Content continues after advertisement

Stability of Ceftazidime in Varying Storage Temperatures

Jason Pieper, DVM, MS, DACVD, Iowa State University

Sign in to Print/View PDF

In the literature

Hoff SE, Berger DJ, Viall AK, Schrunk D, Noxon JO. Chemical and microbiological stability of diluted ceftazidime in three different solutions under three storage temperatures over a 28 day period. Vet Dermatol. 2021;32(5):456-e124.


FROM THE PAGE...

Because otitis externa can be difficult to treat, noncommercial products with minimal supporting evidence, particularly compounded ear medications (made either in compounding pharmacies or the veterinary clinic), are often used. Stability and efficacy of these products can be influenced by several factors (eg, pH, storage temperature). 

This study examined ceftazidime compounded into solutions with 3 base diluents (ie, 0.9% sodium chloride, tris-EDTA, 0.02% phytosphingosine hydrochloride) and stored at 3 temperatures (ie, 77°F [25°C], 39.2°F [4°C], −4°F [−20°C]). Solutions were evaluated against a standard Pseudomonas aeruginosa strain over 28 days for changes in pH, drug concentration, and antimicrobial activity. 

All drug concentrations decreased over time; decrease was more significant when solutions were stored at room temperature compared with being refrigerated or frozen. Drug concentration of the tris-EDTA solution significantly decreased as early as within 7 days, likely due to the higher pH of tris-EDTA compared with other diluents. 

Antimicrobial activity of each solution was affected by time and temperature. Stability was best achieved with the 0.9% sodium chloride solution when refrigerated or frozen. 

This study illustrates the importance of evidence-based medicine in establishing the efficacy of compounded ear medications. For example, ceftazidime diluted into tris-EDTA and stored at room temperature would become unstable within several days, resulting in ineffective treatment.

...TO YOUR PATIENTS

Key pearls to put into practice:

1

Compounding ear medications for clinical use is possible but should only be done with supporting medical evidence.

 

2

Storage temperature and pH can significantly affect the stability of ceftazidime and whether it is active within a solution.

 

3

Compounded drugs have a limited shelf life. Research showing the maximal shelf life for each compounded mixture is important.

Suggested Reading & Author Information

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Clinician's Brief may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

Podcasts

Clinician's Brief:
The Podcast
Listen as host Alyssa Watson, DVM, talks with the authors of your favorite Clinician’s Brief articles. Dig deeper and explore the conversations behind the content here.
Clinician's Brief provides relevant diagnostic and treatment information for small animal practitioners. It has been ranked the #1 most essential publication by small animal veterinarians for 9 years.*

*2007-2017 PERQ and Essential Media Studies

© Educational Concepts, L.L.C. dba Brief Media ™ All Rights Reserved. Terms & Conditions | DMCA Copyright | Privacy Policy | Acceptable Use Policy