Corrositex® is an in vitro method used to determine the dermal corrosive potential of chemicals and chemical mixtures.
Corrositex® has been designed as a replacement for the dermal corrosivity rabbit test based upon proprietary biomembrane and chemical detection technology. Corrositex® is also OECD approved – OECD Test Guideline 435: Non-Animal Dermal Corrosivity Test for Packing Group Classification.
* For two (2) or more samples sent together; Single (1) sample price: $995
Evaluate the mutagenic potential of a test article based on the reversion of selective growth mutations
The purpose of this study is to evaluate the mutagenic potential of a test article based on the reversion of selective growth mutations in several strains of Salmonella typhimurium bacteria and in Escherichia coli WP2 uvrA bacteria, in the presence and absence of S9 activation. This protocol is based on OECD Guideline for Testing of Chemicals: No. 471 – Bacterial Reverse Mutation Test and U.S. EPA Health Effects Test Guidelines OSCPP/OPPTS 870.5100 – Bacterial Reverse mutation Test. MB Research Labs utilizes the test guideline recommended bacterial strains (E. coli WP2 uvrA , S. typhimurium TA97a, S. typhimurium TA98, S. typhimurium TA100, and S. typhimurium TA1535). More information available here.
Basis of the Method:
The test system will be exposed to the test article via the plate incorporation method, which has been shown to effectively detect a wide variety of mutagenic compounds. This assay is based on the methodology originally described by Ames, et al. (1975) and updated by Maron and Ames (1983) and complies with the Guidelines.
In general, a 2-fold increase with or without metabolic activation will be considered a positive response. Dose-related increases approaching a 2-fold increase will be deemed equivocal and a repeat test will be recommended.
Negative Results will be determined by the absence of a dose-related increase in all five tester strains, again taking into account toxicity of the test article as well as the quality checks of the assay.
Positive Results from the bacterial reverse mutation test indicate that the substance induces point mutations by base substitutions or frame shifts in the genome of either Salmonella typhimurium and/or Escherichia coli. Negative results indicate that under the test conditions, the test substance is not mutagenic in the tested species.
This study is conducted in accordance with the Good Laboratory Practices of the EPA, 40 CFR 160 and 792, FDA 21 CFR Part 58, and as specified in the OECD, Principles on Good Laboratory Practice, revised 1997.
1. B. N. Ames, J. McCann, and E. Yamasaki. Methods for detecting carcinogens and mutagens with the Salmonella/mammalian-microsome mutagenicity test. Mutat Res 31 (6):347-364, 1975.
2. D. M. Maron and B. N. Ames. Revised methods for the Salmonella mutagenicity test. Mutat Res 113 (3-4):173-215, 1983.
3 L. D. Claxton, J. Allen, A. E. Auletta, K. Mortelmans, E. Nestmann, and E. Zeiger. Guide for the Salmonella typhimurium/mammalian microsome tests for bacterial mutagenicity. Mutat Res 189 (2 (Oct)):83-91, 1987.
4. K. Mortelmans and E. Zeiger. The Ames Salmonella/microsome mutagenicity assay. Mutat Res 455 (1-2):29-60, 2000.
5. OECD Guideline for Testing of Chemicals: No. 471 – Bacterial Reverse Mutation Test (July 1997)
6. U.S. EPA Health Effects Test Guidelines OPPTS 870.5100 – Bacterial Reverse mutation Test (August 1998).
The California Cruelty-Free Cosmetics Act makes it unlawful for cosmetic manufacturers to sell any cosmetic in California if the final product or any component of the product was tested on animals and goes into effect Jan. 1, 2020.
Products that have undergone testing on animals before that date can still be sold in California. Earlier in the month, the bill passed the state legislature after it was narrowed in scope.
Are You Ready With In Vitro Testing?
MB Research Labs is positioned to help manufacturers with a suite of in vitro and alternative (non-animal) tests for cosmetic safety testing. MB has over 45 years of toxicology testing experience and over 25 years of testing using non-animal test methods.
