Validation Activities
In spite of intensive effort over the last twenty years, there are still only a few in vitro assays for acute endpoints that are internationally accepted as validated. However, many industrial organizations use multiple in vitro assays on a daily basis to make safety and efficacy decisions. Because of the many pressures today pushing industry towards the use of non-animal methods, it seems likely that it is only a matter of time before a much larger number of assays are validated, at least for carefully defined ranges of toxicity and chemical activity. Standardized, validated assays that provide dependable, predictive safety data for the broad range of products in the cosmetic, personal care, chemical, household products and pharmaceutical industries will be needed in greater numbers as each year passes.
Factors influencing the speed of validation and regulatory acceptance of in vitro assays include:
- the availability of human correlation data
- the availability of reliable and relevant animal data correlated to the human response
- the benefits of obtaining more sophisticated, human-specific data
- the significant expense and time required to complete multi-phase validation studies
Government and private industry are working toward the validation of assays that can be used for product safety evaluation by appropriate regulatory agencies throughout the US and Europe. IIVS participates in many of the Government sponsored projects and assists individual companies and consortiums by organizing validation programs itself. Some of the current activities and organizations active in validation are:
US (http://iccvam.niehs.nih.gov/): The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) was established as a collaborative effort by 14 regulatory and research agencies in the US to coordinate programs relevant to the development, validation and acceptance of new Toxicological test methods. Documents, including protocols, experimental design, chemical database, can be obtained from ICCVAM (http://iccvam.niehs.nih.gov/methods/invitro.htm).
Europe: The European Center for the Validation of Alternative Methods (ECVAM) was founded by the European Union to take a lead in validating alternative methods for use in the European regulatory environment. ECVAM acts as a focal point for exchange of information on alternative methods, establishes and maintains an in vitro database. Information on ECVAM Home Page (http://ecvam.jrc.it/index.htm)
Recently completed and ongoing programs include the following:
Acute Systemic Toxicity: “The In Vitro Cytotoxicity Validation Study is a joint effort of NICEATM and ECVAM. It generates in vitro toxicity data using neutral red uptake assays with rodent (mouse fibroblast 3T3) and human (normal human keratinocyte) cells to predict rodent in vivo LD50 data and human in vivo mortality data so as to further the development of in vitro predictive models for human acute toxicity.”
Dermal Corrosivity and Irritation
Ocular Toxicity
- ICCVAM: In Vitro Screening Test Methods for Severe Eye Irritants
(http://iccvam.niehs.nih.gov/methods/eyeirrit.htm)
- ECVAM: An ECVAM Task Force is gathering performance information on a number of in vitro ocular methods. It is expected that the full review of these methods will be conducted early in 2005.
Federal Register Notices
- Federal Register Notice (69 FR 21565, April 21, 2004) (http://iccvam.niehs.nih.gov/docs/FR/6921565.htm): Request for Nominations of Scientific Experts for Independent Expert Panel Evaluations and/or other Reviews of In Vitro Testing Methods for Identifying Potential Ocular Irritants
- Federal Register Notice (69 FR 13859, March 24, 2004) (http://iccvam.niehs.nih.gov/docs/FR/6913859.htm): Request for Public Comment on the Nomination for Ocular Toxicity Test Methods and Related Activities and Request for Data on Chemicals Evaluated by In Vitro or In Vivo Ocular Irritancy Test Methods. [HTML or PDF] - Example Data Page
Phototoxicity
- ICCVAM: In Vitro 3T3 NRU Phototoxicity
(http://iccvam.niehs.nih.gov/methods/3t3_nru.htm)
- ECVAM: 3T3 Neutral Red Uptake (NRU) phototoxicity test – validated assay
Date of the ESAC statement: 20 May 1998, 03 November 1997
Links: INVITTOX Protocol, ESAC Statement
- OECD: Test Guideline 432 In Vitro 3T3 NRU Phototoxicity Test view web page
Revised and approved by the National Co-ordinators in May 2002, approved by Council April 2004
Endocrine Disruptors (http://iccvam.niehs.nih.gov/methods/endocrine.htm)
- ICCVAM: At the request of the U.S. EPA, ICCVAM and NICEATM convened an independent panel of scientists, May 21-22, 2002, in Research Triangle Park, NC, to assess the validation status of four different types of in vitro assays proposed as screens to identify chemicals with potential hormonal activity. The assays, estrogen receptor (ER) and androgen receptor (AR) binding assays, and ER and AR transcriptional activation assays, were evaluated. The panel also developed proposed minimum performance standards (MPS) for future methods to achieve and proposed substances for validation of the methods. Report and public comments can be found in the Federal Register Notice (69 FR 21564, April 21, 2004): In Vitro Endocrine Disruptor Test Methods: Request for Comments and Nominations.
Developmental Toxicity
OECD Test Guidelines
- TG 428 Skin absorption: In Vitro Method view web page
Revised and approved by the National Co-ordinators in May 2002, approved by Council April 2004
- TG 430 In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER) view web page
Revised and approved by the National Co-ordinators in May 2002, approved by Council April 2004
- TG 431 In Vitro Skin Corrosion: Human Skin Model Test view web page
Revised and approved by the National Co-ordinators in May 2002, approved by Council April 2004
- TG 432 In Vitro 3T3 NRU Phototoxicity Test view web page
Revised and approved by the National Co-ordinators in May 2002, approved by Council April 2004
