On the employment of λ-carrageenan in a matrix system. I. Sensitivity to dissolution medium and comparison with Na carboxymethylcellulose and xanthan gum

摘要: Abstract Three anionic polysaccharidic materials, characterized by their differing sensitivity to pH, especially at low values, were compared in order assess behaviour on the performance matrix systems. λ-Carrageenan, a sulphated polymer, was with two carboxylic polymers, Na carboxymethylcelluse (Na CMC) and xanthan gum. In case of CMC both gelation rate ionic charge are affected gastric pH. Gelation properties gum described as being more or less insensitive The acidic λ-carrageenan, however, expected maintain capability ionization even pH values. Erosion distilled water buffers 1.2 6.8 evaluated. Matrices containing model drug either salbutamol sulphate diprophylline prepared tested for release same three media. λ-Carrageenan shows characteristic behaviour. Its control initial release, ascribed drug-polymer interactions, appears be remarkably effective independent characteristics dissolution medium.