Modified release pharmaceutical compositions comprising mycophenolate as the active agent or its pharmaceutically acceptable salts, esters, polymorphs, isomers, prodrugs, solvates, hydrates, or derivatives thereof, wherein the said composition exhibits a biphasic release profile when subjected to in-vitro dissolution and/or upon administration in-vivo are provided. The composition provides a drug release in a manner such that the drug levels are maintained above the therapeutically effective concentration (EC) constantly for an extended duration of time. Further, the difference between the maximum plasma concentration of the drug (Cmax) and the minimum plasma concentration of the drug (Cmjn), and in turn the flux defined as ((Cmax&minus；Cmjn)/Cavg) is minimal. The present invention also provides process of preparing such dosage form compositions and prophylactic and/or therapeutic methods of using such compositions.
