Patent ID: 8679540

Claim:
A liquid pharmaceutical formulation for the prolonged release of active principle (AP), wherein the formulation comprises: an aqueous colloidal suspension of low viscosity comprising micrometric particles based on partially ionized polymer (PO) and multivalent ions of opposite polarity to that of the polymer in a molar ratio r, wherein the micrometric particles have a size, measured in a test T, of between 1 and 70 μm; wherein the polymer is a water-soluble, biodegradable, amphiphilic copolymer carrying hydrophobic groups (GH) and ionizable hydrophilic groups (GI) that are at least partially ionized, wherein the polymer is a polyamino acid whose main chain is made up of aspartic residues or glutamic residues, at least some of these residues being modified by the grafting of at least one hydrophobic group (GH) in the chain or at the end of the chain, wherein the polymer spontaneously forms a colloidal suspension of nanoparticles in water, at pH=7.0, under isotonic conditions, wherein said nanoparticles are capable of associating spontaneously and non-covalently with at least one active principle, at pH 7.0, under isotonic conditions, wherein the multivalent ions have a valency less than or equal to 4, wherein said multivalent ions are added in an amount such that the ratio r, measured in a test M is between 0.3 and 10, and wherein the ratio r is defined by the formula r = n × [ IM ] [ GI ] , and wherein n is a valency of said multivalent ions, [IM] is a molar concentration of said multivalent ions, and [GI] is a molar concentration of said ionizable hydrophilic groups.