RESUMO
The influence of temperature and relative air humidity on the stability of two novel derivatives of daunorubicin: [(N-piperidine)methylene]daunorubicin hydrochloride and [(N-pyrrolidine)methylene]daunorubicin hydrochloride was investigated. The process of degradation was studied by using high-performance liquid chromatography with ultraviolet (UV) detection. The kinetic and thermodynamic parameters of degradation were calculated.
Assuntos
Antibióticos Antineoplásicos/química , Daunorrubicina/química , Química Farmacêutica , Cromatografia Líquida de Alta Pressão , Daunorrubicina/análogos & derivados , Estabilidade de Medicamentos , Umidade , Cinética , Espectrofotometria Ultravioleta , Tecnologia Farmacêutica/métodos , TemperaturaRESUMO
The influence of temperature and relative air humidity on the stability of cefaclor monohydrate in crystalline form and in its pharmaceutical preparations (oral suspension and slow release tablets) was investigated. The process of degradation was studied by using high-performance liquid chromatography with ultraviolet (UV) detection, as described in the monograph of cefaclor in European Pharmacopoeia. The degradation of cefaclor monohydrate in substance, in oral suspension and tablets at relative air humidity RH > 50% is a first-order autocatalytic reaction relative to substrate concentration, while at 0% RH the degradation of cefaclor in substance is a first-order reaction relative to substrate concentration. The kinetic and thermodynamic parameters of degradation were calculated.
Assuntos
Antibacterianos/química , Cefaclor/química , Cromatografia Líquida de Alta Pressão , Cristalização , Preparações de Ação Retardada , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Europa (Continente) , Umidade , Farmacopeias como Assunto , Comprimidos , Temperatura , TermodinâmicaRESUMO
The stability of cefprozil in oral suspension CEFZIL was studied by means of the stress stability test. Degradation was evaluated by using an HPLC method with UV detection (280 nm), as described in the monograph of Cefprozil for Oral Suspension, in USP 25. At increased temperature and relative air humidity the degradation of cefprozil in CEFZIL occurs as reversible-consecutive and parallel reactions. The reversible reaction of isomerization is approx. 10 times faster than the parallel degradation reaction of individual isomers. The first-order rate constants of the parallel reactions Z-cefprozil --> product 1 and E-cefprozil --> product 2 were determined at RH = 76.4% at T = 333, 338, 343, 348 and 353 K, and at T = 333 K and RH = 50.9, 66.5, 76.4 and 90.0%. The thermodynamic parameters E(a), deltaH(double dagger) and deltaS(double dagger) of these reactions were calculated.
Assuntos
Cefalosporinas/química , Administração Oral , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Humanos , Umidade , Suspensões , Temperatura , CefprozilRESUMO
The influence of temperature and relative humidity on the stability of cefetamet pivoxil (CFP) and its hydrochloride (CFP.HCl) in solid phase was investigated. The process of degradation was studied using HPLC with UV detection. The degradation of CFP and CFP.HCl occurring at air humidity RH>50% is an autocatalytic first-order reaction with respect to substrate concentration, while at 0% relative humidity of the ambient air it is a first-order reaction relative to substrate concentration for CFP.HCl, and a reversible first-order reaction for CFP. The rate constants (k) were determined in dry air at 373 K, 378 K, 383 K, 388 K and 393 K; at air humidity RH = 76.4% at 333 K, .343 K, 353 K, 363 K and 373 K; and at 363 K at air humidity RH>50%. The kinetic and thermodynamic parameters of the degradation were calculated.