Acne vulgaris 1 Adapalene 1 Cationic charges 1 Cationics 1 Charge potentials Coulomb interactions 1 Drug delivery 1 Electrostatic emulsifier 1 Electrostatic interaction 1 Emulsification 1 Emulsion 1 Emulsions 1 Methoxypolyethylene glycol 1 Negative charge 1 Negatively charged 1 Therapeutic efficacy 1