Stability of dobutamine in continuous ambulatory delivery devices

Continuous infusion of dobutamine plays an important role in the management of patients with end-stage heart failure. Home infusion of dobutamine using a continuous ambulatory delivery device (CADD) facilitates the management of patients in their home, avoiding complications associated with long-term hospitalization. However, the stability of dobutamine in CADD is currently unknown. Therefore, this study investigated the physicochemical stability of dobutamine in CADDs at three different temperatures over various time points.

Six CADDs (three containing dobutamine 10 mg/mL in 0.9% sodium chloride and three containing dobutamine 10 mg/mL in 5% glucose) were prepared and stored at 4°C for 7 days, followed by 12 hours at 35°C and then for another 12 hours at 25°C. An aliquot (n = 3) was withdrawn aseptically at 0, 24, 48, 72, 96, 120, 144 and 168 hours when stored at 4°C, and at 0, 6 and 12 hours when stored at the other two temperatures. Each sample was analysed for dobutamine concentration using a stability-indicating high-performance liquid chromatography. All the samples were also evaluated for change in pH, colour and for particle content.

No evidence of particle formation, colour or pH change was observed throughout the study period. Dobutamine, when admixed with 0.9% sodium chloride or 5% glucose, was found to be chemically stable for at least 168 hours at 4°C and for another 12 hours at 35°C and for another 12 hours at 25°C.

Our findings will allow health professionals to provide a weekly supply of dobutamine-containing CADDs to patients for home infusions. Continuous infusion over a 24-hour period using one CADD per day will also decrease the number of exchanges required and thus reduce the risk of catheter-related bloodstream infections.