Joint poster with Urgo: Supporting hypoallergenicity claims for Medical Wound Dressings
Supporting industry decision-making and hypoallergenicity claims using an experimental setup combining GARD®skin Medical Device and Dose-Response protocols.
Presented at 2025 Eurotox
Conclusion
This case study demonstrates how NAMs like GARD® can be effectively integrated into product development for assessing skin sensitization potential in medical device extracts. It enables evidence-based decision-making and supports hypoallergenic claims, without the use of animal testing.
Abstract
Biocompatibility testing is a crucial part of medical device safety assessments both for regulatory acceptance of finished products but also within the developmental pipelines of novel devices. Along with cytotoxicity and irritation, skin sensitization is a key toxicological endpoint that must be assessed for all devices. While testing for the two former endpoints is partly conducted in vitro, traditional animal experimentations for skin sensitization testing are still routinely conducted. Thus, validation and implementation of New Approach Methods (NAMs) remains a prioritized goal of the medical device industry.
The GARDskin method (OECD 442E) is a NAM for hazard assessment of skin sensitizers based on test chemical exposure of dendritic cell-like cells followed by a genomic readout. Several method adaptations have been proposed in order to address specific needs of various industry segments. Such adaptations include the GARDskin Dose-Response (DR) method, which facilitates quantitative assessment of sensitizing potency, and the GARDskin Medical Device (MD) method, which facilitates testing of solid materials in accordance with ISO 10993 standards.
Here we report an experimental setup combining the protocols of above-mentioned GARDskin adaptations used to evaluate the relative hypoallergenicity of two sensitive skin dressings: a candidate product and a marketed comparative product. The extraction from the solid test items was performed according to ISO 10993-12, but with an increased test item to extraction vehicle ratio of 6x. The oversaturated extracts were subsequently subjected to serial dilution facilitating dose-response testing in order to evaluate, assess and compare the test items’ relative skin sensitizing potentials.
The results concluded that both test items were classified as non-sensitizers. Due to the oversaturation extraction procedure, otherwise adhering to the ISO 10993-12 standards, the results are noteworthy. Indeed, due to the manyfold increase in material to vehicle ratio, labelling the tested skin dressings as hypoallergenic, or otherwise suitable for sensitive use, may be supported by the data. Furthermore, evaluation of the relative difference between the two test items concluded that the comparative test item induced elevated response values at the highest tested concentration, whereas the candidate test item did not. As such, it could be argued that the candidate product can be claimed as hypoallergenic similarly to the comparative product.
In summary, this experimental setup combining GARDskin MD and GARDskin DR protocols can successfully be used to support claims of hypoallergenicity of medical devices, as well as comparing candidate products with respect to their relative skin sensitizing potential. These results illustrate how such strategies can be routinely integrated in the development of novel devices giving data for critical decision-making without resorting to animal experimentation for regulatory approval.
