Stability of folic acid in 25% dextrose, 3.5% amino acids, and multivitamin solution

The chemical stability of folic acid in 25% dextrose, 3.5% amino acids, and multivitamin solution was investigated. Solutions of 0.25, 0.5, 0.75, and 1.0 mg/liter of folic acid admixed in the study solution were prepared. Solutions were stored in light-room temperature, light-refrigeration, dark-room temperature, or dark-refrigeration. Samples were drawn to determine folic acid concentration and again at 4, 8, 12, 18, 24, 36, and 48 hr after admixture. Folic acid concentration was determined by competitive binding radioassay, and results are expressed as percent of initial folic acid concentration. Folic acid was stable for 48 hr with each tested concentration and stability was found to be independent of temperature or light storage effects. Folic acid admixed in the study solution is chemically stable for up to 48 hr after initial admixture under normal total parenteral nutrition storage conditions.