On the employment of λ-carrageenan in a matrix system. II. λ-Carrageenan and hydroxypropylmethylcellulose mixtures
1994; Elsevier BV; Volume: 30; Issue: 2 Linguagem: Inglês
10.1016/0168-3659(94)90264-x
ISSN1873-4995
AutoresMaria Cristina Bonferoni, Silvia Rossi, M. Tamayo, José Luís Pedraz, A. Domínguez‐Gil, Carla Caramella,
Tópico(s)Polysaccharides Composition and Applications
ResumoThe suitability of λ-carrageenan-hydroxypropylmethylcellulose (HPMC) matrices for the controlled release of two basic drugs (salbutamol sulphate and chlorpheniramine maleate) has been assessed. The influence that the amounts of the two polymers and their ratios have on drug release profiles was studied. Percentages of λ-carrageenan as high as 40% in the matrix gave rise to good early control of drug release, resulting in release profiles close to linearity. The overall release rate was usually higher in buffer at pH 1.2 than at pH 6.8, indicating the matrix is somewhat sensitive to the dissolution medium pH. This is possibly due to the effect of medium composition on the rate of matrix erosion. By increasing the content of the more slowly erodible HPMC, differences in release rate related to the dissolution medium could sometimes be reduced.
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