Abstract: A colloidal solution of human serum albumin is prepared by mixing an aqueous solution of the latter with a non-ionic surface-active agent and an acid solution of a tin(II) salt, adjusting the pH to 3.5 to 8.0 and heating at a constant temperature between 45.degree. and 100.degree. C. until complete hydrolysis of the tin(II) salt and denaturation of the albumin have taken place; the colloidal solution can also be lyophilized. By treating the solution or the lyophilizate with a .sup.99m Tc-pertechnetate solution, a colloidal preparation is obtained for scintigraphy of the reticuloendothelial system or the lymphatic system. By suitable pH adjustment, the process makes it possible selectively to obtain colloids with a particle size of, for example, 3.0-0.2 or 0.2-0.03 or below 0.03 .mu.m.

Abstract: Multi-zone pharmaceutical tablets are produced by compressing the contents of a tablet mold. The contents include a granular chewing gum mass and a non-plastic tablet mass, or a chewing gum insert in the recess of a multi-layer non-plastic tablet mass. At least one zone of the tablet, preferably the chewing gum mass, contains a pharmaceutically active ingredient.