Comparison of in chemico skin sensitization methods and development of an in chemico skin photosensitization assay

Abstract

US), recommend multiple integrated testing strategies (ITS) using non-animal test batteries that combine in silico, in chemico, and in vitro methods to identify skin allergens (EURL ECVAM,

Innovative Strategies for Photoallergy Assessment: Breaking Free from Animal Models in Cosmetic Ingredient Development

“…These studies can be useful for understanding certain aspects of photobinding steps that will help researchers to design future potential in silico models, but do not provide real progress in the field of photosafety assessment. The other four adapt ADRA [44,45] or DPRA [42,44,46] assays to identify contact sensitizers by coupling UVA lamps. The assays proved to be transferable among laboratories experienced in conducting high-performance liquid chromatography analysis [61].…”

“…The assays proved to be transferable among laboratories experienced in conducting high-performance liquid chromatography analysis [61]. Taking into consideration that among the four studies, almost 70 different chemicals besides allergen mixtures and herbicide formulations had been assessed, it has been proven that the volume of reaction [42], irradiation and time of incubation [44] can be lowered, and therefore these photoassays are promising tools for photosafety assessment.…”

“…In this sense, ten articles have previously classified the chemicals and compounds used to validate their potential predictive capacity into photoirritants, photoallergens (or photosensitizers) and non-phototoxic agents, and in three of them, the non-phototoxic agents were identified as irritants or allergens. In two cases, the authors only refer to phototoxicity because they used the information obtained by the NRU 3T3 PT that only allows classification among phototoxic and non-phototoxic agents [44] or because the phototoxic chemicals used are considered both phototoxic and photoallergenic [42]. Finally, Stieffel and Schwack [36] did not provide any classification at all.…”

Development of photo‐amino acid derivative reactivity assay: a novel in chemico alternative method for predicting photoallergy

“…However, as the ADRA is superior to DPRA in many aspects as described above, establishing a test based on ADRA is expected to enable the efficient evaluation of the photoallergy potential of compounds with various properties. Patel et al () have suggested the usefulness of photo‐DPRA and photo‐ADRA by applying DPRA and ADRA. However, because the photo‐ADRA reported by them requires the test chemical solution to be prepared at 100 mM, similar to DPRA, the advantages, such as solubility and precipitation of test chemical in reaction buffer, of preparing the test chemical solution at 1 mM in photo‐ADRA, as proposed by us, may be lost.…”