Analysis of DPRA (Direct Peptide Reactivity Assay) for Skin Sensitization Testing Using Prominence™-i

Introduction

Animal bioassay involving the use of guinea pigs or mice was once the mainstream method of skin sensitization testing. However, a total ban on animal testing of cosmetics enacted in the EU in 2013 made it necessary to establish alternative testing methods which do not use animals. DPRA (direct peptide reactivity assay) is one of these alternative methods used to evaluate the potency of skin sensitization by examining the reactivity between a test chemical and peptides. This method uses two types of peptides, one containing cysteine and another containing lysine, which are mixed and reacted with the test chemical for 24 hours before using HPLC to determine the percent peptide depletion. The skin sensitization of the test chemical is evaluated from the determined percent depletion value of each peptide. In this article, we performed an analysis based on "TG 442C OECD GUIDELINE FOR THE TESTING OF CHEMICALS In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA)". The Prominence-i integrated high performance liquid chromatograph (PDA model) was used as the analytical instrument. The rack in the autosampler of this instrument was used to perform 24-hour incubation of the test chemical and peptides. The Shim-pack^TM HR- ODS (100 mm L. × 2.1 mm i.d., 3 μm) was used for the column.

February 25, 2019 GMT