Abstract: Use of .alpha.-hydroxy acids and poly-.alpha.-hydroxy acids as spacer between a therapeutically and/or diagnostically active compound and a soluble macromolecular carrier in pharmaceutical compositions having site-specific delivery. In one embodiment glycolic acid, L-lactic acid or tetra-L-lactic acid is used as spacer between a non-steroidal anti-inflammatory substance and a carrier of low molecular protein (LMWP).

Abstract: A sustained release suppository comprising in a usual suppository basea) a water-soluble therapeutically active substance, the average particle size of which is smaller than 20 .mu.m,b) a physiologically acceptable organic substance which is swellable in contact with water, andc) hydrophobic silicium dioxide.The suppository base is usually a fat having a melting range of from 29.degree. to 38.degree. C. As ingredient b) cellulose derivatives such as hydroxypropylmethylcellulose may be used, in a quantity of from 5 to 40% by weight, preferably 9 to 15% by weight. Ingredient c) is preferably used in a quantity of from 3 to 6% by weight. Also a process for manufacturing the suppositories is described.