The UV-derivative spectrophotometry for the determination of doripenem in the presence of its degradation products

A spectrophotometric method was developed for the quantitative determination of doripenem in pharmaceutical dosage form (DORIBAX) in the presence of its degradation products. The first-derivative with or without the substration technique, depending on formed products degradation was applied (λ = 324 nm). The method was linear in the range concentration (0.42–11.30) × 10−2 mg L−1 (r = 0.9981), the limits of detection and quantification were 7.60 and 45.0 μg L−1, respectively. Recovery of doripenem ranged from 99.85 to 102.97% in pharmaceutical dosage form. This method had a good precision (RDS from 0.35 to 2.93%). The observed rate constants for doripenem degradation were comparable to those obtained in recommended HPLC method.