IN SITU HYDROGEL: DIFFERENT APPROACHES TO OCULAR DRUG DELIVERY

Ophthalmic drug delivery is one of the more interesting and challenging endeavor facing the pharmaceutical scientist. The conventional ophthalmic drug delivery systems like solution, suspensions and ointment’s show drawbacks such as increased pre-corneal elimination, high variability in efficiency and blurred vision respectively. To overcome these drawbacks there are considerable efforts directed towards newer drug delivery system for ophthalmic administration. Newer research in ophthalmic drug delivery system is directed towards amalgamation of several drug delivery technologies, that includes to build up systems which is not only extend the contact time of the vehicle at the ocular surface, increase corneal absorption of drug, but at the same time slow down the removal of the drug.. In situ forming ophthalmic hydro-gels are liquid upon instillation undergoes phase transition in the ocular cul-de-sac to form visco elastic gel and this provides a response to environmental changes. The factors considered during the formulation of in situ Hydrogel like temperature modulation, pH change, and presence of ion. The choice of a particular in situ Hydrogel depends on its intrinsic properties and envisaged therapeutic use. In situ forming ophthalmic gelling system provides ease of administration and reduces frequency of administration, improve patient compliance and comfort.