The present invention is directed to a sustained release pharmaceutical
composition in oral dosage form consisting essentially of a
pharmaceutically effective amount of a medicament and a hydrophobic
material in the absence of a lactose or hydrophobic carbohydrate polymer,
said medicament being present in an amount greater than about 25% of the
pharmaceutical composition and having a water solubility greater than
about 1 gram per 10 mL of water at 25.degree. C., said hydrophobic
material having a melting point ranging from at least about 40.degree. C.
to about 100.degree. C. at 1 atm pressure, and being present in an amount
ranging from about 3% to about 20% by weight of the pharmaceutical
composition and in an amount less than the of the medicament, and said
hydrophobic material not being present in coating of said pharmaceutical
composition; said pharmaceutical composition being prepared by direct
compression in the absence of or melting the hydrophobic material or the
use of high shear mixer. The present invention is also directed to a
method of preparing said pharmaceutical composition.