Calcium Chloride and Calcium Gluconate in Neonatal Parenteral Nutrition Solutions with Added Cysteine: Compatibility...

Parenteral nutrition (PN) solutions containing calcium gluconate (CaGlu) and cysteine have elevated particle counts when analyzed using laser light obscuration (LO) as recommended by the United States Pharmacopeia (USP). There are no compatibility studies for solutions compounded with cysteine and containing calcium chloride (CaCl₂ ) using LO. The purpose of this study was to conduct compatibility testing for neonatal PN solutions containing CaCl₂ and CaGlu with cysteine.

Solutions of amino acids (2.5%), containing either CaCl₂ or CaGlu plus potassium phosphate, were compounded with 50 and 100 mg/dL cysteine. Solutions were analyzed for particle counts using LO. Maximum concentrations tested were 20 mmol/L calcium and 15 mmol/L phosphate. Three solutions containing CaCl₂ (144 total solutions) and 2 containing CaGlu (96 total solutions) and the same concentration of additives were compounded. If the average particle count of replicates exceeded USP guidelines, the solution was incompatible.

All solutions containing CaGlu had particle counts that exceeded USP guidelines for particle counts ≥10 μm (range, 86-580 particles/mL). For CaCl₂ , 90 of 144 solutions were compatible (range of particle counts for all solutions, 3-121 particles/mL). Maximum compatible concentrations of CaCl₂ and potassium phosphate were 15 mmol/L and 12.5 mmol/L, respectively, for solutions containing both 50 and 100 mg/dL cysteine.

This study found that neonatal PN solutions containing CaGlu with added cysteine have significantly higher particle counts, exceeding USP guidelines for compatibility, than those containing CaCl₂ .