In situgel systems as ‘smart’ carriers for sustained ocular drug delivery

Hydrogels in ophthalmic applications

“…In most cases, the treatment involves the application of ophthalmic dosage forms 31 such as eye drops, suspensions or ointments. Unfortunately, some of the therapeutic approaches have 32 major shortcomings, especially in the treatment of the posterior segment of the eye, where many 33 vision-threatening diseases originate. Therefore, research focuses on the development of new materials 34 (e.g., for vitreous substitution) and more advanced drug delivery systems.…”

“…101 Hydrogels have already been approved for several ophthalmic 102 applications, with many more currently being under investigation. 103 For instance, they are successfully marketed as corrective soft con-104 tact lenses (SCL) [28], foldable intraocular lenses (IOL) [29,30], or 105 in situ gelling vehicles for ophthalmic drug delivery [31,32]. Most 106 research efforts currently aim at improving existing formulations 107 for antibiotics, anti-inflammatory drugs or b-blockers, or at devel-108 oping sustained release formulations for therapeutic proteins and 109 nucleic acids.…”

Corticosteroids and Anti-Complement Therapy in Retinal Diseases

“…Following in vitro and cell culture studies, both systems have been suggested to be promising for the treatment of intraocular neovascularization. Examples of in situ forming gels in the market include timolol maleate-loaded gellan gum-based product (Timoptic XE ® ) and another timolol maleate-containing formulation based on methyl cellulose, sodium citrate, and polyethylene glycol (Rysmon ® TG) (Agrawal et al 2012). …”

Eye

“…Hyaluronic acid possesses good adhesive properties. In situ-gelling systems, such as gellan gum, are used in order to increase the precorneal residence time of the eye drop and to obtain a sustained active substance release [78,79].…”