W/O microemulsions for ocular delivery : evaluation of ocular irritation and precorneal retention

Alany, R.G., Rades, T., Nicoll, J., Tucker, I.G. and Davies, N.M. (2006) W/O microemulsions for ocular delivery : evaluation of ocular irritation and precorneal retention. Journal of Controlled Release, 111(1-2), pp. 145-152. ISSN (print) 0168-3659

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Water-in-oil microemulsions (w/o ME) capable of undergoing a phase-transition to lamellar liquid crystals (LC) or bicontinuous ME upon aqueous dilution were formulated using Crodamol EO, Crill 1 and Crillet 4, an alkanol or alkanediol as cosurfactant and water. The hypothesis that phase-transition of ME to LC may be induced by tears and serve to prolong precorneal retention was tested. The ocular irritation potential of components and formulations was assessed using a modified hen's egg chorioallantoic membrane test (HET-CAM) and the preocular retention of selected formulations was investigated in rabbit eye using gamma scintigraphy. Results showed that Crill 1, Crillet 4 and Crodamol EO were non-irritant. However, all other cosurfactants investigated were irritant and their irritation was dependent on their carbon chain length. A w/o ME formulated without cosurfactant showed a protective effect when a strong irritant (0.1 M NaOH) was used as the aqueous phase. Precorneal clearance studies revealed that the retention of colloidal and coarse dispersed systems was significantly greater than an aqueous solution with no significant difference between ME systems (containing 5% and 10% water) as well as o/w emulsion containing 85% water. Conversely, a LC system formulated without cosurfactant displayed a significantly greater retention compared to other formulations.

Item Type: Article
Research Area: Chemistry
Faculty, School or Research Centre: Faculty of Science, Engineering and Computing (until 2017) > School of Pharmacy and Chemistry
Related URLs:
Depositing User: Sergei O'Farrell
Date Deposited: 05 May 2017 15:57
Last Modified: 05 May 2017 15:57
DOI: https://doi.org/10.1016/j.jconrel.2005.11.020
URI: http://eprints.kingston.ac.uk/id/eprint/31905

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