Ocular drug delivery

Lee, V.H.L. Robinson, J.R. "Review topical ocular drug delivery recent developments and future challenges" Journal of Ocular Pharmacology, 1986,1,67. 

An erodible insert developed as a potential ocular drug-delivery system is marketed as a prescription drug for the lubricant properties of the polymer base. Lacrisert is a sterile ophthalmic insert used in the treatment of moderate to severe dry eye syndrome and is usually recommended for patients unable to obtain symptomatic relief with artificial tear solutions. The insert is composed of 5 mg of hydroxypropylcellulose in a rod-shaped form about 1.27 mm diameter by about 3.5 mm long. No preservative is used, since it is essentially anhydrous. The quite rigid cellulose rod is placed in the lower conjunctival sac and first imbibes water from the tears and after several hours forms a... 

A. K. Mitra, ed. Ocular Drug Delivery Systems, Marcel Dekker, New York, 1993. 

J. Liaw and J. R. Robinson, Ocular penetration en-chancers, in Ocular Drug Delivery Systems (A. K. Mitra, ed.), Marcel Dekker, 1993, pp. 369-381. 

Prodrugs Topical and Ocular Drug Delivery, edited by Kenneth B. Sloan... 

NM Davies, SJ Farr, J Hadgraft, IW Kellaway. (1991). Evaluation of mucoadhesive polymers in ocular drug delivery. I. Viscous solutions. Pharm Res 8 1039-1043. 

VHL Lee. (1993). Improved ocular drug delivery by use of chemical modification (prodrugs). In P Edman, ed. Biopharmaceutics of Ocular Drug Delivery. Boca Raton, FL, CRC Press, pp 121-143. 

Octynoic acid, 5 34t Ocular drug delivery, 9 50 Ocular infections, sulfonamides for, 23 499 ODA/PPTA fibers, uses for, 19 734-735 Oddy test, in fine art examination/ conservation, 11 409 O-dealkylation, 9 441 Odometric titration method, 14 59 Odontalag, molecular formula and structure, 5 9 It Odor... 

J. J. Yang, H. Ueda, K. Kim, and V. H. Lee. Meeting future challenges in topical ocular drug delivery Development of an air-interfaced primary culture of rabbit conjunctival epithelial cells on a permeable support for drug transport studies. J Control Release 65 1-11 (2000). 

Since most eye medications need to enter the eye for a pharmacological effect, ocular drug delivery is a major issue in ocular research. Generally, three routes into the eye have been described in the literature [24] ... 

The transcorneal route. This is still the major pathway for ocular drug delivery, representing the direct pathway into the eye and is applicable for most of drug substances. 

If the medical drug is applied topically to the eye, another important factor for ocular drug delivery and penetration has to be taken in account that is, the precorneal clearance which rapidly reduces the drug amount available for penetration. Thus, it is a major factor to take into consideration while evaluating (transcorneal) absorption. So far, due to experimental limitations, not much thought has been given to precorneal clearance in cell-based in vitro models. 

Keywords Ocular drug delivery Noncorneal route Transporters Iontophoresis Endocytosis Dry eye Inflammation Subconjunctival injections... 

Chapter 13 The Conjunctival Barrier in Ocular Drug Delivery 309... 

K. Hosoya, V. H. Lee, and K. J. Kim. Roles of the conjunctiva in ocular drug delivery a review of conjunctival transport mechanisms and their regulation. Eur J Pharm Biopharm 60 227-240 (2005)... 

The following types of mucoadhesive preparations have been evaluated for ocular drug delivery hydrogels, viscous liquids, solids (inserts), and particulate formulations [57]. Hui and Robinson [58] introduced hydrogels consisting of cross-linked polyacrylic acid for ocular delivery of progesterone in rabbits. These preparations increased progesterone concentrations in the aqueous humor four times over aqueous suspensions. 

Alonso MJ, Sanchez A. The potential of chitosan in ocular drug delivery. J Pharm Phar-maco 2003 55 1451. 

The synchronized movement of the eyelids spreads the precorneal tearfilm across the cornea and pushes it toward the nasolacrimal duct. Precorneal drainage is quite efficient. An aqueous instilled dose leaves the precorneal area within 5 min of instillation in humans. Most of the drug absorbed by transcorneal penetration, without retention modification, is spread across the cornea by the eyelids in the first minutes postdosing. In the precorneal space transcorneal penetration is limited by solution drainage, lacrimation and tear dilution, tear turnover, conjunctival absorption, and the corneal epithelium. Slowing down tear film turnover has well-established benefits to topical ocular drug delivery. 

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