Stability of sterile aqueous epinephrine injections submitted by U.S. hospitals.

The stability of sterile aqueous epinephrine injections stored in hospital pharmacies across the United States was studied. Through a voluntary drug stability program, FDA selected 254 samples of epinephrine injection submitted by hospital pharmacies. The samples were analyzed for strength, identification, d-isomer content, related impurities, pH, total acidity, and physical condition. Of the 254 samples tested, 23 samples did not meet USP requirements for epinephrine strength. Four of these samples were still within their expiration dates and seven had no expiration dates, indicating they were manufactured before 1975. An additional 19 samples did not meet USP requirements for total acidity. Some samples were found to be racemic; it appears that the racemic mixture originates from using d,l-epinephrine as the starting material rather than from racemization during shelf-life. Epinephrine injections obtained from hospital pharmacies appear to be stable within their expiration dates.