Validating and troubleshooting ocular in vitro toxicology tests

Abstract

In vitro organotypic models for testing ocular irritants have warranted sufficient interest as methods to replace in vivo ocular testing. The in vitro organotypic models claim to maintain short-term normal physiological and biochemical function of the mammalian cornea in an isolated system. In these test methods, damage by the test substance is assessed by quantitative measurements of changes in corneal opacity and permeability using opacitometry and spectrophotometry, respectively. Both measurements are used quantitatively for irritancy classification for prediction of the in vivo ocular irritation potential of a test substance. Examples of organotypic models that incorporate these criteria include: the bovine corneal opacity and permeability (BCOP) assay, the isolated chicken eye (ICE) test method and the isolated rabbit eye (IRE) assay. A fourth method, the hen's egg test-chorioallantoic membrane (HET-CAM) assay, differs in the evaluation criteria but is also normally included among this class of in vitro protocols. Each of these protocols is discussed in detail as representative candidate in vitro methods for assessing ocular irritation and corrosion. The methodologies, protocol details, applications, and their validation status are discussed. A brief historical perspective of the development of original in vitro ocular testing models is also mentioned. More importantly, improvement and troubleshooting the current techniques, in order to present the models as stand-alone in vitro tools for ocular toxicity assessment, is emphasized.

Bacterial Derivatives of Lactococcus lactis and Ectoin for Atopic Dermatitis: Dermal Compatibility and Cosmetic Acceptability

“…However, the use of probiotics and bacterial derivatives to re-establish the skin barrier and improve the condition represents a new therapeutic development. In the HET CAM in vitro test for potential irritants (now considered a viable alternative to in vivo testing on rabbits [35]), the product being classified as moderately irritant. These results were close to other products of the same cosmetic category (body moisturizing lotions for babies and facial moisturizers for adults), thus, equally well tolerated as these existing products.…”

Kozmetik Ürünlerin Göz İrritasyon Potansiyellerinin Değerlendirilmesinde Geleneksel ve Alternatif Yöntemler

“…Oküler organotipik modeller, göz veya korneanın fizyolojik ve biyokimyasal fonksiyonlarının kısa süreli olarak sürekliliğini sağlayan izole sistemlerdir (15). Bu testlerde test maddesinin genellikle seyreltilmeden uygulanması, insandan elde edilen kazara maruziyet sonuçlarına göre daha güvenilir sonuçlar vermektedir (40).…”

“…Kornea donukluğu (opasitesi), epitelde ve korneal stromada hasar, protein denatürasyonu, şişlik ve vakuolizasyonun göstergesi olarak kabul edilir. Ancak, opasite ölçümleri, sübjektif gözlemsel verilere dayanır (15). Diğer taraftan, ex vivo yöntemlerde Fluorescein Leakage testi de korneadan penetrasyonun ölçüldüğü diğer bir testtir.…”

“…Yukarıdan aşağıya yaklaşımlar şiddetli irritan maddelerin tanımlanmasını, aşağıdan yukarıya yaklaşımlar ise irritan olmayan maddelerin tanımlanmasını kapsar (15,64). İki test yöntemi (EpiOcular™ EIT ve SkinEthic™ HCE) bu yaklaşım için uygun görülmüştür.…”

A Reassessment of the in vitro total protein content determination (TPC) with SIRC and 3T3 cells for the evaluation of the ocular irritation potential of shampoos: comparison with the in vivo Draize rabbit test

“…Cosmetics are among the most controversial products which use animal tests to assess the skin and eye irritation. This is a crucial issue, especially in the European Community countries that demand new initiatives and commercialization of "crueltyfree cosmetics" (McNamme et al, 2009;Barile, 2010). The Draize eye irritation test is a test recommended by the international guidelines for the safety assessment of the chemicals (Scott et al, 2010) and it is the only test accepted by some regulatory agencies, e.g., Brazilian National Health Surveillance Agency (ANVISA), to assess the eye irritation potential.…”