GB618542A - Improvements in methods of making tablets - Google Patents

Abstract

Tablets, particularly medicinal tablets, having edges and a straight side are tumbled, e.g. in a tumbling barrel or like rotating vessel, until they nave acquired shapes approximating ellipsoids. After removing the abrasion dust, the ellipsoids may be coated with the desired solution or composition, the resulting coating being continuous and of uniform thickness. If the final protective coating is to be applied as a hot aqueous solution of a colloid such as gelatine, the ellipsoids may be first given a thin undercoating of an edible resin such as shellac. The method may be applied to tablets formed of a granulation containing a plurality of vitamins and minerals and wherein the incompatible ingredients are isolated from each other by being incorporated in different beadlets having matrices of a gelable colloid. In an example, vitamin A concentrate (fish liver oil) is emulsified with a hot aqueous solution of gelatine and corn syrup, the emulsion being solidified into sheets or beadlets by cooling, and the sheets if formed being ground to powder, iron ammonium citrate is dissolved in an aqueous solution of corn syrup, gelatin being subsequently added with heating, and the resulting solution being formed into beadlets; a dry granulation powder of vitamin C is also prepared; the three granular preparations are homogeneously mixed, the mixture being compressed into tablets and the tablets being tumbled and coated as previously described. Thiamine chloride (vitamin B), riboflavin (vitamin G), niacinamide, and viosterol (vitamin D) may be present in the vitamin A granules. Calcium pyrophosphate may also be added to the preparation. Agar, pectin, or methyl cellulose may be used to form the matrices of the beadlets.