title: STABILITY OF CEFPIROME SULFATE IN AQUEOUS SOLUTIONS.
abstract: The influence of pH on the stability of cefpirome sulfate was investigated in the pH range of 0.44 - 13.00. The degradation of cefpirome sulfate as a result of hydrolysis was a pseudo-first-order reaction. General acid-base hydrolysis of cefpirome sulfate was not observed. In the solutions of hydrochloric acid, sodium hydroxide, acetate, borate and phosphate buffer, k(obs) = k(pH) because specific acid-base catalysis was observed. Specific acid-base catalysis of cefpirome sulfate consisted of the following reactions: hydrolysis of cefpirome sulfate catalyzed by hydrogen ions (kH+), hydrolysis of dications (k₁H₂O) monocations (k₂ H₂O), zwitter ions (k₃H₂O) and monoanions (k₄ H₂O) of cefpirome sulfate under the influence of water. The total rate of the reaction was equal to the sum of partial reactions k(pH) = kH+ x aH+ + kH₂O x f₁ + k₂H₂O x f₂ + k₃H₂O x f₃ + k₄ H₂O x f₄. Based on the dependence k(pH) = f(pH) it was found that cefpirome sulfate was the most stable in aqueous solutions in the pH range of 4-6.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Zalewski
authors.forename: Anna
authors.initials: A
authors.lastname: Jelińska
authors.forename: Magdalena
authors.initials: M
authors.lastname: Paczkowska
authors.forename: Piotr
authors.initials: P
authors.lastname: Garbacki
authors.forename: Alicja
authors.initials: A
authors.lastname: Talaczyńska
authors.forename: Piotr
authors.initials: P
authors.lastname: Stfpniak
authors.forename: Judyta
authors.initials: J
authors.lastname: Cielecka-Piontek
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002511:Cephalosporins / Q000737:chemistry*; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D012996:Solutions; D000097572:Cefpirome
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D012996:Solutions; D000097572:Cefpirome