A literature review.

Pharmacologic agents increasing urothelial permeability and useful for clinical purposes have been described, such as dimethylsulfoxide, protamine sulphate, chitosan, and nystatin. Among physical approaches, electromotive drug administration appears to be more effective than intravesical passive diffusion in delivering drugs through the urothelium into deeper layers of the bladder. Experimental and clinical reports demonstrated that electric current significantly increases the transport of local anaesthetics, mytomicin C, oxybutynin, resiniferatoxin, epinephrine, and dexamethasone. Among new chemical approaches, cell-penetrating peptides posses the ability to translocate macromolecular drugs across membranes of urothelial cells. The therapeutic benefits of sustained delivery afforded by thermosensitive hydrogel, which forms a depot for hydrophilic and hydrophobic drugs, have been demonstrated by delivering anti-inflammatory drugs. Liposomes improve the aqueous solubility of several hydrophobic drugs such as taxol, amphotericin, and capsaicin.

Electromotive drug administration, new in situ delivery systems, and bioadhesive liposomes may make it possible to extend intravesical therapy and drug administration to many bladder diseases. Research to expand knowledge of the chemical and physical properties of the bladder and processes regulating drug transport across biologic membranes is needed to make this a reality.

Antonella Giannantoni^a, Savino M. Di Stasi^b, Michael B. Chancellor^c, Elisabetta Costantini^a, Massimo Porena<sup>a

a</sup> Department of Urology, University of Perugia, Perugia, Italy
^b Department of Urology, “Tor Vergata” University of Rome, Rome, Italy
^c McGowan Institute of Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States

Accepted 16 August 2006 published online 30 August 2006.