Module 3R    Draize test replacement Author: Frank Straube
The Draize test and its replacement and validation A A A
Welcome !
Module 3R
Draize test replacement
Eye irritation
Draize Test
Problems
Standard deviation
Correlation
Validation
In vitro model
Experimental set-up
MTT-test
Referential standards
Histopathology
Sensitization in-vitro?
Pain
Tox receptor
Implementation of the 3Rs
Pyrogen test in vitro
Replacement
Receptor modeling
3R-Bologna declaration
Authors
Continuing Education
Contact
Today the Draize test is only carried out with substances that in vitro, show no effects. The pre-validation study that is introduced here is an attempt to completely replace the Draize Test. It should also be seen as an example of the required procedure, for the introduction of new tests, in the area of toxicity testing.
Inhaltsverzeichnis
Eye irritation caused by chemicals
What pictures communicate, what pictures can suggest. Testing on rabbit’s eyes, when the result shows no overall effect.
The Draize test for the ascertainment of eye irritation
An old test from the 1940’s which is not getting any better, but is useful as a reference for new in vitro tests.
The problematical side of the Draize test
A test with high variability in various laboratories,as a measurement norm for alternative methods
A validation of the Draize test
High standard deviation and variation coefficients in the "Golden Standard" for eye irritation
Effect of variability on the correlation of the method
What should be done, when the standard test produces variable results?
Validation of alternative methods
From the development of the test, up to acceptance by the authorities. How can we be sure that alternative methods will provide good predictions of results?
Pre-validation of an in vitro model
Assessment of the irritative potential on the eye, with the help of an in vitro model with a human Cornea epithel. The laboratories of the pharmaceutical industry take the lead.
Test on an in vitro generated cornea epithel
The arrangement of the test, simulates the situation, of a contact by the substance tested on the eye. Countless structural and functional changes can as a result be measured.
Functional changes : Assessment of the Mitochondria function
The colour change of the indicator is a sensitive marker for the mitochondrial activity in the cell.
Differentiated results can be expected
The testing of representative chemicals with known activity is an important part of the validation of the method.
Structural changes : Histopathology
The pre-validation is made in advance of the formal validation. The histological examinations, serve the verification of functional changes.