The present invention relates to a product for injecting the formation of a solid implant into the body of a subject, said product comprising a base composition, which is pharmaceutically acceptable, which contains at least one solvent and at least one first soluble polysaccharide in said solvent, said base composition is capable of forming a precipitate in contact with an optionally saline aqueous solution. Typically, the product further comprises a given amount of at least one pharmaceutically acceptable active substance chosen from: bactericidal / antiseptic / antifungal agents which are soluble or soluble in said solvent, such as eosin and methylene blue and potassium iodide； antibiotics, growth factors, hydroxyapatite, hormones, anti-tumor agents, antimitotic agents, topoisomerase inhibitors, anti-cancer agents and mixtures of at least two of said active substances, in particular in powder form； and - contrast agents and especially radionuclides； said amount of active substance is mixed with said base composition or packaged separately from said base composition, the mixture formed by said base composition and said amount of active substance has a viscosity which allows the injection of said mixture and said mixture forms a precipitated on contact with an optionally saline aqueous solution. La présente invention concerne un produit permettant par injection la formation d'un implant solide dans le corps d'un sujet, ledit produit comprenant une composition de base, pharmaceuticalement acceptable, qui contient au moins un solvant et au moins un premier polysaccharide soluble dans ledit solvant, ladite composition de base est apte à former un précipité au contact d'une solution aqueuse éventuellement saline. De manière caractéristique, le produit comprend, en outre, une quantité donnée d'au moins une substance active, pharmaceuticalement acceptable, choisie parmi : - les agents bactéricides/antiseptiques/antifongiques ioniques et solubles
