Thymosin-loaded enteric microspheres for oral administration: preparation and in vitro release studies.
Int J Pharm
; 301(1-2): 41-7, 2005 Sep 14.
Article
em En
| MEDLINE
| ID: mdl-16009514
ABSTRACT
Thymosin, a water-soluble polypeptide compound, was encapsulated within enteric microspheres of acrylic acid resin II by modified oil in oil (o/o) emulsion solvent evaporation method. The mixture emulsifier composed of lecithin and Span 80 was critical to the formation of sphere-shaped thymosin microparticles. Optimizing process parameters, such as the volume ratio of organic solvent to water, initial drug feed and polymer concentration, resulted in high drug encapsulation efficiency of 89.7% (6% polymer concentration and 0.5% initial drug feed). In vitro release studies suggested that thymosin release from microspheres exhibited pH dependent profiles. For formulation with 6% polymer concentration and 0.5% initial drug feed, 68.7% thymosin was released within 4h in pH 6.8 PBS buffer, while only 6.5% was observed in acid medium.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Timosina
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article