A sustained-release oral dosage form containing only one pharmacologically active ingredient, comprising, a. therapeutically effective amount of the pharmacologically active ingredient having aqueous solubility of greater than 1 mg/ml to be delivered in a sustained release manner, b. 15 to 90% by weight of the total composition of at least one non-swelling pH dependent, release retardant selected from hydroxypropylmethylcellulose acetate succinate, hydroxypropylmethylcellulose phthalate, hydroxymethylethylcellulose phthalate, cellulose acetate phthalate, cellulose acetate succinate, cellulose acetate maleate, cellulose acetate trimelliate cellulose benzoate phthalate, cellulose propionate phthalate, methylcellulose phthalate, carboxymethylethylcellulose, ethylhydroxyethylcellulose phthalate, styrene acrylic acid copolymer, methyl acrylate acrylic acid copolymer, methyl acrylate methacrylic acid copolymer, butyl acrylate styrene acrylic acid copolymer, methacrylic acid methyl methacrylate copolymer, methacrylic acid ethyl acrylate copolymer, methyl acrylate methacrylic acid octyl acrylate copolymer, vinylacetate maleic acid anhydride copolymer, styrene maleic acid anhydride copolymer, styrene maleic acid monoester copolymer, vinylmethylether maleic acid anhydride copolymer, ethylene maleic acid anhydride copolymer, vinylbutylether maleic acid anhydride copolymer, acrylonitrile methyl acrylate maleic acid anhydride copolymer, butyl acrylate styrene maleic acid anhydride copolymer, polyvinyl alcohol phthalate, polyvinylacetal phthalate, polyvinyl butylate phthalate, polyvinylacetoacetal phthalate, methacrylic acid methylmethacrylate copolymer or methacrylic acid ethylacrylate copolymer, and c. 15 to 75 % by weight of the total composition of at least one non-swelling pH independent, release-retardant selected from polyvinyl alcohol, polyvinyl acetate, Kollidon SR (which is a mixture of 8 parts w/w of polyvinyl acetate and 2 parts w/w of polyvinylpyrrolidone), polymethacrylic acid derivatives, ethyl cellulose, triglycerides, waxes lipids, or fatty acids or their salts, wherein the dosage form provides: pH independent drug release for a considerable period of time after administration and absence of significant swelling of the dosage form, and wherein only non-swelling release retardants are used. a. therapeutically effective amount of the pharmacologically active ingredient having aqueous solubility of greater than 1 mg/ml to be delivered in a sustained release manner, b. 15 to 90% by weight of the total composition of at least one non-swelling pH dependent, release retardant selected from hydroxypropylmethylcellulose acetate succinate, hydroxypropylmethylcellulose phthalate, hydroxymethylethylcellulose phthalate, cellulose acetate phthalate, cellulose acetate succinate, cellulose acetate maleate, cellulose acetate trimelliate cellulose benzoate phthalate, cellulose propionate phthalate, methylcellulose phthalate, carboxymethylethylcellulose, ethylhydroxyethylcellulose phthalate, styrene acrylic acid copolymer, methyl acrylate acrylic acid copolymer, methyl acrylate methacrylic acid copolymer, butyl acrylate styrene acrylic acid copolymer, methacrylic acid methyl methacrylate copolymer, methacrylic acid ethyl acrylate copolymer, methyl acrylate methacrylic acid octyl acrylate copolymer, vinylacetate maleic acid anhydride copolymer, styrene maleic acid anhydride copolymer, styrene maleic acid monoester copolymer, vinylmethylether maleic acid anhydride copolymer, ethylene maleic acid anhydride copolymer, vinylbutylether maleic acid anhydride copolymer, acrylonitrile methyl acrylate maleic acid anhydride copolymer, butyl acrylate styrene maleic acid anhydride copolymer, polyvinyl alcohol phthalate, polyvinylacetal phthalate, polyvinyl butylate phthalate, polyvinylacetoacetal phthalate, methacrylic acid methylmethacrylate copolymer or methacrylic acid ethylacrylate copolymer, and c. 15 to 75 % by weight of the total composition of at least one non-swelling pH independent, release-retardant selected from polyvinyl alcohol, polyvinyl acetate, Kollidon SR (which is a mixture of 8 parts w/w of polyvinyl acetate and 2 parts w/w of polyvinylpyrrolidone), polymethacrylic acid derivatives, ethyl cellulose, triglycerides, waxes lipids, or fatty acids or their salts, wherein the dosage form provides: pH independent drug release for a considerable period of time after administration and absence of significant swelling of the dosage form, and wherein only non-swelling release retardants are used. pH independent drug release for a considerable period of time after administration and absence of significant swelling of the dosage form, and wherein only non-swelling release retardants are used.