We are often asked: “What is required for stability testing for CBD products?” It’s a tricky question because there are lots factors that go into demonstrating shelf stability. These include the type of product (food, cosmetic, ingredient), the region where it will be sold and its composition. In this blog we will break down what goes into designing a stability program.
Stability studies are used to support shelf stability of a product. Shelf stability can be labeled as an expiration date, a use by date or a best before date, collectively referred to as the date label. The date label required depends on the product type and region. In the preamble to the 2007 Federal Register notice in which the final cGMP rule for dietary supplements was published, the Food and Drug Administration (FDA) explicitly states “…the final rule does not require that you establish an expiration date…”. However, they go on to state that if you do label your supplement with an expiration date your program should follow the drug requirements more than the food requirements for shelf life labeling.
Although in the US there are no date label requirements for dietary supplements or dietary ingredients, it can be considered good practice and will likely be required by retailers. Best before or use by dates are required for food products sold in the UK and EU. The status of cannabinoids as a novel food adds an additional level of complexity. The guidance for the preparation of a novel food application requires data to support the stability of the novel food ingredient (ex. CBD isolate or distillate) over the course of the shelf life at the relevant storage conditions. The guidance also asks for data to support the novel food in various food matrices.
Cosmetics are required to have data to support shelf stability in the EU and UK. These requirements state that you must report “the stability of the cosmetics product under reasonably foreseeable storage conditions”. If the shelf life is greater than 30 months, no expiration labeling is required but the use-by period after opening must be indicated on the label. In the US there are no requirements for cosmetics to have specific shelf lives or expiration dates on their labels, however, manufacturers are responsible for making sure their products are safe. FDA considers determining a product’s shelf life to be a part of the manufacturer’s responsibility.
There are a number of ways to demonstrate stability. These include the analysis of retain samples, accelerated studies or well controlled studies that follow the ICH guidance6.
Retain samples are products that are kept in appropriate storage conditions and tested at a later date. This can be useful to quickly generate supportive data. Retain samples can be tested and the data generated compared to results from when the product was first manufactured to evaluate for change over the time period. This approach can be further bolstered with data for a variety of lots of varying age. As with any study, it is critical that the results are accurate at both the initial test and the aged timepoint to ensure that the assessment of stability is accurate.
Accelerated studies can be used to predict stability. The pharmaceutical industry uses six months of accelerated stability at 40˚C/75% RH (relative humidity) to correlate to 24 months of real time stability. Real time stability is defined as stability at or close to the storage conditions.
The gold standard in stability testing is following the ICH guidelines. Real time and accelerated conditions are detailed with different conditions specified for real time stability for various regions around the world. The most common real time condition is Zone II or 25˚C/60% RH followed by Zone IVb or 30˚C/75% RH, required for tropical climates.
Once the approach is decided, the product needs to be evaluated for what parameters should be analyzed on stability. The focus of the stability study should be in demonstrating that the product is safe for consumption and that it will meet the labeled amount throughout the shelf life. An analysis of the product should identify any stability indicating parameters. Common parameters for cannabinoid products include:
Color and appearance
Content of any other labeled ingredient (ex. vitamins, minerals)
It is possible to justify not needing to test some parameters with previous data for similar products, literature data or product data. An example of product data can include the water activity of the product. If the water activity is sufficiently low it won’t support microbial growth and therefore microbial analysis is not required for the stability study.
The stability study design should include all products in the product type. The different strengths, flavors/fragrances and package types can be evaluated as a whole to determine if the evaluation of one representative product will support the stability of the entire product line. Screening studies can be utilized to identify the worst-case product, the product that is showing the most degradation at accelerated conditions.
A well-planned stability study will provide data necessary to demonstrate the safety and quality of the product throughout its shelf life. It can be designed in such a way to minimize cost and to bring added value to your product line.
Ask us to design a stability study for your range: email firstname.lastname@example.org or visit triveritylabs.com