5th International Conference on Advances in Chemistry and Applied Chemistry (ICACAC-5) P56: Novel Spectrophotometric Microdetermination of Carbapenem Antibiotics Derivatives in Pharmaceutical Formulations Homoda A. M.A., Kamel M. S., Khaled E. Microanalysis Laboratory Applied Organic Chemistry Dept., National Research Centre, Dokki, Giza 12622, Egypt Abstract Accurate and sensitive spectrophotometric method was described for the determination of three carbapenem antibiotics namely; imipenem, meropenem and ertapenem in their pharmaceutical preparations. The proposed method was based on the formation of colored tris (ophenanthroline)-iron(II) complex (ferroin) [FPL] or Fe (II)- 2,2‫״‬bipyridyl complex [FBL] upon reaction of the tested drugs with the corresponding iron (III)-o-phenanthroline or Fe (III)- 2,2‫״‬- bipyridyl complexes in acetate buffer of pH 4. Absorbances of the formed colored complexes were measured at 510 and 520 nm for [FPL] and [FBL], respectively against their reagent blank. Optimizations of the experimental conditions such as effect of pH, reagent concentration, reaction time and temperature as well as stability of the formed colored species were discussed in details. Linear calibration curves were obtained within the ranges from 0.2 to 10 and 0.5 to 10 and 0.5 to 10 µg mL-1 for Organized by Chemical Industries Research Division-National Research CentreDokki, Cairo, Egypt 1 5th International Conference on Advances in Chemistry and Applied Chemistry (ICACAC-5) the aforementioned drugs in the same order. The proposed method was successfully applied to the determination of imipenem meropenem and ertapenem in their pharmaceutical formulations without interference by the common co-formulated substances. Statistical comparison of the results with the reference method showed good concurrence and indicated no significant difference in accuracy and precision. Organized by Chemical Industries Research Division-National Research CentreDokki, Cairo, Egypt 2