Ocular powder: dry topical formulations of timolol are well tolerated in rabbits.
Average rating
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Star rating
Your vote was cast
Thank you for your feedback
Thank you for your feedback
Authors
Hardarson, Sveinn HákonSigurdsson, Hákon Hrafn
Níelsdóttir, Gudrún Eva
Valgeirsson, Jón
Loftsson, Thorsteinn
Stefánsson, Einar
Issue Date
2006-10-01
Metadata
Show full item recordCitation
J Ocul Pharmacol Ther 2006, 22(5):340-6Abstract
Purpose: Although eye drops are the most common form of ocular drugs, they have several limitations. Drug absorption into the eye is, in general, less than 5%, addition of preservatives is often necessary, and many drugs cannot be formulated as eye drops. Formulating ocular drugs as powder may solve these problems. The aim of this study was to investigate ocular irritation in rabbits following powder administration. Methods: Timolol maleate (TM) powder was administered to pigmented lop rabbits. Both pure TM powder and freeze-dried with PVP-polymer (2.4% of mass) were tested in 1.0- and 0.1-mg doses. Additionally, 4 rabbits received 0.1 mg of the pure powder 3 times a day for 8 d. Redness of the bulbar conjunctiva and the amount of discharge was rated from photographs (0-3 points, randomized and masked evaluation). The 8-d experiment additionally included examination with a slit lamp and examination of hematoxylin-eosin stained sections of eyes with light microscopy. Results: No serious or irreversible signs of irritation were noted. Doses of 1.0 mg were more irritating than 0.1-mg doses. There was no detectable difference in irritation between pure or freeze-dried powder. Slit-lamp examination, surface photographs and histology showed a negligible difference between drug and control eyes following the 8-d experiment. Conclusions: The results suggest that 0.1 mg of timolol powder does not irritate the eye and that testing topical timolol powder in humans is feasible.Description
To access Publisher full text version of this article. Please click on the hyperlink in Additional Linkae974a485f413a2113503eed53cd6c53
10.1089/jop.2006.22.340
Scopus Count
Collections
Related articles
- New mucoadhesive chitosan film for ophthalmic drug delivery of timolol maleate: in vivo evaluation.
- Authors: Fulgêncio Gde O, Viana FA, Ribeiro RR, Yoshida MI, Faraco AG, Cunha-Júnior Ada S
- Issue date: 2012 Aug
- Improved ocular: systemic absorption ratio of timolol by viscous vehicle and phenylephrine.
- Authors: Kyyrönen K, Urtti A
- Issue date: 1990 Sep
- Short-term ocular toxicity and eye irritation tests following application of sufentanil in rabbits.
- Authors: Chen H, Chen Z, Xu Y
- Issue date: 2014 Dec
- Topical timolol, at conventional, unilateral doses causes bilateral ocular beta-blockade in rabbits.
- Authors: Woodward DF, Dowling MC, Feldmann BJ, Chen J
- Issue date: 1987 Feb
- The transcorneal penetration of commercial ophthalmic formulations containing timolol maleate in rabbit eyes.
- Authors: Fukuda M, Sasaki H
- Issue date: 2015 Feb