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https://hdl.handle.net/10316/27826
Título: | Drug release mechanisms of chemically cross-linked albumin microparticles: effect of the matrix erosion | Autor: | Sitta, Danielly L. A. Guilherme, Marcos R. Silva, Elisangela P. da Valente, Artur J. M. Muniz, Edvani C. Rubira, Adley F. |
Palavras-chave: | Albumin; Drug delivery; Emulsion; Erosion; Microparticles; Drug release kinetics | Data: | 1-Out-2014 | Editora: | Elsevier | Citação: | SITTA, Danielly L. A. [et. al] - Drug release mechanisms of chemically cross-linked albumin microparticles: effect of the matrix erosion. "Colloids and Surfaces B: Biointerfaces". ISSN 0927-7765. Vol. 122 (2014) p. 404–413 | Título da revista, periódico, livro ou evento: | Colloids and Surfaces B: Biointerfaces | Volume: | 122 | Resumo: | Albumin (BSA) microparticles were developed as a biotechnological alternative for drug delivery. Vitamin B12 (Vit-B12) was used as a model drug. The microparticles were obtained from maleic anhydride-functionalized BSA and N′,N′-dimethylacrylamide (DMAAm) in a W/O emulsion without and with PVA. The microparticles produced at 15 min of stirring without PVA showed the best results in terms of size, homogeneity, and sphericity. In such a case, BSA played a role as a surface active agent, replacing PVA. For longer stirring times, BSA was unable to act as an emulsifier. These microparticles showed an uncommon release profile, consisting of a two-step release mechanism, at the pH range studied. Considering that a two-step release mechanism is occurring, the experimental data were adjusted by applying modified power law and Weibull equations in order to describe release mechanism n and release rate constant k, respectively. Each one of the release stages was related to a specific value of n and k. The second stage was driven by a super case II transport mechanism, as a result of diffusion, macromolecular relaxation, and erosion. A third model, described by Hixson–Crowell, confirmed the erosion mechanism. Vit-B12 diffusion kinetics in aqueous solutions (i.e., without the microparticles) follows a one-step process, being k dependent on the pH, confirming that the two-step release mechanism is a characteristic profile of the developed microparticles. The microparticles released only 2.70% of their initial drug load at pH 2, and 58.53% at pH 10. | URI: | https://hdl.handle.net/10316/27826 | ISSN: | 0927-7765 | DOI: | 10.1016/j.colsurfb.2014.07.014 | Direitos: | openAccess |
Aparece nas coleções: | FCTUC Química - Artigos em Revistas Internacionais |
Ficheiros deste registo:
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Drug release mechanisms of chemically.pdf | 2.57 MB | Adobe PDF | Ver/Abrir |
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