ABSTRACT
Contact lenses have good biocompatibility and long wearing duration, and can be used as promising ocular drug delivery system. Drug loading contact lenses can retain the drug on the surface of eye and thus improve the bioavailability. In this review, we summarized the advantage of contact lenses as ocular drug delivery system, mechanism of improving drug absorption, drug loading method and release behavior, and influence of drug loading on physical properties of contact lenses.
ABSTRACT
In situ gel is liquid upon instillation and undergo phase transition under physiological conditions to form visco-elastic gel with dual advantages of liquid and gel. Ordinary eye drops exist a problem of short residence time with low bioavailability. In recent years, an impressive number of novel in situ gel systems have been reported for ocular drug delivery to increase bioavailability with the extension of corneal residence time. In this article, the classification and application about in situ gel for ocular drug delivery are reviewed, then the study status and the key technical problem of the in situ ophthalmic gel in detail are described. In addition, the future advancement of this field is also discussed.