefore, a solution of sodium glycerophosphate (Natriumglycerophosphat-Ampulle Fresenius) was imported from abroad. This solution is different because it contains L-malic acid as an excipient. No stability data on Natriumglycerophosphat-Ampulle Fresenius in TPN bags were found in the literature.

Aim and objectives To test the compatibility and stability of Natriumglycerophosphat-Ampulle Fresenius in TPN bags we prepared.

Material and methods Neonatal TPN formulations are customised: therefore, we identified three test formulations, with varying concentrations of phosphate, calcium and magnesium (critical components), with and without lipids. Turbidity and pH controls were planned at appropriate time intervals (0, 24, 48, 72 and 96 hours after preparation) and under different storage conditions (room temperature, refrigerated and at 37°C). These controls were performed either with lipid free or with all in one formulations (all components, including lipids, are mixed in the same bag).

Results In lipid free formulations there was no formation of a precipitate at room temperature or under refrigerated conditions. The absorbance of the solutions at 600 nm (turbidity reading) remained below 0.010, which means no evidence of precipitation. There was precipitate formation under storage condition at 37°C (after 72 hours in test bags No1 and No2 and after 96 hours in bag No 3). The determining factors of the formation of this precipitate are alteration and degradation of the amino acids and the resulting pH reduction. In all in one formulations, we assessed stability with a microscope. Coalescence started in a bag 48 hours after preparation. Solution pH ranged from 5.5 to 6.5.

Conclusion and relevance Sodium glycerophosphate (Natriumglycerophosphat-Ampulle Fresenius) can be mixed with the usual components for neonatal TPN. In the test formulations there was no physical or chemical incompatibility. Lipid free formulations were stable for at least 96 hours. All in one formulations should be infused within 24 hours, especially if the amount of lipids is high.

References and/or acknowledgements No conflict of interest.