Solubility of calcium gluconate and sodium glycerophosphate in infant parenteral nutrition solutions

Precipitation of calcium and phosphate in parenteral nutrition (PN) solutions remains a significant problem in patients who need high amounts of calcium and phosphorus especially infant patients. The aim of this study were to investigate the effects of concentrations of amino acids, calcium gluconate, sodium glycerophosphate (NaGP), and storage conditions on solubility of calcium gluconate and NaGP in infant PN solutions. The tested PN solution consisted of 10% dextrose, 2.025 mM/L of magnesium, 51.3 mM/L of sodium chloride, 1.5, 2, and 2.5% amino acid, 0-100 mM/L of calcium and 0-150 mM/L of phosphate. Visual inspection, pH measurement, turbidity test and microscopic particle count test were examined. Each admixture was tested according to 4 following storage conditions; room temperature for 30 minutes, room temperature for 1 day, 4 ºC for 1 day and 4 ºC for 7 days. Samples containing 2.5% of amino acid showed no precipitation at all concentrations of calcium gluconate and NaGP used in this study. On the other hand, samples containing 1.5% and 2% of amino acid showed precipitation in the PN solutions at concentrations of calcium gluconate and NaGP higher than those concentrations used in clinical practice. All results from solubility tests were applied to construct solubility data of calcium gluconate and NaGP. Solubility data were applied by infant PN solution orders during July to December in 2016. Solubility data from this study can be used for prescription and preparation of infant PN solutions.