Acta Pharm. 50 (2000) 157-162
The effects of primogel as disintegrant on the release of frusemide from encapsulated granules embedded in lubritab matrix were investigated. Primogel was used in concentrations of up to 10% (m/m) and granules were prepared by fusion method. Primogel caused the enhancement of frusemide release and changed the release of the drug from an unpredictable and erratic release to the first-order process. It is possible that primogel enhanced either dissolution or erosion mechanism, by compensating for the slow diffusion rate through the hydrophobic gel barriers of lubritab by creating greater wetting and porosity for the drug pathway. The mechanism of the drug release was anomalous (non-Fickian) diffusion as indicated by the release exponent which lies in the range of 0.45 to 0.89. The modification of the barrier properties of the lubritab by primogel was, therefore, largely dependent on the effect of the latter on wetting and porosity of the matrix.
Keywords: primogel, lubritab, barrier properties, dissolution profile, frusemide