Harendra Prasad*1 and Navneet Kumar Verma2
1Chhatrapati Shahuji Maharaj Group of Institution Faculty of B.Pharmacy, Allahabad U.P., India
2Rameshwaram Institute of Technology and Management Lucknow, U.P, India
Received: 14 June 2014, Accepted: 19 July 2014, Published Online: 10 August 2014
Conventional eye drops shows relatively low bioavailability due to poor precorneal contact time. In situ hydrogel are of great importance in providing sustained ocular drug delivery due to their elastic properties hydrogel resist occular drainage leading to longer contact times. Sustained and Prolonged drug delivery approaches are very common in today. Formulation design and research work is still going on in achieving better drug product. Ophthalmic use of viscosity-enhancing agents, penetration enhancers and ocular inserts and ready existing drug carrier systems along with their application to ophthalmic drug delivery are very common to improve ocular bioavailability. Amongst these hydrogel systems are of very important. They help to increase in precorneal residence time of drug to a sufficient extent that an occular delivered drug can exhibit its maximum biological action. The concept of this innovative ophthalmic delivery approach to decrease the systemic side effects and create a more pronounced effect with lower doses of the drug. Many polymers are very useful with majority of hydrogel, which undergo reversible sol-gel phase transitions in the ocular cul-de-sac to form viscoelastic gels due to phase changes of polymers in response to the physiological environment and presence of ions in organism fluids. These in situ forming gels can be applied as solution and exhibit pseudo plastic behavior to minimize interference, increase pre corneal residence of the delivery system and enhanced ocular bioavailability. Now days in situ gels have been used as vehicles for the delivery of drugs for both local treatment and systemic effects.
Keywords: Bioavailability, Hydrogel, Precorneal, Insitugel, Ophthalmic drug delivery