STABILITY OF AZTREONAM IN A PORTABLE PUMP RESERVOIR USED FOR HOME INTRAVENOUS ANTIBIOTIC-TREATMENT (HIVAT)

The stability of the monocyclic beta-lactam antibiotic aztreonam in po rtable pump reservoirs was studied during storage at temperatures of - 20 degrees C and +5 degrees C and during drug delivery at 37 degrees C . Three 100-ml drug reservoirs and three glass containers containing 6 0 mg/ml aztreonam were stored at -20 degrees C and 2-ml samples were a nalysed in the freshly prepared solution and after thawing at days 7, 21, 28, 70 and after 6 months of storage. A separate triplicate batch of 100-ml prefilled drug reservoirs and glass containers containing a similar aztreonam concentration (60 mg/ml) were refrigerated and teste d immediately after preparation and daily for 8 days and alter 70 days . Solutions of aztreonam in duplicate freshly prepared reservoirs were tested for stability when the solution was pumped at 37 degrees C ove r a 24-h period. All solutions were inspected for visual changes and t ested for pH. Drug concentration was analysed by high-performance liqu id chromatography. No colour changes or pH differences were observed i n any of the solutions in the reservoirs or containers. No statistical ly significant decrease in aztreonam concentration could be detected a fter 6 months of storage dt -20 degrees C. Aztreonam was stable at 5 d egrees C for at least 8 days. A 24-h pumping period at 37 degrees C sh owed a 3.6% decrease in aztreonam concentration. Aztreonam at a concen tration of 60 mg/ml in a pump reservoir is sufficiently stable to be u sed in home intravenous antibiotic treatment programmes.