Development and validation of a stability-indicating LC-UV method for the determination of doripenem and biapenem in pharmaceutical dosage forms

A stability-indicating LC assay method was developed and validated for the quantitative determination of doripenem and biapenem in pharmaceutical dosage forms in the presence of degradation products formed during forced degradation studies. An isocratic RP-HPLC method was developed with a C-18 (250 mm × 4.6 mm, 5 μm) column and 12 mM ammonium acetate-acetonitrile (96:4 υ/υ) as mobile phase. The flow rate of the mobile phase was 1.0 mL min-1 for doripenem and biapenem. The determination was carried out at the wavelength of 295 nm. The carbapenems were subjected to stress conditions of degradation in aqueous solutions including hydrolysis, oxidation, photolysis, and thermal degradation. The developed method was validated with respect to linearity, accuracy, precision, selectivity, and robustness.