Stability of Meropenem in Normal Saline at 39 degrees Celsius and at different concentrations achieved in a clinical setting

Abstract

Objective: This study was conducted to measure the in-vitro stability of Meropenem at the commonly used concentrations required for infusion in the wards with normal saline as the reconstitute. Methods: We performed the in-vitro study with Meropenem vials taken from the same manufacturer. The concentrations of Meropenem after reconstitution using    normal saline were analysed at six time-points over eight hours; temperature being maintained at 39±2ºC using an  incubator, simulating the indoor ward temperatures achieved in a tropical country. Results: Within the initial three hours, more than 10% degradation was observed for 50 and 100 mg/ml of Meropenem trihydrate. Whereas the 20 mg/ml could be administered up to three hours with an acceptable limit of degradation. At the end of eight hours, there was 39.4%,30% and 23% degradation             of the 100,50 and 20 mg/ml             concentrations respectively. Conclusion: The degradation of 50 mg/ml and 100 mg/ml of Meropenem trihydrate is within acceptable limits up to one hour. but lower concentrations     of 20 mg/ml may be administered up to 3 hours after         reconstitution in normal saline when stored at 39±2℃. It would be possible to administer prolonged/continuous infusion of Meropenem at higher concentrations but would require     repeated reconstitution with normal saline. This would ensure that the degradation of meropenem experienced would remain within the acceptable limits throughout the interdosingperiod.