(αR,2R,4S)-4-Carboxy-α-[[[3-(2-chloro-6-fluorophenyl)-5-methyl-4-isoxazolyl]carbonyl]amino]-5,5-dimethyl-2-thiazolidineacetic Acid; [2R-[2α(R*),4β]]-4-carboxy-α-[[[3-(2-Chloro-6-fluorophenyl)-5-methyl-4-isoxazolyl]carbonyl]amino]-5,5-dimethyl-2-thiazolidineacetic Acid;

(5R)-Flucloxacillin Penilloic Acid is a metabolite and impurity of Flucloxacillin.