Repaglinide Impurity 16 (4-Carboxy-3-ethoxy)phenyl Acetic Acid (Repaglinide Impurity) Flurbiprofen Related Impurity 1 Flurbiprofen Impurity 15 (2-FLUORO-4-BIPHENYL)ACETIC ACID 2,4-Difluoronitrobenzene 4-Acetyl-2-fluorobiphenyl Flurbiprofen Related Impurity 2 Flurbiprofen alpha-Methyl-4-biphenylacetic acid