Pharmaceutical multiple-units formulation

Claim 1

A pharmaceutical oral controlled release multiple-units formulation, comprising a multiplicity of individual units; (a) each unit comprising a cross-sectionally substantially homogeneous core coated, in an amount of from 2-25% of the total weight of the core, with an enteric coating which is substantially insoluble at a pH below 7 but soluble in the small intestine, the enteric coating comprising a material selected from the group consisting of acrylic polymers, shellac, cellulose acetate esters, polyvinyl acetate esters, hydroxypropylmethyl cellulose esters, alkyleneglycolether esters, N-butylacrylate-maleic anhydride copolymers, isobutylacrylate-maleic anhydride copolymers and ethylacrylate-maleic anhydride copolymers; and (b) each core being constituted of a multiplicity of particles having average sizes of about 1-10 μm, each of which particles contains: (i) a sparingly soluble active substance selected from the group consisting of indomethacin, spironolactone, ibuprofen, furosemide, sulfadiazine, sulfamerazine, progesterone, reserpine, pyrvinium embonate, mofebutazone, hydrochlorothiazide, tetracycline, tolbutamide, acetaminophen, testosterone, valporic acid, estradiol, acetazolamide, erythromycin, iron salts, hydralazine, carbamazepine, quinidine, and cardiac glycosides, in an amount of from 10-90% by weight of the particle; and (ii) a readily soluble, dispersion-enhancing substance, in an amount of up to 10% by weight of the active substance, for increasing exposure of the active substance to intestinal fluids, the dispersion-enhancing substance being an anionic surfactant selected from the group consisting of sodium salts of fatty alcohol sulfates, sulfosuccinates, partial fatty acid esters of sorbitans, and partial fatty acid esters of polyhydroxyethylene sorbitans and polyhydroxyethylene fatty alcohol ethers; the active substance and the dispersion-enhancing substance being co-comminuted with one another to form said particles, and the particles being admixed with a disintegration-enhancing substance comprising (1) a material which is readily soluble in intestinal fluids and is selected from the group consisting of saccharose, glucose, mannitol, sorbitol and lactose, (2) an insoluble material selected from the group consisting of talc, aluminum silicate, zinc oxide, titanium dioxide, colloidal silica and magnesium trisilicate, and (3) mixtures thereof, in an amount of at least 20% by weight of the particles.