Ion Pairs for Transdermal and Dermal Drug Delivery: A Review

Ion pairing is a strategy used to increase the permeation of topically applied ionised drugs. Formation occurs when electrostatic energy attraction between oppositely charged ions exceeds their mean thermal energy, making it possible for them draw together and attain critical distance. These then behave as neutral species, allowing partition more readily into lipid environment. Partition coefficient studies may be determine potential pair an organic phase but cannot relied upon predict flux. Early researchers indicated that temperature, size dielectric constant solvent system all contributed formation ion pairs. While important, this outweighed by improved lipophilicity counter due increased length carbon chain. Organic are effective than inorganic moieties in forming In addition being permeation, pairs have been control even prevent active ingredient. They also stabilise solid nanoparticle formulations. conjunction with enhancers, enhancers pairing. This review attempts show various ways which drug delivery via skin. It endeavours extract consolidate common approaches order inform future formulations topical transdermal delivery.