title: Nanocarriers in ocular drug delivery: an update review.
abstract: Controlled drug delivery to eye is one of the most challenging fields of pharmaceutical research. Low drug-contact time and poor ocular bioavailability due to drainage of solution, tear turnover and its dilution or lacrimation are the problems associated with conventional systems. In addition, anatomical barriers and physiological conditions of eye are also important parameters which control designing of drug delivery systems. Nanosized carriers like micro/nano-suspensions, liposome, niosome, dendrimer, nanoparticles, ocular inserts, implants, hydrogels and prodrug approaches have been developed for this purpose. These novel systems offer manifold advantages over conventional systems as they increase the efficiency of drug delivery by improving the release profile and also reduce drug toxicity. Conventional delivery systems get diluted with tear, washed away through the lacrimal gland and usually require administering at regular time intervals whereas nanocarriers release drug at constant rate for a prolonged period of time and thus enhance its absorption and site specific delivery. This review presents an overview of the various aspects of the ocular drug delivery, with special emphasis on nanocarrier based strategies, including structure of eye, its barriers, delivery routes and the challenges/limitations associated with development of novel nanocarriers. The recent progresses in therapy of ocular disease like gene therapy have also been included so that future options should also be considered from the delivery point of view. Recent progress in the delivery of proteins and peptides via ocular route has also been incorporated for reader benefit.
authors.affiliation: Nanomedicine Research Centre, Department of Pharmaceutics, Indo-Soviet Friendship College of Pharmacy, Moga, Punjab, India.
authors.forename: Sheetu
authors.initials: S
authors.lastname: Wadhwa
authors.forename: Rishi
authors.initials: R
authors.lastname: Paliwal
authors.forename: Shivani Rai
authors.initials: SR
authors.lastname: Paliwal
authors.forename: S P
authors.initials: SP
authors.lastname: Vyas
mesh_terms: D000818:Animals; D004333:Drug Administration Routes; D004337:Drug Carriers / Q000008:administration & dosage*; D016503:Drug Delivery Systems / Q000009:adverse effects / Q000379:methods*; D005123:Eye / Q000033:anatomy & histology / Q000187:drug effects; D005128:Eye Diseases / Q000188:drug therapy* / Q000235:genetics / Q000628:therapy; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D053685:Laser Therapy / Q000379:methods; D053758:Nanoparticles / Q000627:therapeutic use*; D036103:Nanotechnology / Q000379:methods*; D033581:Stem Cell Transplantation / Q000379:methods
chemical_list: D004337:Drug Carriers