RESUMEN
The aim of this study was to produce cinnarizine loaded Eudragit(®) L100-55 microparticles by coacervation technique in order to achieve pH responsive drug release using hydroxypropyl methycellulose (HPMC) as stabilizer. The effect of enteric polymer: HPMC ratio on properties of microparticles was investigated with regard to particle size distribution, morphology, yield, encapsulation efficiency, in vitro drug release profiles and interaction between cinnarizine and Eudragit(®) L100-55. High drug encapsulation efficiency was seen in all microparticles. Particle diameter increased when the enteric polymer content was higher relative to HPMC. In vitro dissolution studies demonstrated that the drug release from the microparticles was dependent upon enteric polymer: HPMC ratio and particle size distribution. At the ratio of at least 3.75:1 of enteric polymer: HPMC, drug release was suppressed most significantly in low pH (hydrochloric acid as medium) while rapid drug release was observed in pH 7.4.
Asunto(s)
Cinarizina/administración & dosificación , Antagonistas de los Receptores Histamínicos H1/administración & dosificación , Tecnología Farmacéutica , Resinas Acrílicas/química , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Cinarizina/química , Concentración de Iones de Hidrógeno , Derivados de la Hipromelosa , Metilcelulosa/análogos & derivados , Metilcelulosa/química , Tamaño de la Partícula , Solubilidad , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
We have used a silica - PEG based bionanoconjugate synthetic scheme to study the subtle connection between cell receptor specific recognition and architecture of surface functionalization chemistry. Extensive physicochemical characterization of the grafted architecture is capable of capturing significant levels of detail of both the linker and grafted organization, allowing for improved reproducibility and ultimately insight into biological functionality. Our data suggest that scaffold details, propagating PEG layer architecture effects, determine not only the rate of uptake of conjugated nanoparticles into cells but also, more significantly, the specificity of pathways via which uptake occurs.