Histamine determination in tears as an index of safety in use of cosmetic products |
| |
Authors: | A. BETTERO M. R. ANGI F. GALIANO C. A. BENASSI |
| |
Affiliation: | Department of Pharmaceutical Sciences, University of Padova, Italy;Department of Ophthalmology, University of Padova, Italy |
| |
Abstract: | To assess ocular irritancy caused by chemical and cosmetic products a reliable method based on evaluation of histamine (Hm) in tears is presented. Hm is measured at picomole levels by HPLC and fluorimetric detection after fluorescamine-HM derivatization. In order to avoid any uncontrolled irritation and stimulation of the conjunctiva during sample collection, a procedure of conjunctiva lavage was developed. A balanced salt solution (50 μl) containing a known amount of Hm-fluorophore as reference standard is instilled in the conjunctiva fornix. After a few seconds 20 μl of tear fluid is collected: 10 μl are immediately analysed and 10 μl after derivatization reaction. In this way it is possible to evaluate tear dilution and to assess Hm content in less than 10 minutes. In a group of 20 normal subjects Hm has been determined in comparison with that of two volunteers after topical application of 50 μ of 0.2% and 0.4% sodium lauryl sulphate solution. A contact of 30 seconds of the cosmetic ingredient caused an immediate dose-dependent Hm release through a direct cytotoxic damage of cell membranes due to the surfactant action. Évaluation de l'irritation occulaire due aux cosmétiques par la détermination de l'histamine lacrimale |
| |
Keywords: | ocular irritancy fluorescamine-histamine derivatization fluorophore reference standard conjunctival lavage fluid histamine-release |
|