Microbial Contamination Test of Ceftriaxone Infusion Solutions

Abstract

Ceftriaxone is an antibiotic belonging to the third generation of cephalosporins. It is commonly prescribed to treat various infectious diseases in hospitalized patients. While ceftriaxone infusion solution is chemically stable for 2–10 days, the expiration date is limited to approximately 24 hours due to a lack of data on microbiological stability beyond this period. Therefore, this study aimed to investigate the microbial contamination of ceftriaxone infusion solutions stored beyond 24 hours to establish an appropriate expiration date. Methods: Ceftriaxone infusion solution was prepared under a laminar airflow environment to achieve final concentrations of 10–20 mg/mL. There were four groups of ceftriaxone solutions. Group 1 comprised 20 samples of a 10 mg/mL ceftriaxone solution stored at room temperature (28–30 ºC). Groups 2 and 3 included 20 samples each of 20 mg/mL ceftriaxone stored at room temperature (28–30 ºC) and under refrigeration (2–8 °C), respectively. Group 4 consisted of 15 samples of 48-hour-old leftover ceftriaxone solutions stored in a refrigerator (2–8 ºC) at hospital wards. Microbial contamination was determined using the direct inoculation method; fluid thioglycolate media was incubated at 30–35 ºC for the detection of aerobic and anaerobic bacteria, while soybean-casein digest media was incubated at 20–25 ºC for the detection of fungi, and both were observed for a period of 14 days. Results: After a 10-day period of preparation and storage, all ceftriaxone test samples in groups 1, 2, and 3 were negative for microbial growth. Similarly, the leftover ceftriaxone solutions in Group 4 exhibited no bacterial contamination. Conclusion: Ceftriaxone infusion solutions 10–20 mg/mL demonstrated biological stability for at least ten days post-preparation. However, considering the limitations of chemical stability, the recommended expiration dates for ceftriaxone solutions are 30 hours when stored at 28-30 ºC, 48 hours when stored at 25 ºC, and up to 10 days when stored at 2-8 ºC.