The Organization for Economic Co-Operation and Development (OECD) has prescribed the use of a weight-of-evidence (WoE) analysis, integrated with a sequential testing strategy, for the classification of acute eye hazards. The October 2017 revision to the Health Effects Test Guideline No. 405 outlines a stepwise strategy that includes Step 6, “Perform validated and accepted in vitro or ex vivo ocular test(s),” specifying only four possible tests: three designed to identify severe eye irritation/ corrosion (GHS Category 1) and one to identify non-irritants (GHS No Category), the top-down and bottom-up approaches, respectively. The GHS Category 2 (eye irritant) classification is impossible by any one bottom-up or top-down test.
The EpiOcular™ Eye Irritation Test; EIT (OECD 492), as a bottom-up test, either determines a material to be No Category, or that it causes eye effects, but cannot discriminate between eye irritation, serious eye damage, and corrosion.
Conversely, the top-down Bovine Corneal Opacity and Permeability; BCOP Test (OECD 437), is used for ruling in or ruling out Category 1 effects (serious eye damage/corrosion). By using a dual-assay/approach system – the combination of the EIT and BCOP test – we have determined, with a high degree of accuracy, GHS Acute Eye Hazard Category 2 chemicals that cause reversible irritation to the eye.
A Double Elimination occurs when a BCOP test rules out GHS Category 1 (severe irritation/corrosion) and the EIT rules out GHS No Category (non-irritant), analysis of the combined results concludes the only other possible designation – Category 2 (irritant). The classification defaults to Category 2A for labeling and handling purposes because at present differentiation between category 2A and 2B cannot be made. Using this approach, we correctly identified 87% of the Category 2A/B chemicals as Category 2 after testing 42 chemicals (nine, 15, and 18 in Category 1, 2A/B, and No Category, respectively).
As a result of this analysis, we are encouraged by the potential of the BCOP-EIT dual-assay system, coupled with WoE evaluation, to correctly assign unknowns into GHS Category 1, Category 2A, and No Category Acute Eye Hazards without the use of less predictive and more expensive in vitro tests. Moreover, in keeping with the OECD’s recommendations, we predict that such a system would greatly reduce reliance on the Draize Rabbit Eye Tests.
MB Research Labs is honored to be attending the 10th World Congress on Alternatives and Animal Use in the Life Sciences. We will be presenting several posters focusing on the use and development of in vitro and alternative toxicology methods that are used in our laboratories.
Scientific Posters presented by MB Research Labs on the Use and Development of In Vitro and Alternative Toxicology Test Methods
MB Research Labs is now offering the new OptiSafe™ – an in vitro test method in which a test substance is applied to a semi-permeable membrane. Damage to macromolecules in the membrane is measured to assess the test substance’s potential to cause eye irritation.
OptiSafe™ Background Information
OptiSafe™ is an acute in vitro irritation test method used to determine the ocular irritation potential based of a test substances utilizing a set of biochemical tests (mostly performed in parallel; “multiplexed”) which evaluate the potential of the test substance ability to disrupt, denature and degrade biological molecules. These measured values are relevant to GHS and EPA standard ocular safety classification systems.
Evaluated Mechanisms of Ocular Injury and Prediction Models
Different ocular irritants including, acids/bases, alcohols/aldehydes/ketones, strong oxidants and reactive chemicals/mixtures, damage the cornea and other tissues through additive and/or synergistic chemical reactions and biophysical effects.
Evaluated mechanisms of injury include:
Denaturation of specific water insoluble polymers that model the phospholipid bilayer of cells (which can occur at the corneal epithelium and conjunctiva).
Direct denaturation of macromolecules that model ordered collagen (which can occur at the corneal stroma).
Indirect denaturation of molecules across a membrane via osmotic effects (osmotic effects across the corneal epithelium and stroma can damage the cornea).
