Process for the preparation of a composition comprising an oil phase, an aqueous phase, at least one emulsifying system of the water-in-oil (W/O) type, optionally at least one emulsifying system of the oil-in-water (O/W) type, in the form of an inverse latex comprising from 20% to 70% by weight and preferably from 25% to 50% by weight of a branched or crosslinked polyelectrolyte, characterized in that said polyelectrolyte is a copolymer of 2-acrylamido-2-methylpropanesulfonic acid partially or totally salified in the form of a sodium salt, or of a potassium salt or of an ammonium salt, with acrylamide and optionally one or more monomers chosen from monomers containing a weak acid function partially or totally salified in the form of a sodium salt, of a potassium salt or of an ammonium salt, and/or from neutral monomers other than acrylamide, said preparation process comprising the following steps: A Step a) of preparation of an aqueous phase comprising acrylamide 2-acrylamido-2-methylpropanesulfonic acid partially or totally salified in the form of a sodium salt, or of a potassium salt or of an ammonium salt, optionally one or more monomers chosen from monomers containing a weak acid function partially or totally salified in the form of a sodium salt, of a potassium salt or of an ammonium salt, and/or from neutral monomers other than acrylamide and the possible other hydrophilic additives, said preparation consisting in placing free 2-acrylamido-2-methylpropanesulfonic acid, optionally 2-acrylamido-2-methylpropanesulfonic acid in the form of a sodium salt, of a potassium salt or of an ammonium salt, acrylamide, said optional hydrophilic additives and, if necessary, an alkaline agent chosen from sodium hydroxide, potassium hydroxide or aqueous ammonia in water, such that the pH of the solution remains greater than 1 and less than 5, to obtain a first aqueous mixture A1 having a pH greater than to 1 and less than 5; and in adjusting the pH of said the first aqueous mixture A1 to a pH between 5 and 6.5, to obtain said aqueous phase; A step b) of emulsification of said aqueous phase, in an organic phase containing a surfactant system of the water-in-oil (W/O) type, the oil intended to be present in the final composition, optionally a volatile oil, and optional hydrophobic additives, to form a water-in-oil emulsion; A step c) of polymerization of the monomers in said water-in-oil emulsion, said reaction being initiated by introducing a free-radical initiator into said emulsion, to form an inverse latex of said copolymer; Optionally a step d), wherein said inverse latex of said copolymer, is concentrated by distillation until the said volatile oil has been removed, to form an inverse latex of said copolymer; and A ste e) wherein an emulsifying system of the oil-in-water (O/W) type is introduced, if desired, at a temperature below 50°C, in said inverse latex of said copolymer, or optionally in said inverse latex of said copolymer, to form a self-invertible inverse latex of said copolymer. A Step a) of preparation of an aqueous phase comprising acrylamide 2-acrylamido-2-methylpropanesulfonic acid partially or totally salified in the form of a sodium salt, or of a potassium salt or of an ammonium salt, optionally one or more monomers chosen from monomers containing a weak acid function partially or totally salified in the form of a sodium salt, of a potassium salt or of an ammonium salt, and/or from neutral monomers other than acrylamide and the possible other hydrophilic additives, said preparation consisting in placing free 2-acrylamido-2-methylpropanesulfonic acid, optionally 2-acrylamido-2-methylpropanesulfonic acid in the form of a sodium salt, of a potassium salt or of an ammonium salt, acrylamide, said optional hydrophilic additives and, if necessary, an alkaline agent chosen from sodium hydroxide, potassium hydroxide or aqueous ammonia in water, such that the pH of the solution remains greater than 1 and less than 5, to obtain a first aqueous mixture A1 having a pH greater than to 1 and less than 5; and in adjusting the pH of said the first aqueous mixture A1 to a pH between 5 and 6.5, to obtain said aqueous phase; A step b) of emulsification of said aqueous phase, in an organic phase containing a surfactant system of the water-in-oil (W/O) type, the oil intended to be present in the final composition, optionally a volatile oil, and optional hydrophobic additives, to form a water-in-oil emulsion; A step c) of polymerization of the monomers in said water-in-oil emulsion, said reaction being initiated by introducing a free-radical initiator into said emulsion, to form an inverse latex of said copolymer; Optionally a step d), wherein said inverse latex of said copolymer, is concentrated by distillation until the said volatile oil has been removed, to form an inverse latex of said copolymer; and A ste e) wherein an emulsifying system of the oil-in-water (O/W) type is introduced, if desired, at a temperature below 50°C, in said inverse latex of said copolymer, or optionally in said inverse latex of said copolymer, to form a self-invertible inverse latex of said copolymer.