Stability of milrinone in continuous ambulatory delivery devices

The stability of milrinone in continuous ambulatory delivery devices (CADDs) stored at 4, 25, and 35 °C was evaluated.

Six CADDs (3 devices containing milrinone plus 0.9% sodium chloride injection and 3 devices containing milrinone plus 5% dextrose injection) were prepared. Devices were kept at 4 °C for 168 hours, followed by 24 hours at 25 °C and an additional 24 hours at 35 °C. Samples (n = 3) were withdrawn aseptically at 0, 24, 48, 72, 96, 120, 144, and 168 hours from the CADDs stored at 4 °C and at 0, 6, and 24 hours from the CADDs stored at 25 and 35 °C. The milrinone concentration of each aliquot was analyzed using a stability-indicating high performance liquid chromatographic method within 15-30 minutes of preparation. The samples were also evaluated for changes in pH, changes in color, and particulate content. Six control samples (3 containing 0.9% sodium chloride injection and 3 containing 5% dextrose injection) were prepared and similarly analyzed.

Milrinone admixtures retained more than 99% of their initial concentration for 168 hours at 4 °C and for 24 hours when stored at 25 and 35 °C. No evidence of particle formation, color change, or pH change was observed throughout the study period.

Milrinone 600 μg/mL prepared in either 0.9% sodium chloride injection or 5% dextrose injection in CADDs was stable for 168 hours when stored at 4 °C and for 24 hours when stored at 25 and 35 °C.