Potential to damage tissue via excessive oxidation and reactivity (which can occur at the epithelium, stroma, conjunctiva and iris).
Potential to damage tissues via extreme buffering (which can occur at the epithelium, stroma, conjunctiva and iris).
NICEATM reviewed a validation study conducted by the OptiSafe™ test method developer, Lebrun Labs, and concluded that the study data indicated that the OptiSafe™ method compared favorably to other in vitroocular toxicity testing methods. NICEATM is currently coordinating a validation study of the OptiSafe™ test method to demonstrate the reproducibility of the method among Lebrun Labs and two naïve laboratories. The study received support from an NIEHS Small Business Innovation Research grant. The study is ongoing and is expected to be completed in mid-2018.
MB Research Labs is a primary testing source using OptiSafe™ and has been deeply involved in the validation of OptiSafe™.
Utility of OptiSafe™
OptiSafe™ can be used to determine the irritation potential of cosmetics, creams, and a wide variety of consumer products. Results are presented as GHS, EPA classifications, an ocular irritation score and class.
OptiSafe™ can be used for:
Screening Finished Products for Ocular Irritation.
Ocular safety testing during product development for knowledge based formulation. (Products that irritate do not last long in the marketplace).
The Advantages of OptiSafe™ include:
Accurate Ocular Irritancy Test
High Sensitivity for Mild and Moderate Irritants
1 year shelf life
Neither uses nor harms animals
MB Research Labs performs many other in vitro eye and dermal irritation tests for screening of cosmetics, consumer products, pharmaceuticals and chemicals.
OptiSafe™ is a trademark of Lebrun Labs, LLC and used here with permission.
5 Key Points of Test Article Characterization (TAC)
The name under which the article will be tested Include CAS number, lot or batch, if applicable
The list of ingredients making up the test article
The stated concentration of an active ingredient in a test article mixture
The fraction that is the active ingredient (relative to impurities), usually expressed as a percent
The duration for which the test article will remain undegraded under the storage conditions provided
Why is Test Article Characterization (TAC) necessary?
When a study is conducted according to the Good Laboratory Practices regulations (GLPs), providing characterization of the material to be tested (the test article) to the Testing Facility (MB Research) is required.
Do you have characterization of the test article (e.g., Certificate of Analysis, or similar)?
Yes – Please provide this to MB Research prior to study initiation (signing the protocol, beginning the experiment).
No –Select ‘no test article characterization’ on the Sponsor Request section of the MB Research protocol. No further action is necessary. Refer to the GLP Compliance section below.
If yes, was test article characterization/analysis performed according to Good Laboratory Practices (GLPs), Good Manufacturing Procedures (GMPs), or neither*?
Please select GLP, GMP, or non-GLP/non-GMP on the Sponsor Request section of the protocol.
Does your TAC include all five of the following GLP-required parameters?
Yes – The study will be in complete GLP compliance. No further action is necessary.
No – Refer to the GLP Compliance section below.
Good Laboratory Practices (GLP) Compliance
A GLP compliance exception statement appears in the study report when TAC –
(1) is not provided
(2) is not provided prior to study initiation (signing the protocol)
(3) does not include all five of the parameters, and/or
(4) is not performed according to GLPs
MB Research Labs is a contract GLP toxicology lab with over 45yrs of experience in chemical, consumer product and cosmetic safety assessment.
Since 1972, MB Research Labs is a GLP contract research organization (CRO) that has been performing toxicology (acute, subchronic / chronic) and pharmacology studies for leaders in the pharmaceutical, biotechnology, medical device and agrochemical industries and government agencies.
With a wide range of testing protocols available, MB Research Labs offers comprehensive capabilities to to address your unique needs and goals with speed and accuracy.
Our expertise in many areas of in vivo and in vitro testing, research, and safety evaluations is the foundation upon how MB Research serves the pharmaceutical toxicology testing needs of both government and industry.
