Stability of ranitidine hydrochloride and amino acids in parenteral nutrient solutions.

The stability of ranitidine hydrochloride in parenteral nutrient (PN) solutions and the effect of ranitidine hydrochloride on the amino acids in the PN solutions were studied. Six PN solutions (three each with amino acid contents of 2.125 and 4.25%) were prepared. Each PN solution also contained dextrose 25%, electrolytes, trace elements, vitamins, and heparin sodium. Ranitidine hydrochloride injection was added to four of the PN samples. Of the final samples, two contained no ranitidine, two contained ranitidine hydrochloride 50 micrograms/mL, and two contained ranitidine hydrochloride 100 micrograms/mL. Admixtures of ranitidine hydrochloride at the two concentrations in 0.9% sodium chloride injection were also prepared. Samples were observed for color change and tested for pH during storage at room temperature. Concentrations of amino acids were measured after 24 hours in samples without ranitidine and in samples containing ranitidine hydrochloride 100 micrograms/mL. Ranitidine hydrochloride content was determined by high-performance liquid chromatography at 12, 24, and 48 hours. No visual changes or pH changes occurred by 24 hours. All PN solutions became darker by 48 hours. The presence of ranitidine hydrochloride did not substantially affect amino acid concentrations. At 24 hours, at least 90% of the initial ranitidine concentrations remained in all samples. In three of the four PN samples at 48 hours, less than 90% of initial ranitidine concentrations remained. Ranitidine hydrochloride in concentrations of 50 and 100 micrograms/mL in parenteral nutrient solutions containing 4.25 and 2.125% crystalline amino acids is stable for 24 hours at room temperature. Under these conditions, concentrations of the amino acids contained in the PN solutions were not affected by the addition of ranitidine hydrochloride.