Effect of the intravenous lipid emulsions on the availability of calcium when using organic phosphate in TPN admixtures.

Purpose: The addition of high amounts of calcium remains a pharmaceutical concern due to its precipitation with phosphate in total parenteral nutrient (TPN) admixtures, compromising also the stability of the lipid emulsion.

Materials And Methods: Calcium-phosphate solubility was compared when using binary PN solutions versus all-in-one TPN (admixtures with lipid emulsions) in three formulas using organic calcium gluconate and glucose-1-phosphate.

Results: It was found that variation of Ca-P solubility exists between formulation with or without lipid emulsions. Concentrations of Ca decreased after filtrations of all admixtures (from 5% to 30%) and it was more significant in binary solutions. Precipitation has been observed by microscopy at high concentrations of both organic Ca-P after critical conditions of storage (24 h at 37 degrees C plus one day at ambient temperature) for admixtures containing 1% amino acids and 8% glucose with or without lipids compared to admixtures containing 2% or 3.5% amino acids and 14% glucose.

Conclusions: These data demonstrated that availability of Ca using organic glucose-1-phosphate increased when lipids were present in TPN admixtures, without alteration of the lipid emulsion. Thus, high amounts of Ca (up to 30 mmol/l) and phosphates (up to 40 mmol/l) might be provided safely in parenteral nutrition admixtures.