5 documents found, page 1 of 1
Insulin release from alginate microspheres reinforced with dextran sulfate
Silva, Catarina M.; Ribeiro, António J.; Veiga, Francisco; Sousa, Adriano deIn a previous study, insulin was efficiently encapsulated in alginate microspheres using an emulsification /internal gelation process. However, these microspheres showed a high insulin release at gastric pH, exposing the protein to the harsh conditions of the stomach. In this study, our attempt was to improve insulin release profile by reinforcing the alginate matrix with dextran sulfate (DS). The size distribu...
Insulin encapsulation in reinforced alginate microspheres prepared by internal ...
Silva, Catarina M.; Ribeiro, António J.; Ferreira, Domingos; Veiga, FranciscoInsulin-loaded alginate microspheres prepared by emulsification/internal gelation were reinforced by blending with polyanionic additive polymers and/or chitosan-coating in order to increase the protection of insulin at simulated gastric pH and obtain a sustained release at simulated intestinal pH. Polyanionic additive polymers blended with alginate were cellulose acetate phtalate (CAP), Eudragit® L100 (EL100), ...
Alginate microspheres prepared by internal gelation: Development and effect on ...
Silva, Catarina M.; Ribeiro, António J.; Figueiredo, Isabel Vitória; Gonçalves, Alexandra Rocha; Veiga, FranciscoRecombinant human insulin was encapsulated within alginate microspheres by the emulsification/internal gelation technique with the objective of preserving protein stability during encapsulation procedure. The influence of process and formulation parameters was evaluated on the morphology and encapsulation efficiency of insulin. The in vitro release of insulin from microspheres was studied under simulated gastro...
Administração oral de peptídeos e proteínas: II. Aplicação de métodos de microe...
Silva, Catarina M.; Ribeiro, António; Ferreira, Domingos Carvalho; Veiga, FranciscoA escolha de um método de Microencapsulação adequado para promover o aumento da biodisponibilidade oral de fármacos peptídicos depende das características físico-químicas do fármaco a encapsular, das condições operacionais e dos polímeros utilizados. Nesta abordagem é feita uma avaliação dos diversos métodos de Microencapsulação e sua aplicação na administração oral de peptídeos e proteínas. As técnicas de Micr...
Administração oral de peptídios e proteínas: I. Estratégias gerais para aumento...
Silva, Catarina M.; Ribeiro, António; Ferreira, Domingos; Veiga, FranciscoExistem, atualmente, centenas de peptídios e proteínas com ação terapêutica. Os obstáculos inerentes à sua administração oral têm impulsionado a investigação de estratégias capazes de os ultrapassar. Nesta revisão são abordados estes dois aspectos. A microencapsulação, pela sua versatilidade, sobressai entre as demais estratégias, afirmando-se como escolha potencial na administração oral de fármacos peptídicos....