Hydroxychloroquine (sulfate) (Standard) is the analytical standard of Hydroxychloroquine (sulfate). This product is intended for research and analytical applications. Hydroxychloroquine sulfate (HCQ sulfate) is a synthetic antimalarial agent which can also inhibit Toll-like receptor 7/9 (TLR7/9) signaling. Hydroxychloroquine sulfate is efficiently inhibits SARS-CoV-2 infection in vitro[1][2][3].