Acyclovir is a guanosine analogue antiviral drug. Product Name Acyclovir Chemical Name Acycloguanosine; 9-[(2-Hydroxyethoxy)methyl] CAS Number 59277-89-3 Molecular Formula C8H11N5O3 Molecular Weight 225.21° C Storage Store in a tightly sealed container away from heat and direct light, and in a cool dry place.