G. Bettinetti et P. Mura, DISSOLUTION PROPERTIES OF NAPROXEN IN COMBINATIONS WITH POLYVINYLPYRROLIDONE, Drug development and industrial pharmacy, 20(8), 1994, pp. 1353-1366
The effect of the molecular weight of polyvinylpyrrolidone on the solu
bility and dissolution properties of naproxen using solid dispersions
(coevaporates and colyophilized products) and physical mixtures was in
vestigated. Factors such as method of drug incorporation with the poly
mer and polymer mass fraction influence the dissolution rate of naprox
en from both powders and constant surface area discs. The best results
were obtained with the colyophilized products at the drug-to-polymer
7:3 weight ratio, in the rank order (most effective to least) K15>K30>
K90 (dispersed amount) and K30>K90>K15 (rotating disc). The physical s
tate of naproxen, ie. amorphous or crystalline, in solid combinations
with polyvinylpyrrolidone was checked by means of X-ray powder diffrac
tion. Drug-polymer interactions in the liquid state were revealed with
solubility experiments. Drug-polymer interactions in solid state were
demonstrated by combining the X-ray diffraction data with the results
of thermal analysis (DSC, TGA) and microscopic observation.