Progressing Non-Animal Approaches to Safety in India Adip Roy 1 , - - PowerPoint PPT Presentation

Progressing Non-Animal Approaches to Safety in India

Adip Roy1, Gaurav Jain1, Paul Carmichael2 and Andrew White2

1 - Safety & Environmental Assurance Centre, Unilever R&D, 64 Main Road, Whitefield, Bangalore – 560066 2 - Safety & Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Beds, UK – MK44 1LQ

SEAC

‘Safety & Environmental Assurance Centre’

Provide authoritative scientific evidence and expertise so that Unilever can identify and manage:

• Risks for consumers, workers and environment
• Safety of products and supply chain technology
• Environmental impacts
• Sustainability of Unilever’s brands, products & supply

chain

Colworth Science Park, UK

Ingredient Risk Assessment

For any ingredient safety Risk Assessment is a function of: » Hazard – potential harmful effects

• Intrinsic hazard of material
• Safety concerns due to functionality

» Exposure – how much will the consumer be exposed to?

• Normal habits & practices
• Amount of ingredient in product

Exposure Assessment

Risk = Hazard x Exposure Aim is to identify Consumer Exposure Level (CEL) Initial steps in the exposure assessment are:

• Determine product type/format
• Amount of product per use.
• Frequency of use.
• Level of ingredient in product.

Determination of the product type informs on the potential route(s) of exposure.

Can We Use A New Ingredient Safely?

Will it be safe

• For our consumers?
• For our workers?
• For the environment?

Can we use x% of ingredient y in product z?

Toxicity Endpoints (Human Health)

Relevant toxicity endpoints based on the Scientific Committee on Consumer Products guidance document “Notes of Guidance for the Testing of Cosmetic Substances and their Safety Evaluation”

• Acute toxicity
• Corrosivity and irritation
• Skin sensitisation
• Dermal/percutaneous absoprtion
• Repeated dose toxicity
• Reproductive toxicity
• Mutagenicity/genotoxicity
• Carcinogenicity
• Toxicokinetic studies
• Photo-induced toxicity

How Do We Assure Safety of Ingredients

Legislation (in place in most countries) requires Companies to ensure that any cosmetic products they put on the market do not cause any adverse health effects when applied under normal or reasonably foreseeable conditions of use. Regardless of whether legislation exists or not, Unilever requires that all products it places on the market must be safe for use We use scientific evidence-based risk assessment methodologies to ensure that the risk of adverse health and/or environmental effects from exposure to chemicals used in our products is acceptably low.

Unacceptable risk Acceptable risk

Safety Assessment Process for Ingredients in Consumer Products

Consider product type and consumer habits Determine route and amount of exposure Identify toxicological endpoints of potential concern Identify critical end point(s) for risk assessment Identify available toxicology data Identify supporting safety data (e.g. QSAR, HoSU) Evaluate required vs. available support Conduct risk assessment for each critical endpoint Conduct toxicology testing as required Overall safety evaluation for product – define acceptability and risk management measures

Safety Assessment Process for Ingredients in Consumer Products

Consider product type and consumer habits Determine route and amount of exposure Identify toxicological endpoints of potential concern Identify critical end point(s) for risk assessment Identify available toxicology data Identify supporting safety data (e.g. QSAR, HoSU) Evaluate required vs. available support Conduct risk assessment for each critical endpoint Conduct toxicology testing as required Overall safety evaluation for product – define acceptability and risk management measures

Available Non-animal Alternatives

Window Receptor solution in Receptor solution

• ut

Donor chamber Receptor chamber Skin position

OECD TG428 OECD TG471

OECD TG473 OECD TG476

OECD TG430/431 OECD TG439

OECD TG437 OECD TG438

10 20 30 40 50 60 70 80 90 100 110 120 0.1 1 10 100 1000 10000 % control NRU Concentration mg/ml EC50 level

OECD TG432

Eye Irritation Skin Corrosion/Irritation Phototoxicity Genotoxicity Skin Penetration

Current Scientific Reality: Non-animal Approaches For Safety Decisions

Human Health Toxicology Endpoint Timeline for Replacement of Animal Testing

[Note: Regulatory Acceptance would require an additional 4-8 years]

Comments Repeated dose toxicity No timeline for full replacement could be foreseen

Ongoing work still at research stage

Carcinogenicity No timeline for full replacement could be foreseen

Current in vitro test methods are inadequate for generating the dose- response information required for safety assessment

Skin Sensitisation 2017 – 2019 for full replacement

Several non-animal test methods under development & evaluation; data integration approaches for safety assessment required

Reproductive Toxicity No timeline for full replacement could be foreseen

Ongoing work still at research stage >2020 to identify key biological pathways

Toxicokinetics No timeline for full replacement could be foreseen

Ongoing work still at research stage 2015 – 2017: prediction of renal & biliary excretion and lung absorption

Adler et al (2011), Archives in Toxicology, 85 (5) 367-485

New Approaches to Risk Assessment Without Animals

» focus on non-animal approaches for consumer safety risk assessment » data required for safety decision should be driver » dose response information is essential » understanding the underpinning human biology » we are not looking for a way to do the animal test without the animal

US NRC Report June 2007

“Advances in toxicogenomics, bioinformatics, systems biology, epigenetics, and computational toxicology could transform toxicity testing from a system based on whole-animal testing to one founded primarily on in vitro methods that evaluate changes in biologic processes using cells, cell lines, or cellular components, preferably of human origin.”

