Valaciclovir EP Impurity FDTXSID308585564-Methylbenzene-1-sulfonic acid--2-hydroxyethyl valinate (1/1)2-hydroxyethyl 2-amino-3-methyl-butanoate;4-methylbenzenesulfonic acidValacyclovir EP Impurity F2-Hydroxyethyl L-valinate tosylateValacyclovir USP Related Compound FValaciclovir EP Impurity F TosylateValaciclovir Related Compound F (USP)L-Valine 2-Hydroxyethyl Ester TosylateValacyclovir Related Compound F as TosylateValaciclovir impurity F para-toluenesulfonate