Shelf lives of aseptically prepared medicines--stability of netilmicin injection in polypropylene syringes

There is no published information on the stability of netilmicin solutions in prefilled syringes. The purpose of this study was to evaluate the stability of netilmicin in polypropylene syringes and to determine the optimum validated shelf life so that they may be prepared in bulk in appropriately licensed facilities.

The syringes containing netilmicin 10 or 100 mg/ml were stored at 7 °C, room temperature in the light (RTL) and 25 °C/60% relative humidity for up to 300 days.

Netilmicin concentration was determined by reversed phase high performance liquid chromatography (RP-HPLC) of the isoindole derivative formed with o-phthalaldehyde (OPA). The shelf lives were calculated using the maximum rate method applied to the netilmicin analytical data. At 7 °C 10 and 100 mg/ml solutions were stable for 90 days falling to 30 days at 25 °C and 60% RH. At RTL the 10 mg/ml solution was stable for 9 days.