ChemiCal stability of Ceftriaxone by a validated stability-indiCating liquid ChromatographiC method

The chemical stability of ceftriaxone for injection reconstituted with water was studied at different storage conditions by a validated stability-indicating ion-pair liquid chromatographic method. The study was performed on ceftriaxone for injection samples obtained from two pharmaceutical laboratories, at three different temperatures: 23 oC ± 2 oC, + 8 oC ± 1 oC and 20 oC ± 0.5 oC, over 26 days, 55 days, and 76 days, respectively. Chromatographic separation was achieved on a RP-18 column, using a mobile phase consisting of 250 mL acetonitrile, 50 mL phosphate buffer (pH 7.4; 0.1M), 3.2 g tetrabutylammonium bromide made up to a volume of 1 L with water, at a flow rate of 1.0 mL min−1 and UV detection at 260 nm. The stability-indicating capability of the assay was established by forced degradation studies under hydrolysis, high temperature and photolysis. The developed method was specific, stability indicating, accurate and precise for ceftriaxone determination. At room temperature and at + 8 oC the degradation of ceftriaxone followed first-order kinetics and the samples were chemically stable for at least 4 and 41 days respectively. At 20 oC the concentration of all samples remained higher than 90% of the original concentration. Degradation of ceftriaxone was higher at room temperature; therefore lower storage temperatures improved the chemical stability of ceftriaxone for injection in water.