Whether it’s a can of paint tucked away in the basement, jugs of pesticides waiting in a shed for next season, or a tank of solvent in a chemical plant, knowing the product will still perform as expected is critical to your company’s reputation. Stability testing holds the key.
In follow-up to our previous blog post about which types of analytical tests are important during product development, we’re digging more specifically into stability testing, an area of analytical testing we are passionate about. Stability testing is important during both product development and throughout the product’s time in-market. Stability testing is used to:
- Understand a product’s shelf life
- Determine optimum packaging and storage conditions
- Meet regulatory compliance
- Assess safety and efficacy over time
- Understand how the product may degrade over time
- Determine if an alternate ingredient or technical source will impact shelf life
- Evaluate product quality over time and when there are changes in the manufacturing process
Stability testing can take two paths – accelerated storage stability and ambient-temperature storage stability. Accelerated storage testing condenses the timeframe of the testing by altering the temperature at which it is stored. For example, storing at 54° Celsius (C) and testing over the course of two weeks simulates two years of storage at ambient, or room, temperature.
Companies conduct accelerated storage testing for products they expect to have a long shelf life. Most companies don’t have the luxury of time to test a product over the course of two years; they’re pressed to convert their research and development (R&D) investments into product sales. Regulatory bodies like the Environmental Protection Agency (EPA) recognize accelerated storage stability studies as meeting their data requirements, enabling companies to remain in compliance with regulations. On the other hand, ambient-temperature storage tests the product at room temperature over the desired timeframe.
Parameters and Set Up
When starting a stability study, our team works with customers to align their needs to testing parameters. Some customers have already developed stability protocols, whereas others look to us for guidance. In addition, some customers will prepare the test batches, or samples, while others provide us with their manufacturing or batch sheet and ingredients for us to prepare in our lab.
“I’m working with one customer who is looking at alternate sources of technical. They’ve provided me with one control sample with the technical they’ve been using, and they’ve also prepared samples with three other technical sources and sent to me with their testing regimen,” said Victoria Maskule, one of our analytical chemists.
Testing regimens should outline the length of time, heat/cold variables and analytical tests, such as those discussed in our previous blog post. “The most common testing duration we receive is two weeks at 54° C, which simulates two years. We can also customize the temperature and duration based on what the product can handle. For example, one product we’re working with doesn’t handle temperatures over 40° C, so we’re testing it at 35°, 40° and 54° C. And we need to test it longer to simulate the two years, so at 40° C we’d need to test it for 16 weeks,” Maskule explained.
“Stability testing is very time intensive, and many companies are too busy in their labs to do the needed stability testing or invest in the specialized equipment. Some companies also want an outside lab to validate what they’re seeing in their labs. We partner with both types of companies and are very flexible to address the needs they have, or help them uncover what their needs are,” Maskule elaborated.
Equipment and Analysis
Accelerated storage studies need to ensure the temperature and humidity levels remain constant during the course of the study. We have three ovens, two refrigerators and a freezer onsite to enable us achieve that consistency. They also allow us to test a product’s response to a range of temperatures to see how much heat it can withstand and how it responds to freeze/thaw cycles.
When conducting stability tests, we use many of the same analytical tests and equipment as when we’re developing a formulation. What may differ are the attributes being evaluated and how they respond to changes in time and temperature. Some common analytical equipment we use to quantitatively evaluate chemical and physical changes throughout the study include:
- High-Performance Liquid Chromatography (HPLC): Tests the purity and degradation of the product to ensure it remains consistent for the desired timeframe.
- Fluorescence Microscope: Enables us to see if there is any crystal growth, which can’t be seen with the naked eye.
- Particle Size Analyzer, such as Beckman Coulter: Checks that particle size doesn’t change over time or at different temperatures, which would impact flowability and coverage of the product.
- Brookfield Viscometer: Tests viscosity to ensure the product continues to flow and mix as desired.
“When I receive the initial samples from a customer, I’ll test each one to establish the benchmarks for each type of test. Then I put them in stability. At each designated timeframe, I pull them out and do the same testing over again. The quantitative tests are important because they serve as a quick red flag if something decreases. For example, if the assay or amount of active ingredient present decreases, that indicates there’s an issue. We report our findings at each interval, and sometimes if there are big issues, the customer will stop the testing so they can do further work on the formulation. Or they can employ our services to help correct the formulation,” Maskule explained.
Beyond initially understanding the shelf life and stability of new products, stability testing is important for the duration of a product’s lifespan, particularly as ingredient sources may change and environmental conditions may fluctuate. Our team and facilities are equipped to manage the varied needs of your stability study programs.
Connect with CJB Applied Technologies for your testing needs
For companies with a deep R&D pipeline or limited staffing expertise, completing the necessary stability and analytical testing can be a challenge. Our team is backed by decades of analytical, stability and formulation experience to help companies fill their testing capacity gaps. In addition, our pilot plant team supports your scale-up needs through commercialization. We use our pilot plants to ensure your formulation is tested at sufficient volumes to mimic commercial production so there are no issues when you transition to full-scale production. We also use our pilot plants for custom or small-volume batches. And if you are experiencing production capacity constraints, our team can seamlessly transition your product to our sister company CJB Industries for commercial production.
Are you creating synthetic or biological products and need analytical testing support, such as stability testing, clean out validation, retain evaluation and more? Contact us today. You can tap into any of our services independently of the others – product development, analytical testing, method development, scale up and commercialization needs.
Also, be sure to check back soon or follow us on LinkedIn as we wrap up this blog series with insights into developing analytical methods. And check out other blog posts in this series:
