Hydrogen and halogen bonds in drug-drug cocrystals of X-uracil (X = F, I) and lamivudine: extended quadruplex and layered assemblies

We report drug-drug cocrystals of the cytotoxic chemotherapy drugs 5-fluoro (5FU)/iodouracil (5IU) and the antiretroviral lamivudine (3TC). The cocrystal 2(5FU)·(3TC) is sustained by hydrogen bonds to generate a three-dimensional (3D) network while halogen bonds in the cocrystal (5IU)·(3TC) effectively disrupt hydrogen bonds to form layered assemblies.