The Preparation and Stability of Fast Release Furosemide – PVP Solid Dispersion

Abstract
Furosemide-PVP solid dispersion systems were prepared by co-evaporation and freeze-drying methods. The X-ray diffraction patterns indicated that furosemide in the coprecipitates was in amorphous form. The dissolution rate of furosemide was markedly increased in these solid dispersion systems. The increase in dissolution was a function of the ratio of drug to PVP used. With 1:7 ratio the best result was obtained. The 49000 mol. wt. PVP yielded the most rapid furosemide dissolution. Dissolution studies have shown that coprecipitate of furosemide-PVP (1:7) is the best combination. Factors contributing to the enhancement of furosemide' dissolution from the dispersion in PVP were discussed. The increase in release rates was attributed to the increased wettability, coacervate formation and the complexation. The effect of aging on furosemide-PVP solid dispersions has been investigated. After storage, under the different humidities (55%, 70% and 85% RH) coprecipitates showed no change in either dissolution rate or X-ray diffraction patterns.