Proceeding for the preparation of the prolonged action granule compound containing 4-nitro-2-phenoxymethanesulfonanilide

A method for preparing a compound of granules of prolonged action containing 4-nitro-2-phenoxymethanesulfonanilide as active agent characterized by the following steps:

• i) mixing the active agent of fast action granules with a disintegrant;
• ii) micronizing the active agent together with a disintegrant;
• iii) rotating the micronized active agent disintegrant mix in a pan containing neutral granules simultaneously with the atomization of a solution of bonding polymers selected from a solution consisting of jellies of polyvinylpyrrolidine, polyethylene glycols or mixtures thereof to form granules of intermediate or conventional action;
• iv) separating the granules into two portions by weight with the one portion having the lower weight of the intermediate or conventional action granules and being removed from the pan with only the coating of the solution of the bonding polymers;
• v) atomizing coating polymers from a solution consisting of cellulose, acrylic polymers, shellac or combination thereof, and a plasticizer over one other of the two portions, having the greater weight and remaining in the pan, to form granules of controlled and prolonged action of the active principle having a granule size between 0.6 mm to 2.0 mm;
• and
• vi) associating or mixing the immediate or conventional action granules with the granules of controlled and prolonged action polymers to allow the preparation of a compound of sustained and prolonged liberation for administration of different doses of the active agent.