Stability of famotidine 20 and 50 mg/L in total nutrient admixtures

The stability of famotidine in total nutrient admixtures (TNAs) containing dextrose, an intravenous fat emulsion (IVF), and high or low concentrations of amino acids was studied. Famotidine was added to TNA solutions to final concentrations of 20 and 50 mg/L. TNA 1 contained 20% dextrose, IVF 40 g/L, and amino acids 42.5 g/L, and TNA 2 contained 25% dextrose, IVF 25 g/L, and amino acids 21.25 g/L. Control solutions of TNAs 1 and 2 without famotidine were also studied. All solutions were stored at 4 degrees C for 24 hours and then at 20-22 degrees C for 24 hours. The solutions were observed for signs of creaming or coalescence and measured for pH, famotidine concentration, and particle size at 0, 24, and 48 hours. No signs of creaming or coalescence were observed in control or test solutions throughout the study period. Famotidine in TNAs 1 and 2 showed a less than 5% change in concentration over the 48-hour period. Neither time nor amino acid concentration had any significant effect on famotidine concentration. Similarly, there were no significant differences in emulsion particle size between control solutions and TNAs containing famotidine and no significant changes in particle size over time. Famotidine 20 and 50 mg/L is stable in the TNAs tested when stored at 4 degrees C for 24 hours and then at 20-22 degrees C for 24 hours. Famotidine did not appear to disrupt the integrity of the emulsion system.