Lapatinib-d7 dihydrochloride is the deuterium labeled Lapatinib dihydrochloride. Lapatinib (GW572016) dihydrochloride is a potent inhibitor of the ErbB-2 and EGFR tyrosine kinase domains with IC50 values against purified EGFR and ErbB-2 of 10.2 and 9.8 nM, respectively[1].