PDC-APB
PDC-APB, or 3-pentadecyl-1,2-phenylene bis(4-(4-aminophenyl)butanoate), is a drug candidate under evaluation to determine if it might protect against contact dermatitis caused by urishiol from poison ivy, poison oak, and poison sumac. History 

The compound is one of a class of compounds developed through University of Mississippi research by Mahmoud ElSohly, Waseem Gul, and Mohammad Khalid Ashfaq. Work on the compound is ongoing under Hapten Sciences, who licensed the university's research in 2010. Evaluation as a drug candidate 

The compound has been evaluated in two Phase I clinical trials, and a third Phase I randomized controlled trial, with a secondary objective of evaluating the effect of treatment on urishiol sensitivity, is due to be completed in December 2022. See also
Urushiol-induced contact dermatitis

References

Dermatologic drugs