Process for the preparation of a composition comprising an oil phase, an aqueous phase, at least one emulsifying system of water-in-oil (W/O) type, optionally at least one emulsifying system of 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 the said polyelectrolyte is a copolymer of 2-acrylamido-2-methylpropanesulfonic acid partially or totally salified with acrylamide and optionally one or more monomers chosen from monomers containing a partially or totally salified weak acid function and/or from neutral monomers other than acrylamide, said production process being characterized in that the preparation of said aqueous phase comprises the dissolution in the aqueous medium of solid 2-acrylamido- 2-methyl propanesulfonic acid before neutralization. Cosmetic, dermopharmaceutical or pharmaceutical composition comprising the inverse latex directly obtained by said process.