1-Methyl-2- (methylsulphanyl)-1H-imidazole Hydrochloride;Methimazole Related Compound C as Hydrochloride;Thiamazole Impurity C as Hydrochloride;Methimazole USP Related Compound C as Hydrochloride;Thiamazole EP Impurity C as Hydrochloride;Fulvestrant Impurity 58;Thiamazole EP Impurity C HCl (Methimazole USP Related Compound C HCl)