Valsartan Impurity 18 is chemically (S)-2-[N-((2'-Cyanobiphenyl-4-yl)methyl)pentanamido]-3-methyl butanoic acid. Valsartan Impurity 18 is supplied with detailed characterization data compliant with regulatory guideline. Valsartan Impurity 18 can be used for the analytical method development, method