Chloroquine (dihydrochloride) (Standard) is the analytical standard of Chloroquine (dihydrochloride). This product is intended for research and analytical applications. Chloroquine dihydrochloride is an antimalarial and anti-inflammatory agent widely used to treat malaria and rheumatoid arthritis. Chloroquine dihydrochloride is an autophagy and toll-like receptors (TLRs) inhibitor. Chloroquine dihydrochloride is highly effective in the control of SARS-CoV-2 (COVID-19) infection in vitro (EC50=1.13 µM)[1][2][3][4].