A solid oral pharmaceutical formulation for once-a-day administration of oxcarbazepine comprising a homogeneous matrix comprising: (a) oxcarbazepine; (b) 1-50%, by weight of the formulation, a matrix-forming polymer selected from the group consisting of cellulosic polymers, alginates, gums, cross-linked polyacrylic acid, carageenan, polyvinyl pyrrolidone, polyethylene oxides, and polyvinyl alcohol; (c) 1-80%, by weight of the formulation, at least one agent that enhances the solubility of oxcarbazepine selected from the group consisting of surface active agents, complexing agents, cyclodextrins, pH modifying agents, and hydration promoting agents; (d) 10-90%, by weight of the formulation, at least one release promoting agent comprising a polymer having pH-dependent solubility selected from the group consisting of cellulose acetate phthalate, cellulose acetate succinate, methylcellulose phthalate, ethylhydroxycellulose phthalate, polyvinylacetate phthalate, polyvinylbutyrate acetate, vinyl acetate-maleic anhydride copolymer, styrene-maleic mono-ester copolymer, Eudagrit L100-55 (Methacrylic Acid—Ethyl Acrylate Copolymer (1:1)), and methyl acrylate-methacrylic acid copolymers, wherein, in vitro: (i) between 20 and 74% of the total oxcarbazepine is released by 2 hours; and (ii) between 44 and 96% of the total oxcarbazepine is released by 4 hours. view more

The pharmaceutical formulation of claim 1, wherein the amount of oxcarbazepine is effective to produce a steady state blood level of monohydroxy derivative of oxcarbazepine in the range of about 2 μg/ml to about 10 μg/ml.

The pharmaceutical formulation of claim 1, wherein the formulation is effective in minimizing fluctuations between C<sub>min </sub>and C<sub>max </sub>of monohydroxy derivative of oxcarbazepine.

The pharmaceutical formulation of claim 8, which provides C<sub>max </sub>levels of monohydroxy derivative of oxcarbazepine in the range of about 6 μg/ml to about 10 μg/ml and C<sub>min </sub>levels of monohydroxy derivative of oxcarbazepine in the to about 5 μg/ml. view more

The formulation of claim 11 in the form of tablets.

The pharmaceutical formulation of claim 1, wherein the polymer having pH-dependent solubility dissolves at pH values of more than 5.

The pharmaceutical formulation of claim 1, wherein the polymer having pH-dependent solubility dissolves at pH values of more than 6.