Abstract
Two simple and cost effective spectrophotometric methods are described for the determination of Doripenem and Ertapenem in pure form and in pharmaceutical formulations. The method is based on the formation of green colored chromogen when the drug reacts with 3-methyl-2-benzothiazolinone hydrazone (MBTH) in presence of an oxidizing agent FeCl3. The colored species has an absorption maximum at 397 nm for Doripenem (Method A) / Ertapenem (Method B) and obeys beer’s law in the concentration range of 0.04-0.16 µg/mL for both Doripenem and Ertapenem. The apparent molar absorptivities were 0.0145, 0.0108 and sandell’s sensitivity was 1x10-3 for both Doripenem and Ertapenem. The slopes were 0.3371±0.01885, 0.2611 ± 0.004327, and intercept of the equation of the regression line are 0.2266 ± 0.0070, 0.1997 ± 0.0026 for Doripenem and Ertapenem respectively. The optimum experimental parameters for the reaction have been studied and the validity of the described procedure was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed method was successfully applied for the determination of Doripenem and Ertapenem in pharmaceutical formulations.
