Testing cosmetic wound care products
When it comes to wound care, proderm offers claim support studies for cosmetics intended for use on wound or skin with compromised skin barrier. Also, some physical properties of medical devices intended for wound care can be assessed outside the regulatory purview of the medical device regulation. Technical parameters include adhesion force, water resistance and similar claims. Sometimes, it is not easy to know what the regulatory requirements for your study are - proderm will be happy to assist you in finding the best way to test your product and support your claim!
In the following we would like to describe the abrasion wound model in more detail, as this is an approach we quite frequently utilize to assess not only cosmetic product effects on wounds.
The abrasive wound model
In this superficial wound model, our trained technicians will induce a wound of approximately 2 cm2 by scrubbing the skin in the open area of a template with a hand brush (autoclaved). The skin will be scrubbed until most of the epidermal layer is removed and the surface shows glistening and there is homogeneous punctual bleeding over the whole test area.
All investigations are performed in rooms that are completely air-conditioned, especially equipped for the above described tests after a defined period of acclimation of the subjects. This ensures constant conditions, which is important when measuring things like trans- epidermal water loss. Transepidermal water loss (TEWL) is a non-invasive method to measure the integrity of stratum corneum barrier function and is regarded as a sensitive parameter for skin barrier damage. TEWL will be measured with a Tewameter. Briefly, the measuring principle is based on the determination of the water vapor gradient between two temperature sensors and two hygrosensors placed at a defined distance perpendicular to the skin. If TEWL values are consistent over time, the skin barrier remains intact. An increase in TEWL values indicates damage to the skin barrier function.
The wound healing progress is captured via DermLite macroscopic images of test areas, which are captured using a high resolution digital camera Canon Mark 5 IID. The images will be provided to the sponsor for photo documentation at the end of the study and can be used to reliably quantify the wound area for statistical analysis.
Abrasion model study design
The following table presents an abrasion model study design as typically conducted at proderm.
Aim | Assessment of the efficacy of a product on the volar forearms to improve the wound healing of minor superficial wounds. | |
Parameters | P1 | Measurement of skin barrier damage by TEWL [Tewameter] |
P2 | Subject's assessment of wound quality by ranking | |
P3 | Macro photography | |
P4 | Wound area determination from images | |
P5 | Cosmetic Outcome (Assessed by subject) | |
Test product | Wounds will be treated with the test product, reference product or remain untreated. Occlusive or semi occlusive treatment will be applied by technicians for the first six days to reduce infection risk. After that, the product will be applied twice daily by the subjects at home. | |
Test area | Volar forearms, up to 4/6 areas | |
Test procedure | Screening | Informed consent and enrollment by Physician |
Day 1 | Acclimation, P1; P2, induction of abrasive wounds, P1, P2,P3, product application by technician | |
Day 2-6 | Patch removal, acclimation, P1, P2, P3, product application by technician, distribution of products for home-use on day 6 | |
Day 7-21 | Open application of products twice daily by subjects at home | |
Day 8, 10, 12, 15, 18, 22, 26 | Acclimation, P1 and P2, P3, return of test products on day 26 | |
Assessment after the end of the study | P4 and P5 |
Would you like to learn more?
Watch our webinar 'Wounds and wound healing properties'.
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