The invention provides an ocular iontophoresis device for delivering medication, the device comprising a medication reservoir suitable for being positioned on the eye, at least one medication in solution in the reservoir, an active electrode disposed in the reservoir, and a passive electrode, the device including at least one medication dissolved in non-saline water, the said solution having a pH lying in the range 6.5 to 8.5, the medication having a pKa lying in the range about 5.5 to about 9.5 and includes an active principle which is associated with an additive, such as a dendrimer, a polymer, a nanoparticle, a microsphere, a liposome, or an emulsion, and having an ionic form of valency greater than or equal to 1.