Design and mechanism of on-off pulsed drug release using nonenteric polymeric systems via pH modulation.
AAPS PharmSciTech
; 12(1): 46-55, 2011 Mar.
Article
en En
| MEDLINE
| ID: mdl-21161457
ABSTRACT
The aim was to design a pH-sensitive pulsatile drug delivery system that allows for an on-off pulsed release of a drug using polyacrylic acid (PAA) blended with ethyl cellulose (EC) in different ratios. PAA, a polyelectrolyte polymer, exhibits a highly coiled conformation at low pH but a highly extended structure at high pH. Fumaric acid, which is an internal acidifying agent, was incorporated into the hydroxypropyl methylcellulose-based core tablets to create an acidic microenvironmental pH (pH(M)). The concentration of fumaric acid inside the core tablet and the ratio of PAA/EC in the coating layer were very crucial in modulating drug release behaviors. When the fumaric acid was retained in the core tablet, it gave a more acidic pH(M), so that the PAA was kept in a highly coiled state in the coated film, which hindered drug release ("off" release pattern). Interestingly, the release profiles of the drug and fumaric acid from coated tablets showed the on-off pulsed pattern upon dissolution. Imaging analyses using scanning electron microscopy, near-infrared imaging, confocal laser scanning microscopy, and Fourier transform infrared spectroscopy confirmed this on-off release behavior of the drug and fumaric acid from coated tablets.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Terbutalina
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Broncodilatadores
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Preparaciones de Acción Retardada
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Fumaratos
Idioma:
En
Revista:
AAPS PharmSciTech
Asunto de la revista:
FARMACOLOGIA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Corea del Sur