Development and validation of spectrophotometric methods for carbapenems in pharmaceutical dosage forms

Simple and sensitive spectrophotometric methods have been developed for the determination of meropenem (MRPM) and doripenem (DRPM). These methods are based on the reduction of Fe(III) into Fe(II) by the drugs and their subsequent prussian blue color formation (λ_max 720 nm) with hexacyanoferrate (III), red color formation (λ_max 510 nm) with 1,10-phenanthroline and red color formation (λ_max 520 nm) with 2,2′-bipyridyl in the methods A, B, and C, respectively. Regression analysis of Beer’s plots showed good correlation for MRPM and DRPM in the concentration range (μg/mL) 0.5–6, 2–10; 2–10, 2–14, and 2–18, 1–8 for the methods A, B, and C, respectively.