Ritonavir EP Impurity - I

(5S,8S,10S,11S)-1-(2-Ethyl-4-thiazolyl)-10-hydroxy-2-methyl-5-(1-methylethyl)-3,6-dioxo-8,11-bis(phenylmethyl)-2,4,7,12-tetraazatridecan-13-oic Acid 5-Thiazolylmethyl Ester; 1,3-Thiazol-5-ylmethyl ((1S,2S,4S)-4-(((2S)-2-(((((2-ethyl-1,3-thiazol-4-yl)methyl)(methyl)amino)carbonyl)amino)-3-methylbutanoyl)amino)-2-hydroxy-5-phenyl-1-(phenylmethyl)pentyl)carbamate;