Ergometrine stability in postpartum haemorrhage kits: Does temperature and light matter?

Abstract

Postpartum haemorrhage (PPH) kits containing uterotonics are used on obstetric units for the timely management of PPH. Visible discolouration of ergometrine and ergometrine-oxytocin injections was observed in PPH kits stored in medical refrigerators on the obstetric unit at our hospital. To investigate the stability of ergometrine and ergometrine-oxytocin injections in PPH kits under simulated clinical storage conditions and to determine the potency of ampoules quarantined from PPH kits on our obstetric unit. Ergometrine and ergometrine-oxytocin injection ampoules were stored exposed to and protected from light at 4°C and room temperature (25°C) for up to threemonths, and assayed by high-performance liquid chromatography. Stability was based on the time for the ergometrine or oxytocin concentration to fall to 90% of the original concentration (t90 ). The potency of quarantined discoloured ampoules also was determined. Ergometrine was stable at both temperatures for >6months, when stored protected from light in simulated clinical conditions. When exposed to light, ergometrine was stable for approximately 4days at 25°C and 10days at 4°C. Discoloured ergometrine and ergometrine-oxytocin injection ampoules were found to be <90% of the nominal concentration. Stability of ergometrine in PPH kits is largely unaffected by temperature fluctuations (at 4°C and 25°C) over 6months when protected from light. Ergometrine and ergometrine-oxytocin ampoules should be inspected prior to use and any discoloured ampoules discarded.