Drugs administered orally in solid dosage form should dissolve in gastrointestinal fluids before they are absorbed. Drugs with united solubility in aqueous media may exhibit dissolution rate limited absorption profile. Thus the rate of dissolution of the drugs in the gastrointestinal fluids could influence the rate and extent of absorption. In the case of poorly soluble drug the dissolution rate always influences its absorption. These solid dispersions provided sustained absorption of nifedipine in beagle dogs with good availability after oral administration. Stability studies indicated that these dispersions were stable for at least 6 months under accelerated conditions. Similar dispersions of dipyridamole also showed delayed absorption with good bioavailability.
