A pharmaceutical composition comprising TPR (timed pulsatile release) beads, wherein said TPR beads comprise: a solid dispersion of at least one active pharmaceutical ingredient in at least one solubility-enhancing polymer; and a TPR coating comprising a water insoluble polymer and an enteric polymer; wherein the active pharmaceutical ingredient comprises a weakly basic active pharmaceutical ingredient having a solubility of not more than 100 μg/mL at pH 6.8; wherein the solid dispersion of the active pharmaceutical ingredient and solubility enhancing polymer is deposited on an inert core; wherein the TPR beads comprise IR (immediate release) beads coated with the TPR coating; and the IR beads comprise inert cores coated with the solid dispersion; wherein the solubility-enhancing polymer is selected from the group consisting of polyvinylpyrrolidone, vinyl acetate/vinyl pyrrolidone copolymers, methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, polyethylene oxide, polyethylene glycol, and cyclodextrins; wherein the water-insoluble polymer is selected from the group consisting of polymers or copolymers of methacrylic acid esters having quaternary ammonium groups, polyvinyl acetate polymers or copolymers, cellulose acetate, cellulose acetate butyrate, ethyl cellulose, and mixtures thereof; wherein the enteric polymer is selected from the group consisting of acid substituted cellulose esters, polyvinyl acetate phthalate, pH-sensitive methacrylic acid- methylmethacrylate copolymers and shellac; and wherein the pharmaceutical composition provides a therapeutically effective level of the active pharmaceutical ingredient over a 12-18 hour period when dissolution tested in vitro using US Pharmacopeia Apparatus 1, baskets @ 100 rpm, or Apparatus 2, paddles @ 50 rpm, and a two-stage dissolution methodology, testing in 700 mL of 0.1 N HCl for the first two hours and thereafter in 900 mL at pH 6.8 obtained by adding 200 mL of a pH modifier. a solid dispersion of at least one active pharmaceutical ingredient in at least one solubility-enhancing polymer; and a TPR coating comprising a water insoluble polymer and an enteric polymer; wherein the active pharmaceutical ingredient comprises a weakly basic active pharmaceutical ingredient having a solubility of not more than 100 μg/mL at pH 6.8; wherein the solid dispersion of the active pharmaceutical ingredient and solubility enhancing polymer is deposited on an inert core; wherein the TPR beads comprise IR (immediate release) beads coated with the TPR coating; and the IR beads comprise inert cores coated with the solid dispersion; wherein the solubility-enhancing polymer is selected from the group consisting of polyvinylpyrrolidone, vinyl acetate/vinyl pyrrolidone copolymers, methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, polyethylene oxide, polyethylene glycol, and cyclodextrins; wherein the water-insoluble polymer is selected from the group consisting of polymers or copolymers of methacrylic acid esters having quaternary ammonium groups, polyvinyl acetate polymers or copolymers, cellulose acetate, cellulose acetate butyrate, ethyl cellulose, and mixtures thereof; wherein the enteric polymer is selected from the group consisting of acid substituted cellulose esters, polyvinyl acetate phthalate, pH-sensitive methacrylic acid- methylmethacrylate copolymers and shellac; and wherein the pharmaceutical composition provides a therapeutically effective level of the active pharmaceutical ingredient over a 12-18 hour period when dissolution tested in vitro using US Pharmacopeia Apparatus 1, baskets @ 100 rpm, or Apparatus 2, paddles @ 50 rpm, and a two-stage dissolution methodology, testing in 700 mL of 0.1 N HCl for the first two hours and thereafter in 900 mL at pH 6.8 obtained by adding 200 mL of a pH modifier.