Development of a competitive indirect ELISA for high-throughput screening of hydrocortisone in cosmetic sample

ABSTRACT Hydrocortisone (HYD) is one of the corticosteroids that illegally used in cosmetic products, which could lead to a potential health problem. In this work, HYD was conjugated to bovine serum albumin via a succinic anhydride spacer arm to yield an immunogen. New Zealand rabbits were immunized to obtain a polyclonal antibody against HYD. Based on the pAb, a heterologous competitive indirect enzyme-linked immunosorbent assay (ciELISA) by using progesterone carboxylic acid as a competitive hapten was developed. The assay showed an IC50 of 0.50？ng mL？1, detection limit of 0.04？ng mL？1 and a linear range of 0.10–2.00？ng？mL？1. The assay was applied to determine HYD in cosmetic samples. Recoveries from 82.5% to 118.9% and CV from 1.3% to 9.5% were obtained using a simple pretreatment. Good correlation between the results of ciELISA and standard LC–MS/MS was obtained, suggesting its potential usage in HYD monitoring in cosmetic samples