FACTORS INFLUENCING THE STABILITY OF RANITIDINE IN TPN MIXTURES

The stability of ranitidine in TPN mixtures has been widely studied wi th varying results. The evidence suggests that ranitidine is unstable and should be added within 24 h of administration, although other repo rts indicate ranitidine is stable for at least 14 days. The causes of ranitidine degradation in TPN mixtures were therefore studied in mixtu res without fat emulsion using a stability-indicating HPLC method. The results indicated that the stability of ranitidine at 5 degrees C dep ended on the commercial source of amino acid, additives and type of ba g used. The principle mechanism of degradation was identified as oxida tion. Ranitidine was more stable in EVA bags in the absence of the tra ce element additive, which appeared to accelerate ranitidine oxidation . Ranitidine was most stable in mixtures compounded in multi-layered b ags. The results suggest TPN mixtures with ranitidine in multi-layered bags could be assigned shelf lives of at least 14 days at 5 degrees C , depending on the amino acid infusion used in the regimen.