Eye is most unique organ of the body. In the development of ophthalmic products, drug delivery is one of the most challenging and difficult fields for investigators. The usual ophthalmic dosage forms are account for 90% of currently accessible ophthalmic formulations. Various drug delivery systems are used to deliver drug into eyes are used but there are various limitations of conventional systems so researchers are finding new ways by which contact time, bioavailability and residence time can be enhanced as well as patient discomfort and frequency of dose can be reduced To improve ophthalmic drug bioavailability, there are considerable efforts directed towards newer drug delivery systems for ophthalmic administration. Newer research in ophthalmic drug delivery systems is directed towards a 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, but which at the same time slow down the removal of the drug. The conventional formulations such as solutions, suspensions, ointments, etc. shows some constraints such as increased precorneal elimination, high variability in efficiency and blurred vision, respectively, which reduce their bioavailability. In situ activated gel forming systems are liquid upon instillation and undergo phase transition in the ocular cul-de-sac to form a viscoelastic gel in response to environmental changes such as change in temperature, pH, ion concentration and osmolarity. In the past few years, an impressive number of novel temperature, pH, and ion induced in situ gel-forming systems have been reported for sustain ophthalmic drug delivery.
Loading....