Oroxcell – DPRA with LC-MS/MS, a reliable method for sensitization-potential assessment of complex mixtures.

DPRA with LC-MS/MS : A way forward for botanical extracts.

The DPRA assay is a widely used test to identify potential haptens that undergo a chemical reaction with endogenous proteins, the first key event of skin sensitization. It is described in the OECD Test Guideline 442C and exhibits state-of-the-art prediction performance levels, especially when combined with other in vitro sensitization assays.

However, the DPRA 442C assay has some limits, mainly linked to the technology employed. One of these limits is coming from the unforeseeable interference of the test item in the LC-UV detection involved in the assay, which is of particular relevance when testing mixtures of substances.

In response, Oroxcell is now offering this assay based on LC-MSMS to guarantee a highly specific detection of the native model peptides, based on both the retention time and their structure specific fragmentations, thereby significantly reducing the risk of interference-related test failure and false positive results.
More interestingly, this technique has proved to be robust and particularly effective when assessing sensitization potential of complex mixtures of substances as botanical extracts that are difficult to assess with conventional in vitro methods.

This work exemplifies Oroxcell’s commitment to and investment in alternative methods development and validation-in keeping with the principles of the EU Cosmetics Directive 7^th Amendment and REACH regulations.

Now, the DPRA LC/MSMS assay is available under GLP conditions. Please feel free to contact us for more information.

Eric ANDRES
Head of Life Science Department at Oroxcell