Improvement of dissolution of poorly soluble drugs by solid deposition on a super disintegrant .2. The choice of super disintegrants and effect of granulation

It is demonstrated that the dissolution from capsules and tablets of poorly soluble, hydrophobic drugs can be strongly improved by solid deposition of the drug upon hydrophilic, strongly swelling carriers like the super disintegrants sodium starch glycolate and croscarmellose sodium. As an effect of its lower swelling power, the super disintegrant crospovidone is far less effective than the other super disintegrants. Wet granulation of poorly soluble drugs with high concentrations of sodium starch glycolate resulted likewise in a strongly improved drug release and bioavailability from capsules and tablets. It was found, however, that granules containing a too high concentration of the super disintegrant slow down the drug release from tablets. This effect is caused by the formation of a viscous barrier of the super disintegrant in the granules during the dissolution process.