RESUMO
Interferon-alpha2b (IFN α-2b) microspheres were prepared at various concentrations (5%, 10%, 15%, 20% and 25%) and viscosities (0.39, 0.6, 0.89 and 1.13 dL/g) of poly(lactic-co-glycolic acid) (PLGA) using double emulsion solvent evaporation. The optimal formulation of IFN α-2b microspheres was determined to be 0.89 dL/g PLGA, as assessed by the in vitro release test. The pharmacokinetics of IFN α-2b microspheres was investigated. Nine groups of rats were injected intramuscularly with three doses (0.5, 1 and 2 MIU) of commercial lyophilized IFNα-2b injection or IFN α-2b microspheres. At a dose of 0.5 MIU, the IFN α-2b microsphere released significantly longer than that of the IFN α-2b injection. At a dose of 2 MIU, each pharmacokinetics parameter of microspheres prepared with the IFNa-2b stock solution was manifestly greater than those of the injection. Our study indicated that the IFN α-2b microspheres prepared in 15% of 0.89 dL/g PLGA provided a sustained drug effect for up to 21 days in rats.
Assuntos
Portadores de Fármacos/química , Interferon-alfa/administração & dosagem , Interferon-alfa/farmacocinética , Ácido Láctico/química , Ácido Poliglicólico/química , Animais , Composição de Medicamentos , Emulsões/química , Liofilização , Humanos , Injeções Intramusculares , Interferon alfa-2 , Masculino , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacocinética , ViscosidadeRESUMO
By a double emulsion solvent evaporation method, interferon-alpha (IFN-alpha) microspheres were prepared with poly(lactide-co-glycolide) (PLGA) and their characteristics, such as morphology, drug loading, encapsulation efficiency, in vitro release and degradation were evaluated. The IFN-alpha microspheres were prepared by different viscosities from 0.17-1.13 dL g(-1) and concentrations between 5-25% of PLGA, which not only affected the drug loading and encapsulation efficiency of IFN-alpha microspheres, but also strongly influenced the in vitro release. With smooth and porous surface, the drug loading and encapsulation efficiency of the microspheres prepared by 15% 0.89 dL g(-1) PLGA were 7.736% and 77.38%, respectively. The DSC curve of microspheres indicated IFN-alpha was loaded inside the microspheres. The degradation of microspheres was homogeneous and the mass loss was over 80% in 6 weeks. The release profile of microspheres showed a sustained fashion and the IFN-alpha released from microspheres maintained its bioactivity for 7 days.
