Controlled release formulations

An oral controlled release formulation, comprising

• a plurality of substrates comprising a portion of an effective dose of methylphenidate or a pharmaceutically acceptable salt thereof in immediate release form,
• a hydrophobic material comprising an acrylic polymer coated onto the surface of said substrates in an amount sufficient to retard the release of said portion of the methylphenidate or a pharmaceutically acceptable salt thereof,
• an enteric coating applied over said hydrophobic coating to obtain enteric coated substrates, wherein said enteric coating is in an amount sufficient to substantially delay the release of said methylphenidate or a pharmaceutically acceptable salt thereof from said substrates until after said formulation passes through the stomach, wherein said enteric coating is derived from an aqueous dispersion comprising an acrylic/methacrylic copolymer, a plasticizer and a glidant,
• the formulation further comprising the remaining portion of the effective dose of the methylphenidate or pharmaceutically acceptable salt thereof in immediate release form, and
• wherein the formulation provides a maximum plasma concentration of methylphenidate at about 0.5 to about 2 hours after oral administration,
• and the duration of effect provided by the methylphenidate or pharmaceutically acceptable salt thereof contained in the formulation falls below effective plasma concentrations at about 10 to about 12 hours after the oral administration.

An oral controlled release formulation, comprising

• a plurality of substrates comprising a portion of an effective dose of methylphenidate or a pharmaceutically acceptable salt thereof,
• a controlled release coating comprising an acrylic polymer coated onto the surface of said substrates,
• an enteric coating applied over said controlled release coating to obtain enteric coated substrates, wherein said enteric coating is derived from an aqueous dispersion comprising an acrylic/methacrylic copolymer, a plasticizer and a glidant, and is in an amount sufficient to delay the release of said portion of the effective dose of the methylphenidate or pharmaceutically acceptable salt thereof from said enteric coated substrates until after said formulation passes through the stomach,
• the formulation further comprising the remaining portion of the effective dose in an immediate release form, and
• providing a time to maximum plasma concentration of methylphenidate at about 0.5 to about 2 hours after oral administration, and a duration of effect for a time period of from about 10 to about 12 hours.