STUDY PROTOCOL - STABILITY OF MORPHINE INJECTED WITHOUT PRESERVATIVE,DELIVERED WITH A DISPOSABLE INFUSION DEVICE

Background and objective: Morphine hydrochloride, a major analgesic dr ug, is being increasingly administered using portable disposable infus ion devices. The objective of this study was to investigate the stabil ity of morphine in such a system at two concentrations (2.50 and 5.00 mg/ml) over a 30-day period. Method: High-performance liquid chromatog raphy of stored morphine solutions. Results: The best stability was ob served with disposable infusion devices filled with a morphine solutio n containing sodium metabisulphite as a preservative. No breakdown pro ducts were detected after I month of storage at room temperature, in l ight or darkness. On the other hand, 2.50 and 5.00 mg/ml morphine solu tions without sodium metabisulphite, stored in the infusion device led to the formation of 0.205% and 0.235% of pseudomorphine, respectively , after 6 days of storage in the light, and 1.50% and 0.94% after 30 d ays storage. Conclusion: Morphine hydrochloride solutions stored in di sposable infusion devices degraded very slowly, particularly when pres erved with sodium metabisulphite. The solutions are stable over 5 days , the maximum period of storage normally required when using disposabl e infusers.