STABILITY OF FAMOTIDINE IN POLYPROPYLENE SYRINGES USING A STABILITY-INDICATING HPLC ASSAY

Famotidine syringes (2 mg/mL) were prepared under sterile conditions in accordance with United States Pharmacopeia (USP). To test the stability, syringes were kept for 30 d under three different temperature conditions: room temperature (22-25 degrees C), refrigerated (2-6 degrees C), and frozen (-20 degrees C). Three samples from each temperature were withdrawn and were assessed for stability on days 0, 7, 15, 22, and 30 as per the USP guidelines. Physical stability was assessed by visual examination and pH values. The assay of famotidine was examined by a stability-indicating HPLC method and a significant loss of stability was defined as 10% or greater decrease in famotidine content over time. Physical stability results illustrated that no precipitation, cloudiness, or color change was observed in famotidine syringes at all the temperatures studied. Results from the assay content by HPLC showed that famotidine injections retain greater than 90% of the initial concentrations for 30 d when stored at room temperature and frozen; and 22 d when refrigerated. Thus, we can conclude that when stored at room temperature or frozen, diluted famotidine injections (2 mg/mL in sterile water) in 12mL polypropylene syringes are stable for at least 30 d and for 22 d when refrigerated.