APPLICATIONS OF THE ION-PAIR CONCEPT TO HYDROPHILIC SUBSTANCES WITH SPECIAL EMPHASIS ON PEPTIDES

Previous investigations have shown that ionic drugs with high aqueous solubilities can be lipophilized by ion-pair formation, with appropria te counter-ions. This type of association may prove promising for seve ral biopharmaceutical, analytical and technological applications. This review examines the ion-pair concept with special emphasis on its app lication to peptides. The conditions for ion-pair formation of differe nt molecules, as well as their transfer to organic solvents, are descr ibed. The use of ion-pairs to increase the permeation of various thera peutic agents, including peptidic drugs, is also discussed. Recent in micro- and nanoencapsulation of peptides are also commented upon.