Method for preparing preparations having controlled release of an active component

A process for producing a preparation comprising a plurality of granules, each granule having a core and a unitary layer thereon containing at least one pharmaceutically active material which, on disintegration, release said pharmaceutically active material at a controlled rate, comprising applying to said cores in a continuous coating operation a solution or suspension containing at least one pharmaceutically active compound and at least one pharmaceutically inactive release controlling substance selected from the group consisting of waxes, fatty acids, fatty acid esters, fatty alcohols, polyethylene glycols, polyvinylpyrrolidones, polyvinylacetates, polyacrylates, polymethacrylates, cellulose derivatives, talcum and silicic acid, over a period of time sufficient to cause said unitary layer of said active ingredient and inactive release controlling substance to form on each core to give granules of size 0.3-2 mm, during said time period the concentration of active ingredient being decreased in the solution or suspension from which the layer is formed by adding additional release controlling substance to the solution or suspension, whereby there results granules each having a layer containing an active ingredient in which layer the concentration of active ingredient decreases radially outwardly from the core to the outer surface of said layer.

A process for producing a preparation comprising a plurality of granules each having a core and a unitary layer thereon containing at least one biologically active material which, on disintegration, release said biologically active material at a controlled rate, comprising applying to said cores in a continuous coating operation a solution or suspension containing at least one active compound and at least one biologically inactive release controlling substance over a period of time sufficient to cause said unitary layer of said active ingredient and inactive release controlling substance to form on each core to give granules of size 0.3-2 mm, during said time period the concentration of active ingredient being decreased in the solution or suspension from which the layer is formed by adding additional release controlling substance to the solution or suspension, whereby there results granules each having a layer containing an active ingredient in which layer the concentration of active ingredient decreases radially outwardly from the core to the outer surface of said layer.

A process for producing a preparation comprising a plurality of granules, each granule having a core and a unitary layer thereon containing at least one biologically active material which, on disintegration, release said biologically active material at a controlled rate, comprising applying to said cores in a continuous coating operation a solution or suspension containing at least one active compound and at least one biologically inactive release-controlling substance selected from the group consisting of waxes, fatty acids, fatty acid esters, fatty alcohols, polyethylene glycols, polyvinylpyrrolidones, polyvinylacetates, polyacrylates, polymethacrylates, cellulose derivatives, talcum and silicic acid, over a period of time sufficient to cause said unitary layer of said active ingredient and inactive release controlling substance to form on each core to give granules of size 0.3-2 mm, during said time period the concentration of active ingredient being decreased in the solution or suspension from which the layer is formed by adding additional release controlling substance or suspension, whereby there results granules each having the concentration of active ingredient decreases radially outwardly from the core to the outer surface of said layer.