Stability of meropenem in normal saline solution after storage at room temperature

Area of Science:

• Pharmacology and Pharmaceutical Sciences
• Infectious Diseases
• Clinical Pharmacy

Background:

• Meropenem's bactericidal activity relies on maintaining serum and tissue concentrations above the Minimum Inhibitory Concentration (MIC) for pathogens.
• Continuous infusion is an optimal administration method for meropenem to ensure sustained therapeutic levels.
• The stability of reconstituted meropenem solutions is critical for effective continuous infusion, particularly concerning storage temperature.

Purpose of the Study:

• To evaluate the stability of meropenem solutions during 8-hour continuous infusion under tropical environmental conditions.
• To provide crucial data on meropenem stability in warm climates, previously lacking for this administration method.

Main Methods:

• Meropenem (0.5 g) was reconstituted in 100 ml of normal saline.
• Solutions were stored for 8 hours at two temperatures: 20°C (air-conditioned) and 32-37°C (room temperature).
• Meropenem concentrations were measured at intervals (0, 1, 2, 3, 4, 6, 8 hours) using 12 solution lots per condition.

Main Results:

• At 20°C, meropenem concentrations decreased by 1.66%, 3.31%, and 5.80% after 2, 4, and 8 hours, respectively.
• At 32-37°C, meropenem concentrations decreased more rapidly: 3.14%, 5.86%, and 11.85% after 2, 4, and 8 hours, respectively.
• Higher temperatures significantly accelerated the degradation of meropenem in solution.

Conclusions:

• Meropenem administered via 8-hour continuous infusion is not stable at typical tropical room temperatures (32-37°C).
• The observed degradation suggests that continuous infusion of meropenem for 8 hours at room temperature in tropical climates may lead to sub-therapeutic drug levels.
• Refrigerated storage or alternative administration methods should be considered for meropenem in tropical regions to ensure treatment efficacy.