Novel Ocular Drug Delivery Methods

Due to the unique anatomical and physiological factors of the eye, ocular drug delivery faces various challenges. Most ophthalmic drug formulations are administered as eye drops. However, because of barriers such as the various layers of ocular tissue and quick tear turnover, topical eye drops have low penetration and short drug contact times, which produces low bioavailability. Numerous innovative drug delivery systems have been explored to address the drawbacks of topical ophthalmic formulations, with the goal of easy administration, increased biocompatibility, while retaining minimal interference with vision. In this book chapter, hydrogel including in situ hydrogel, contact lenses, collagen shields, and nanoparticle systems including liposomes, dendrimers, and polymeric nanoparticles will be reviewed. Ciprofloxacin is used as a case to compare the advantages and limitations of various systems. Combining nanocarriers and hydrogel systems showed longer drug contact time and higher bioavailability compared to drug delivery with either nanocarrier or hydrogel alone, which represents a promising direction for further investigation.