Perturbation of Toxicity Pathways

Biologic Inputs

Normal Biologic Function

Adaptive Stress Responses

Early Cellular Changes Exposure Tissue Dose Biologic Interaction Perturbation

Low Dose Higher Dose Morbidity and Mortality

Cell Injury

Higher yet (From Andersen & Krewski, 2009, Tox Sci, 107, 324)

Exposure & Consumer Use Assessment High-content information in vitro assays in human cells & models Dose-response assessments Computational models of the circuitry of the relevant toxicity pathways PBPK models supporting in vitro to in vivo extrapolations Risk assessment based on exposures below the levels of significant pathway perturbations

Chemistry-led alerts & in vitro screening

TT21C

Adverse Outcome Pathways (AOP)

• Proposal for a template and guidance on developing and assessing the

Completeness of Adverse Outcome Pathways

Adapted from OECD (2012)

Adverse Outcome Pathway (AOP)

• An adverse outcome pathway (AOP) is the sequence of

events from the chemical structure of a target chemical through the molecular initiating event to an in vivo outcome of interest.

• It is the ‘capture’ of the mechanistic processes that

initiate and progress through the levels of biology to give rise to toxicity in living organisms for given chemical toxins.

• Each AOP represents the existing knowledge of the

linkage(s) between a molecular initiating event, intermediate events and an adverse outcome at the individual or population level.

Research on Animal Alternatives in India

Research on Animal Alternatives in India

Research on Animal Alternatives in India

Identification of Drosophila-based endpoints for the assessment and understanding of xenobiotic-mediated male reproductive adversities. Misra S, Singh A, Sharma V, Reddy Mudiam MK, Ram KR. Toxicol Sci. 2014 Sep;141(1):278-91. Invertebrate Alternatives for Toxicity Testing: Hydra Stakes its Claim Vidya Patwardhan and Surendra Ghaskadbi ALTEX Proceedings 2, 1/13, Proceedings of Animal Alternatives in Teaching, Toxicity Testing and Medicine Environmental chemical mediated male reproductive toxicity: Drosophila melanogaster as an alternate animal model A.K. Tiwari, P. Pragya, K. Ravi Rama, D. Kar Chowdhuri Theriogenology 76 (2011) 197–216

Oxidative stress as a classical case study for Adaptive responses

Biological Inputs

Normal Biological Function

Adverse Health Outcomes

Cell Dysfunction

Adaptive Stress Responses and Homeostasis

Altered Cellular Responses

Exposure Tissue Dose Biological Interaction Perturbation

An existing biochemical circuit in the cell that, when sufficiently perturbed, is expected to result in an adverse health effect. Adapted from Toxicity Testing in the 21st Century: A Vision and a Strategy, the U.S. National Academy of Sciences

Oxidative stress AOP understanding complex interactions

Modified network of oxidative stress as depicted by sbv improver. https://sbvimprover.com/

• The aim is to create an oxidative stress homeostasis model to

enable chemical risk assessment

 The mathematical model should captures the key pathways and

events involved in oxidative stress pathways, including in particular Nrf2.

 The model output should enumerate the key events that lead to

the adverse effects of oxidative stress and suggest the decision points for adaptive /adverse threshold.

 The model should provide the mechanistic understanding of the

underlying biology of oxidative stress due to the chemicals and explain any areas of uncertainty

Development of oxidative stress homeostasis model

Input: Assay data Output: Critical pathways Mechanism of toxicity Altered Redox Potential Apoptosis, Necrosis, Proliferation, Differentiation, Inflammation, ROS Cellular Antioxidants Repair Removal Downstream damage

Chemical

Nrf2 Pathway

Homeostasis

• Can it represent normal physiology?

Effect of drugs and toxins

• Can one simulate the effect of different (environmental) insults

to the liver?

• The output from this work can feed into an AOP-based approach

to understanding the risks associated with oxidative damage in the context of exposure-driven consumer safety risk assessments

Model output

Research on Animal Alternatives in India: Future Directions

• Learn from the experience we have from many years of research

that has been carried out in the EU on animal alternatives.

• Need to develop a roadmap and academia and STOX can help.
• Academia – Industry, Industry-Industry and Government /

Regulatory- Industry partnerships are critical in addressing this issue.

• There is a need to build capability built and upgrade skills especially

in areas of modelling.

• Training in toxicology is not enough; experts from various disciplines

need to work together in developing novel methodologies for risk assessment.

Challenges for the Future

• 1. Maximise use of existing validated non-animal methods for

safety decision-making (e.g. skin irritation, skin penetration etc.)

• 2. For those areas of toxicology where there are currently no

accepted alternatives to using animal studies, continue to develop new risk-based approaches for consumer safety assessment linked to understanding toxicity pathways

• 3. Importance of collaborative multi-disciplinary research to

generate new ideas, working with the best scientists globally

Thank you