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
Currently, it is generally accepted that no single in vitro eye irritation test will be able to replace the in vivo Draize eye test
to predict across the entire range of irritation for different chemical classes. Several labs (including MB Research) have been working on strategic combinations of several in vitro and alternative test methods within a (tiered) testing strategy that could replace the Draize Rabbit Eye Test.
Available In Vitro & Alternative Eye Irritation 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.
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.
MB Research Labs is a leader in the US for development and validation of in vitro alternative test methods that reduce/replace the need for using live animals in product safety testing of consumer products, chemicals, pharmaceuticals and cosmetics.
MB Research Labs is a leading in vitro toxicology laboratory that offers toxicological testing services to the cosmetic, chemical and pharmaceutical industries.
One of the more important assays offered in the 3T3 Neutral Red Uptake Phototoxicity (3T3 NRU PT) Assay. The 3T3NRUPT is used to screen test materials for the potential of causing photoirritation after exposure to the material and sunlight.
The 3T3 NRU PT was developed and validated in a joint EU/COLIPA project from 1992-1997. In 1996, the 3T3 NRU PT was recommended by OECD as an in vitro approach for the assessment of chemicals phototoxicity potential. In April 2004, the 3T3 NRU PT protocol was finalized and adopted as the OECD 432 protocol, In Vitro 3T3 NRU phototoxicity test.
The 3T3 NRU PT can be utilized to identify the phototoxic effect of a test substance induced by the combination of test substance and light and is based on the comparison of the cytotoxic effect of a test substance when tested after the exposure and in the absence of exposure to a non-cytotoxic dose of UVA/vis light. Cytotoxicity is expressed as a concentration-dependent reduction of the uptake of the vital dye – Neutral Red.
Substances that are phototoxic in vivo after systemic application and distribution to the skin, as well as compounds that could act as phototoxicants after topical application to the skin can be identified by the test. The reliability and relevance of the 3T3 NRU PT have been evaluated and has been shown to be predictive when compared with acute phototoxicity effects in vivo in animals and humans.
Cosmetics are required to be safe when consumers use them according to directions in the labeling, or in the customary or expected way.
To ensure the safety of a cosmetic product, manufacturers may conduct cosmetic safety testing.
Cosmetic products and ingredients (except for color additives) do not require FDA approval before being released on the market.
The FDA does not have a list of mandatory tests required for any particular cosmetic product or ingredient. Action can be taken against the manufacturer of a cosmetic on the market if we have reliable
information to show that a cosmetic does not meet the legal requirement for safety.
Color additives are treated differently. Unlike other cosmetic ingredients, color additives (other than coal-tar hair dyes and related materials)
must be approved by the FDA for the specific intended use before they are permitted in cosmetic products.
Your Cosmetic Safety Testing Partner
MB Research has been conducting product safety assessments for the cosmetics, personal care, chemical and pharmaceutical industries for over 40 years and is often sought out by Cosmetics Industry Leaders to ensure the safety their ingredients and aid in the rapid development of products.
We are a leader in the use and development of In Vitro and Alternative Toxicology Tests and continue to introduce new testing methods regularly.
Cosmetic, Beauty and Healthcare product industries are subject to global regulatory requirements such as the EU Cosmetics Directive (76/768/EEC) in response to growing concern over the safety of cosmetic products and their ingredients.
Weigh of Evidence (WoE) testing with in vitro test methods is now being accepted by European chemical agencies to satisfy REACH requirements. This is especially helpful when specific regulatory guidelines require complex safety testing but no validated in vitro test or alternative assay exists.
WoE must be accompanied with substantial background data to aid in acceptance of our provided safety data. GLPs are a must.
MB Research Labs offers many in vitro test methods that are directly in-line with some regulatory testing requirements as well as novel in vitro test that have not been accepted yet but can still provide a strong case for safety assessments.
Pan-American Conference for Alternative Methods (PACAM), April 12-14, 2016, hosted by Johns Hopkins University
MB Research Labs will be attending the PACAM conference. The PACAM brings together experts and stakeholders from across the Americas, with a focus on the Six Rs: Replacement, Reduction, Refinement, Read-across, Relevance, and Roadmaps.
MB Research Labs is serving on the organizing committee. MB Research Chief Scientific Officer, Dr. George DeGeorge and Director of Toxicology, Bennett Varsho, will be presenting informative talks on in vitro toxicology methods: the In Vitro Sensitization Assay (IVSA) and the Human Cell Line Activation Test (h-CLAT) as well as presenting scientific posters.