Valaciclovir EP Impurity H;Valacyclovir EP Impurity H;Valaciclovir EP Impurity H HCl;2-[(2-amino-6-oxo-3H-purin-9-yl)methoxy]ethyl (2S)-2-aminopropanoate;Valacyclovir Impurity H (EP);L-Alanine, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)methoxy]ethyl ester;Valacyclovir Impurity 22;Valaciclovir Impurity H