A water insoluble composition solid in appearance at a temperature of less than or equal to 20°C comprising for 100% of the mass of same: X1% by mass of at least one lipophilic surfactant having a value HLB H1 greater than or equal to 1 and less than 10 X2% by mass of at least one hydrophilic surfactant having a value HLB H2 greater than or equal to 10 and less than or equal to 20 characterised by the fact that the HLB of same = X1.H1 + X2.H2 X1 and X2 varying from 2 to 60 and characterised in that it is free of acrylic polymer and/or of acetate succinate.
