Stability of ceftazidime pentahydrate in medicinal preparations Biotum and Ceftim.

The influence of temperature and relative air humidity on the stability of ceftazidime in two different pharmaceutical preparations was investigated. The degradation of the substance studied was determined: (a) in dry air at 373, 378, 383, 388 and 393 K; (b) at air humidity RH = 76.4% at 323, 333, 343, 353 and 358 K; (c) in the humidity range 25.0 - 76.4% at 358 K. The decomposition of ceftazidime in these conditions is a first-order reaction relative to substance concentration. The kinetic and thermodynamic parameters of the degradation of ceftazidime were calculated and compared for the two pharmaceuticals. The study was conducted using the HPLC method on LiChrosorb RP-18 columns (250 x 4 mm) with 9% acetonitrile in 0.1 mole/L ammonium acetate as mobile phase and detection at 254 nm.