| 摘要 |
1330829 Immediate and sustained release layered bolus SMITH KLINE & FRENCH LABORATORIES 18 May 1972 [18 May 1971] 23426/72 Heading A5B A sustained release veterinary layered bolus comprising an immediate release layer and, contiguous therewith, a sustained release layer, the immediate release layer having a disintegration time in the rumen of less than 30 minutes and comprising sufficient of a medicament rapidly to provide a therapeutic level of the medicament in the blood of the ruminant animal to which the bolus is administered and the sustained release layer comprising a filler matrix of such a density that the bolus will lodge in the rumenoreticular sac of the ruminant animal and sufficient of the medicament that, at the rate of disintegration of the sustained release layer, a therapeutic level of the medicament is maintained in the blood of the ruminant animal to which the bolus is administered for at least 72 hours from the time of dosage, may be prepared by preparing separate immediate and sustained release granulations containing a medicament and a filler which at least in the sustained release granulation is of such a density that the bolus will lodge in the rumeno-reticular sac of the ruminant animal, placing the granulations in separate hoppers and selectively compressing the granulations into a layered bolus. The filler matrix may be iron powder, calcium sulphate dihydrate; Portland cement, plaster of Paris and/ or magnesium oxyiodide cement. The sustained release effect may be accomplished by employing a lubricant such as magnesium stearate, sodium stearate, calcium stearate, powdered stearic acid, talc, paraffin, cocoa butter, graphite and/or lycopodium. The medicament may be a sulphonamide derivative such as sulphamethazine or sulphathiazine; a tranquilizer such as chlorpromazine; an antibiotic such as chloramphenicol, tetracycline or penicillin; an anthelmintic such as piperazine phosphate, an anti-bloat agent such as organopolysilpxane; a hormone growth supplement such as stilbesterol, a vitamin or antibacterial such as furazolidone. |