Complete support services including consultation, protocol development, quality assurance, analytical chemistry and archive facilities are integral components of studies performed at MB.
Our technical and support procedures are in full compliance with OECD, FDA, and EPA.
Your Source for In Vitro & Alternatives to Animal Testing.
Cost Saving Screening Testing
Cosmetics & Personal Care Testing
MB Research Labs is a leader in the use and development of
in vitro and alternative toxicology test methods. We specialize in protocols for Eye and Skin Irritation, Corrosivity, Skin Sensitization, Genotoxicity, and Phototoxicity.
Over 45 Yrs Experience. MB Research Labs has been a primary provider of chemical safety testing services to the chemical and consumer products industries.
MB Research has been accredited by AAALAC International, a private, nonprofit organization that promotes the humane treatment of animals in science through voluntary accreditation and assessment programs since 1975.
Over 50,000 toxicigical studies performed – Extensive expertise in conducting in vivo toxicology
Standardized GLP Protocols available for skin and eye irritation, oral and dermal toxicity, dermal sensitization assays and phototoxicity.
Toxicology Testing Experience You Are Looking For.
With a wide range of in vivo and in vitro test protocols available, MB Research Labs offers comprehensive capabilities to address your unique needs and goals.
MB has decades of expertise in many areas of in vivo and in vitro
testing, research, and safety evaluations, MB Research serves the testing needs of both government and industry. Our complete support services including consultation, protocol development, quality assurance, analytical chemistry and archive facilities are integral components of studies performed at MB. Our technical and support procedures are in full compliance with OECD, FDA, and EPA.
Chemical toxicology studies are routinely performed on a wide variety of compounds. The selection of specific studies to be conducted is based on the intended use of the compound and the applicable regulatory requirements. Protocols for the most commonly implemented regulatory studies are available upon request.
The LLNA-BrdU ELISA is conducted at MB Research Labs and is based upon the OECD 442B Testing Guideline. The LLNA is an alternative toxicology assay for dermal sensitization using CBA/J mice. The LLNA is an alternative to guinea pig studies that require more animals and long test durations.
To determine the sensitizing potential of topically applied test material utilizing the LLNA, and measurement of lymphocyte proliferation by BrdU incorporation detected by ELISA.
Irritation Screen Test:
An initial Irritation Screen is performed using 3-5 highest achievable concentrations. The screen consists of 2 animals per concentration that will be dosed in an identical manner to that of the main test. Ear measurements will be taken prior to dosing on Study Days 1 and 3, and prior to euthanasia on Study Day 6. Measurements taken on Study Days 3 and 6 will be compared to pre- dosing measurements. If there is no effect, or an increase of <25% in ear thickness, the same concentrations will be assayed in definitive test.
However, if significant ear swelling (ES) is present (>25% over control), then an extended screen (Quantitative Irritation Test; QIT) is recommended. The QIT is similar to the Irritation Screen except 4-6 concentrations will be assayed to determine the highest non-irritating concentration.
Definitive Sensitization Test:
The main test will be conducted by topically applying test material to the dorsum of the ears at the 3-5 highest achievable concentrations (100 [liquid only], 50, 25, 10, 5, 2.5, 1, 0.5, etc.), which do not cause severe irritation or overt systemic effects. Ear measurements will be taken on Study Days 1 (prior to first dosing), 3 (approximately 48 hours after initial dosing) and 6 (prior to euthanasia). Animals will be injected with BrdU on Study Day 5, approximately 24 hours prior to euthanasia. Auricular lymph nodes will be collected on Study Day 6, a single-cell suspension will be created and lymph node cells (LNC) will be assayed for BrdU incorporation via ELISA.
A Positive Response is when a Stimulation Index (SI) is greater than or equal to 1.6 (relative to that of control lymph nodes).
A “Borderline Positive Response” is defined as an SI from 1.6 to 1.9; additional information and testing may be needed.