| 摘要 |
A dry, free flowing powder comprising one or more readily oxidizable biologically active substances is prepared by dissolving or dispersing in water the said active substance(s), at least one anti-oxidant, at least one gelable colloid and at least one carbohydrate, to obtain a liquid having a viscosity of between 500 and 1300 centipoise at 70 DEG C., atomizing the liquid from an atomizer nozzle, into air at a temperature of from 55 DEG to 90 DEG C., collecting the droplets solidifying to particles on a solid, substantially non-adherent collecting surface while effecting relative movement between the said surface and nozzle transverse to the movement of the impinging droplets and drying the particles. Specified active substances are Vitamins A, D2, D3 and E, albumins and antibiotics e.g. penicillin, bacitracin and tetracycline derivatives e.g. aureomycin. Details of the materials and construction of suitable collecting surfaces are given and the spraying is preferably carried out at the highest possible temperature. Drying may be performed subsequently to spraying e.g. in a drying drum.
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