To obtain a medicine compsn. which contains a specific alginic acid partial ester (salt), can carry a pharmaceutically active substance as an alcohol component, is excellent in capability for carrying a basic substance exhibiting pharmaceutical activity, and is useful for alkaloids, anticonvulsants, antibiotics, or the like.

The medicine compsn. contains (A) an alginic acid partial ester (salt) obtd. by esterifying 5-90% of the carboxyl group of alginic acid with (A1) a 1-34C aliph. alcohol, (A2) an araliph. alcohol having a 1-4C aliph. chain and a benzene ring, (A3) an up to 34C mono- or polycyclic aliph. - cycloaliph. or cycloaliph. alcohol, or (A4) a heterocyclic alcohol having O, S, or N as the heteroatom and optionally (B) a pharmaceutically active substance and (C) a pharmaceutically acceptable vehicle.