The present invention relates to novel pharmaceutical formulations based on stable and fluid aqueous colloidal suspensions for the sustained release of active principle (s), in particular protein (s), as well as the applications, particularly therapeutic applications, of these formulations. The object of the invention is to provide a fluid pharmaceutical formulation for the sustained release of active principle (s), allowing after parenteral injection to significantly increase the in vivo release time of a therapeutic protein while decreasing, the peak of plasma concentration of the active protein, and which is otherwise stable to the conservation and moreover biocompatible, biodegradable non-toxic, non-immunogenic and well tolerated locally. The formulation according to the invention is an aqueous colloidal suspension of low viscosity, submicron particles of biodegradable PO polymer, water-soluble and bearing hydrophobic groups (GH), which particles are non-covalently associated with at least one active ingredient (AP) and forming a gelled deposit at the injection site, this gelation being caused by a protein present in the physiological medium.La présente invention concerne de nouvelles formulations pharmaceutiques àbase de suspensions colloïdales aqueuses stables et fluides pour la libérationprolongée de principe(s) actif(s), en particulier protéinique(s), ainsi queles applications, notamment thérapeutiques, de ces formulations. Le but del'invention est de proposer une formulation pharmaceutique fluide pour lalibération prolongée de principe(s) actif(s), permettant après injection parvoie parentérale d'accroître significativement la durée de libération in vivod'une protéine thérapeutique tout en diminuant, le pic de concentrationplasmatique de la protéine active, et qui soit par ailleurs stable à laconservation et de surcroît biocompatible, biodégradable non-toxique, non-immunogène et bien tolérée localement. La formulation selon l'inven
