Related Experiment Videos
Stability of cefazolin sodium and metronidazole at 8 degrees C for use as an i.v. admixture
T E Rivers1, H A McBride, J M Trang
1Clinical Pharmacy Services, Baptist Medical Center Princeton, Birmingham, Alabama.
Insights
Cefazolin and metronidazole IV admixture remained stable for 72 hours at 8°C. This study confirms the stability of this combination for potential clinical use.
Area of Science:
- Pharmaceutical Sciences
- Clinical Pharmacy
Background:
- Intravenous (IV) admixtures require stability assessments for safe and effective clinical use.
- Cefazolin and metronidazole are commonly used antibiotics that may be co-administered.
Purpose of the Study:
- To evaluate the stability of cefazolin in combination with metronidazole when prepared as an IV admixture.
- To determine the compatibility and shelf-life of this specific drug combination under refrigerated conditions.
Main Methods:
- Cefazolin sodium was reconstituted and added to a metronidazole solution.
- The IV admixture was stored at 8°C and analyzed at various time points up to 72 hours.
- A stability-indicating high-performance liquid chromatographic (HPLC) method was used to quantify cefazolin and metronidazole concentrations.
Main Results:
- Cefazolin concentrations remained within 98.4% to 101.0% of the initial concentration over 72 hours.
- Metronidazole concentrations ranged from 96.9% to 104.9% of the initial concentration throughout the study period.
- Both drugs maintained concentrations within 5% of the initial mean concentration, indicating stability.
Conclusions:
- Cefazolin and metronidazole IV admixture is stable for at least 72 hours when stored at 8°C.
- This finding supports the potential for using this combination as a prepared IV admixture in clinical settings.
Abstract:
The stability of cefazolin 1 g in metronidazole 500 mg/100 mL at 8 degrees C was studied for use as an IV admixture. The commercially available injection of cefazolin sodium 1 g vial was diluted to 5 mL with 0.9% sodium chloride injection and added to metronidazole 500 mg/100 mL. Following dilution of 2 mL to 100 mL with water, 1-mL aliquots were transferred to glass vials, refrigerated at 8 degrees, and assayed for cefazolin and metronidazole concentration at 0, 1, 2, 4, 8, 12, 24, 36, 48, and 72 hours after preparation. The concentration of cefazolin and metronidazole was determined by a stability-indicating high-performance liquid chromatographic method. The range of concentration was determined to be within 5% of the 0-hour mean concentration. Over the 72-hour period, the mean concentration of cefazolin at all assay times was within 98.4 to 101.0% of the initial concentration. The mean concentration of metronidazole at each assay time was 96.9 to 104.9% of the initial concentration. Cefazolin sodium 10 mg/mL and metronidazole 5 mg/mL, prepared by adding reconstituted cefazolin to a glass bottle of metronidazole ready-to-use solution, were stable for 72 hours when stored at 8 degrees C.