Delivery of drugs to the lower gi tract

Pharmaceutical compositions for orally delivering a therapeutically effective amount of a drug to the colon without significant release of the drug in the upper GI tract after oral administration of the composition are described. The composition is a unit dosage in the form of a tablet that comprises about 0.01% by weight to about 10% by weight of the drug that is useful in treating a colonic disorder or that is absorbed from the colon; about 40% by weight to about 98% by weight of a hydrocolloid gum obtainable from higher plants; and about 2% by weight to about 50% by weight of a pharmaceutically acceptable binder. The compositions are useful for treating lower GI disorders in human subjects by administering a suitable amount to a subject in need thereof. A particularly preferred aspect is the process for preparing such composition in the form of a tablet.