Synonyms: Ganciclovir Imp. F (EP),Aciclovir Imp. B (EP), Valaciclovir Hydrochloride Imp. A (EP), Valaciclovir Imp. A (EP), 2-Amino-1,9-dihydro-6H-purin-6-one, 2-Amino-1,7-dihydro-6H-purin-6-one, Valaciclovir Hydrochloride Anhydrous Imp. A (EP), Guanine, Ph Eur Valaciclovir Impurity A, AH 13779, Ph Eur Aciclovir Impurity B, 559U81, Guanine, Aciclovir Impurity B, Ganciclovir Impurity F, Valaciclovir Hydrochloride Hydrate Impurity A, Valaciclovir Hydrochloride Impurity A, Valaciclovir Impurity A, Guanine (USP).