Preparing a wound care device for regulatory review means submitting the results from your preclinical wound care study. Whether it’s a mesh implant for hernia repair or medicated dressing designed to speed up healing for diabetic patients, the wound care study will demonstrate to regulatory evaluators the device’s performance and safety. Because live animal models are used in these studies, careful planning is needed to ensure the trials begin on time and manage the costs.
Your APS team will design a wound care study based on the unique specifications of your device. Before you reach that phase, answering the following questions ahead of time can be a helpful aid when it comes to budgeting time and funds in preparation for these trials.
Which wound type is best for testing the device?
The wound test is critical for evaluating both the performance and the safety of the medical device. Depending on the medical device being tested, step one is creating the type of conditions it’s designed to treat. Start by thinking about the possible methods. Would it need a scrape or incision, or would the skin need to be excised? Another thing to consider is the thickness of the wound, and whether it’s excised down the fascia or into the muscle. Because thickness affects healing time, this will affect the duration of the study.
What size should the wound be?
The size of the product will influence the number of wounds needed for each animal model. When it comes to wound studies, it’s important to understand that control studies are also important in the evaluation of your device to compare healing and scarring. If the device covers a larger area relative to the size of the model, that can increase the number of animal models used in the study. For many medical devices designed to treat and heal wounds, the FDA has suggested a diameter of 3 cm for circular wounds, but a 2-x-2 cm wound can also be a good place to start for larger test models.
What is the treatment type?
A completed study requires providing enough test samples, along with other treatment types. First, factor in the amount of topical gel needed for wound dressing. Then, factor in the frequency of bandage changes needed over the course of the study. For example, at the start of healing, the dressing or wound filler will need to be changed more frequently than later stages as the wound bed develops.
How much technician time is needed?
To help account for the required technician time, factor in the number of bandage changes over the course of the study, with the consideration that test models are anesthetized for their safety, comfort, and cleanliness. The other consideration is the type of dressing, as certain types, such as negative pressure wound treatments, require 24/7 monitoring.
Have you met with the FDA?
Seeking preliminary feedback about your device from the Food and Drug Administration can help your team set the right endpoints and plan a wound care study that meets their requirements.
Here are a few questions to ask your FDA contact:
What’s the minimum number of animals needed?
As mentioned earlier, the device size and type will factor in to what the FDA finds acceptable.
Which animal model is recommended?
For many wound care studies, porcine models are preferred, because their skin is most human-like. For other studies, rabbit ears are optimal because their hypertrophic scarring can provide a good model for evaluating how the scar tissue behaves during the study. When it comes to devices geared for diabetic patients, the FDA may want to see results from a disease state model (i.e., a diabetic animal model).
What’s the minimum number of samples needed?
Again, factor in the number of test sites and controls. For example, ISO 10993 calls for 10 of each study article.
Still have questions on how to prepare for a wound care study? Contact us to learn more about how we can help you get your promising new product closer to market.