Ocular Drug Delivery System Pdf

Review on insitu-gelling opthalmic drug delivery system. Structurally, niosomes are similar to liposomes, in that they are also madeup of a bilayer. Advancement in therapy of eye diseases. Now customize the name of a clipboard to store your clips. Anterior segment of the eye occupies approximately one-third while the remaining portion is occupied by the posterior segment.

Jitendra Badjatya

Ocular drug delivery systems An overview

In the current era of nanotechnology, these conventional formulations still retain their place, importance and capture the market at large. The lamellae provide physical strength while permitting optical transparency.

Diclofenac-loaded biopolymeric nanosuspensions for ophthalmic application. Though considerable effort is being put into research to improve efficacy, still there is a need to overcome certain drawbacks associated with conventional formulations. Several attempts are also being made to deliver drugs to posterior ocular tissues with conventional formulations.


Emulsions An emulsion based formulation approach offers an advantage to improve both solubility and bioavailability of drugs. Corneal penetration and absorption. Therefore, cyclodextrins remain in aqueous solution and the hydrophobic drug is absorbed by the biological membrane.

Dendrimers Dendrimers are characterized as nanosized, highly branched, star shaped polymeric systems. Active ion transport at cornea. Comparative study of treatment of the dry eye syndrome due to disturbances of the tear film lipid layer with lipid-containing tear substitutes.

Ocular disposition, pharmacokinetics, efficacy and safety of nanoparticle-formulated ophthalmic drugs. These are classified as conventional and non-conventional newer drug delivery systems. Lipid emulsions as a potential delivery system for ocular use of azithromycin. To circumvent the protective barriers like drainage, lacrimation and conjunctival absorption. Long term drug release may be achieved with these non-biodegradable implants but are associated with certain short comes.

Interaction of drug with proteins oflacrimal fluid. Pharmacokinetics and tolerance study of intravitreal injection of dexamethasone-loaded nanoparticles in rabbits. Size-dependent disposition of nanoparticles and microparticles following subconjunctival administration. Vijayalakshmi Kalaga Follow. Long-term follow-up results of a pilot trial of a fluocinolone acetonide implant to treat posterior uveitis.

Submicron-sized liposomes ssLips and multilamellar. Remember me on this computer. Although transscleral delivery is comparatively easy, less invasive and patient compliant, drug permeation is compromised by ocular static and dynamic barriers. Dexamethasone transport and ocular delivery from poly hydroxyethyl methacrylate gels.

An update of current research advancement in ocular drug delivery necessitates and helps drug delivery scientists to modulate their think process and develop novel and safe drug delivery strategies. Dendrimers are being employed as carrier systems in drug delivery. Effect of hydroxypropyl beta cyclodextrin complexation on aqueous solubility, stability, and corneal permeation of acyl ester prodrugs of ganciclovir.

Ocular drug delivery systems


Enhanced antiproliferative activity of carboplatin-loaded chitosan-alginate nanoparticles in a retinoblastoma cell line. Journal of Adv Pharma Tech.

In addition, higher extent of drug absorption and more intense drug effects were observed for all steroids form nanosuspensions compared with solutions. The kinetics of drug concentration decline may follow an approximate first order. At the surface, epithelial cells are connected by tight junctions, which render the conjunctiva relatively impermeable.

Micellar constructs were observed to selectively accumulate at the pathologic neovascular site to a greater extent than in normal tissues. The choroid layer, situated inside the sclera, contains many blood vessels and is modified at the front of the eye as pigmented iris. Episcleral, intrascleral and suprachoroidal routes have the advantage of bypassing the main barriers to topical drug penetration.

For posterior segment delivery, disposition of nanoparticles depends on the size and surface property. Nonetheless, the ocular bioavailability is very low with topical drop administration. Results suggest that nanomicellar formulations are a viable option for topical ocular delivery of small molecules. The choice of hydrocarbon is dependent on biocompatibility.

On the other hand, advent of nanotechnology, new techniques, devices and their applications in drug delivery is developing immense interest to ocular scientists. In near future, dreamweaver cc visual quickstart guide pdf this delivery system may replace invasive mode of drug administration to back of the eye such as periocular and intravitreal injection.

Support Center Support Center. These results imply that intravitreal injection of dexamethasone nanoparticles may be employed for sustained delivery of drugs for the treatment of posterior segment eye diseases. Thermoresponsive hydrogels as a new ocular drug delivery platform to the posterior segment of the eye. Highly lipophilic biological membrane has much lower affinity towards hydrophilic cyclodextrins. Anterior segment drug delivery advances are witnessed by modulation of conventional topical solutions with permeation and viscosity enhancers.

The eye is a complex organ with an unique anatomy and physiology. Some studies on the preservation of indometacin suspensions intended for ophthalmic use. Difficulty in placement and removal. Inner Core - Pilocarpine gelled with alginate main polymer. Viscosity enhancers improve precorneal residence time and bioavailability upon topical drop administration by enhancing formulation viscosity.

Tissues such as cornea, conjunctiva, aqueous humor, iris, ciliary body and lens make up the anterior portion. Hence, research is still being conducted to modify the effect of permeation enhancers and evaluate their safety on corneal tissues. Photocoagulation was induced in rat eye. Delivery of drugs to the targeted ocular tissues is restricted by various precorneal, dynamic and static ocular barriers.

Cadaver eyes were used to evaluate the role and scleral penetration of microneedle and intrascleral dissolution of microneedle surface coated drug sulforhodamine. The implant had effectively controlled inflammation, reduced uveitis recurrences and improved vision acuity. However, the bilayer in the case of niosomes is made up ofnon-ionic surface active agents rather than phospholipids as seen in the caseof liposomes. Also, adverse events such as endophthalmitis, pseudoendophthalmitis, vitreous haze and hemorrhage, cataract development and retinal detachment limit their applications.

Retinal drug delivery using eyedrop preparations of poly-l-lysine-modified liposomes. Outer layer - ethylene vinyl acetate copolymer layer.

This study suggests difluprednate emulsion as a potential candidate for treating anterior ocular inflammations. In general, these nanomicelles are made with amphiphilic molecules. For most topically applied drugs, passive diffusion along their concentration gradient, either transcellularly or paracellularly, is the main permeation mechanism across the cornea. In vivo studies were conducted in male New Zealand albino rabbits with a topical drop instillation. This review will provide an overview on various conventional and novel ophthalmic drug delivery systems developed to deliver drug to diseased ocular tissues for the treatment of ocular diseases.