A study was carried cut to increase dissolution rates of poorly soluble drugs: griseofulvin, prednisolone, and furosemide. Croscarmellose sodium (Ac-Di-SolR), as tablet disintegrant, was shown to markedly improve the dissolution rates of these hydrophobic and poorly soluble drugs both in wet granulation and dry granulation methods. The dissolution rates of poorly soluble drugs from tablets manufactured by wet granulation were found to be higher than those obtained from tablets manufactured by dry granulation. A relationship between drug dissolution and extent of Ac-Di-SolR was shown. For tablets containing Ac-Di-SolR, the hardness of tablets was shown to have no effect on the dissolution but significantly affected the disintegration. Comparative study of the effect of various disintegrants: Ac-Di-SolR, AvicelR PH 101, PolyplasdoneR XL, and ExplotabR on dissolution rates, Ac-Di-SolR showed to be the best tablet disintegrants. Whether incorporating AC-Di-SolR (as tablet disintegrants) into granules by intragranular, extragranular or 50 % intragranular plus 50% extragranular method, the dissolution rates of tablets were the same. Croscarmellose sodim (Ac-Di-SolR) was found to be excellent tablet disintegrant for poorly soluble drugs and could extensively increase dissolution rates of poorly soluble drugs, when used at the low concentration.