Composition of biocompatible microparticles of alginic acid for the controlled release of active ingredients by intravenous administration. The invention relates to a biocompatible composition which comprises microparticles of alginic acid or its salts and an active ingredient. More particularly, the invention relates to microparticles for the encapsulation of an active ingredient to be administered intravenously to a patient who needs it. These microparticles are of a combination of size sufficient to increase the half-life or survival of the active ingredient in blood, with a low uptake in the liver and a fast cell clearance when administered intravenously.
