Stability and Compatibility of Alfentanil Hydrochloride and Morphine Sulfate in Polypropylene Syringes

Abstract

Aim: To establish the chemical stability and physical compatibility of alfentanil hydrochloride and morphine sulfate in polypropylene syringes for patient controlled analgesia at the Royal Adelaide Hospital.Method: A stability indicating high pressure liquid chromatography (HPLC) method was developed and validated. Concentrations of alfentanil hydrochloride and morphine sulfate stored in polypropylene syringes were measured over a sixmonth period. Sample syringes were stored under refrigeration (2‐8°C) and at room temperature (22±1°C). Visual inspection for macro particulate matter was undertaken using an Allen viewer. Stability was defined as maintaining at least 90% of the day zero concentration. Quality control standards were assayed on each study day to determine intra‐ and inter‐day precision and accuracy.Results: Morphine sulfate content remained at 99% of initial concentration after 182 days at both storage conditions. Alfentanil hydrochloride content remained at 100% of initial concentration after 182 days at both storage conditions. No particulate matter was visible in sample syringes throughout the study period.Conclusion: Alfentanil hydrochloride and morphine sulfate in polypropylene syringes are chemically stable and physically compatible for 180 days in the concentrations studied, when protected from light and stored either under refrigeration (2‐8°C) or room temperature (22±1°C). An expiry date of six months can be applied, facilitating efficient manufacturing and clinical evaluation in the management of acute pain.