Toxins

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Toxicology Fundamentals
Raman Govindarajan, MD, PhD. Regional Director
Medical and Scientific Affairs Johnson and
Johnson Asia Pacific
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A Day in Toxicology

• The Fundamentals of Toxicology
• Preclinical Safety Assessment of
  Cosmetics Toiletries
• How? Case Studies

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Toxicology Fundamentals

• What is Toxicology?
• The traditional definition of toxicology
• " the science of toxin .

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Toxicology Fundamentals

• What is Toxicology?
• A more descriptive definition of toxicology
• "the study of the adverse effects of chemicals or
  physical agents on living organisms".

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Toxicology Fundamentals

• Which one of the following is a toxin?
• 1. Alcohol
• 2. Aspirin
• 3. Water
• 4. Table salt

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Toxicology Fundamentals

• Toxicity depends on the DOSE

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Toxicology Fundamentals

• All substances are poisons there is none which
  is not a poison. The right dose differentiates a
  poison and a remedy.
• -- Paracelsus

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Toxicology Fundamentals

• Toxicity depends on the dose
• High oxygen level cause oxygen intoxication

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Toxicology Fundamentals

• Toxicity depends on the dose
• High oxygen level cause oxygen intoxication
• Too much water (several gallons) can cause
  osmotic imbalance and brain damage

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Toxicology Fundamentals

• Toxicity depends on the dose
• High oxygen level cause oxygen intoxication
• Too much water (several gallons) can cause
  osmotic imbalance and brain damage
• 1 beer vs. a six pack of beer

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Toxicology Fundamentals

• Toxicity depends on the dose
• High oxygen level cause oxygen intoxication
• Too much water (several gallons) can cause
  osmotic imbalance and brain damage
• 1 beer vs. a six pack of beer
• 1 sleeping pill vs. a bottle of sleeping pills

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Toxicology Fundamentals

• Toxicity depends on the dose
• High oxygen level cause oxygen intoxication
• Too much water (several gallons) can cause
  osmotic imbalance and brain damage
• 1 beer vs. a six pack of beer
• 1 sleeping pill vs. a bottle of sleeping pills
• 1 aspirin vs. a bottle of aspirins

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Toxicology Fundamentals

• What is LD 50 ?
• 1. Fifty Lead molecules
• 2. A famous singer in 1950s
• 3. A Latin dance introduced in 1950s
• 4. A means to measure toxicity

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Toxicology Fundamentals

• How is Toxicity measured by?

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Toxicology Fundamentals

• Toxicity is measured by LD50
• Lethal Dose that kills
• 50 of the population

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Toxicology Fundamentals

• Toxicity is measured by
• LD50 Lethal Dose that kills 50 of the
  population
• Dosage measured in weight of toxin per body
  weight

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Toxicology Fundamentals

• Dose-response curves are used to derive dose
  estimates of chemical substances. A common dose
  estimate for acute toxicity is the LD50 (Lethal
  Dose 50).

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Toxicology Fundamentals

• Examples of LD50
• Chemical LD50 (ppm)
• Nicotine 1
• DDT 100
• Table Salt 3000
• Trichloroethylene 5000

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Toxicology Fundamentals

• What is ED 10 ?
• 1. The 10th version of ET movie
• 2. Brief for the 10th Edward in the family
• 3. The 10th Executive Director in a company
• 4. Indication of the effectiveness of a
  substance

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Toxicology Fundamentals

• Effective Doses (EDs) are used to indicate the
  effectiveness of a substance. Normally,
  effective dose refers to a beneficial effect
  (relief of pain). It might also stand for a
  harmful effect (paralysis). Thus the specific
  endpoint must be indicated.

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Toxicology Fundamentals

• Effective Dose

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Toxicology Fundamentals

• What does EC stands for?
• 1. Title for a TV show starring a talking horse
• 2. Effective concentration
• 3. Exposure concentration
• 4. New musical show in Broadway

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Toxicology Fundamentals

• EC10
• This is the commonly used abbreviation for the
  exposure concentration of a toxicant causing a
  defined effect on 10 of a test population

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Toxicology Fundamentals

• Absorption is the process whereby a substance
  moves from outside the body into the body.

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Toxicology Fundamentals
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Toxicology Fundamentals

• Definition

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Toxicology Fundamentals

• What is Toxicokinetics?
• Toxicokinetics is the study of "how a substance
  gets into the body and what happens to it in the
  body".
• Essentially, it is the study of the kinetics of
  all toxic substances.

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Toxicology Fundamentals

• Toxicity/Preclinical Safety Review
• Single Dose Study
• Multiple Dose Study Subacute,
  Subchronic, Chronic
• Mutagenicity/Carcinogenicity Study

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Toxicology Fundamentals

• Acute toxicity results from a single exposure
  to a poisonous substance.
• Route of administration
• Oral, IV, IP, Dermal, Subcutaneous

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Toxicology Fundamentals

• Acute toxicity results from a single exposure
  to a poisonous substance
• Usually has an immediate life-threatening effect

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Toxicology Fundamentals

• Acute toxicity results from a single exposure
  to a poisonous substance
• Usually has an immediate life-threatening effect
• Usually easily diagnosed

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Toxicology Fundamentals

• Acute toxicity results from a single exposure
  to a poisonous substance
• Usually has an immediate life-threatening effect
• Usually easily diagnosed
• Most of the time there are antidotes that can
  reduce the toxicity of the chemical

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Toxicology Fundamentals

• Multiple Dose Tests
• Subacute days to 2 wks
• Subchronic 4 - 13 wks
• Chronic 6 - 12 months in rodents
• 7 - 10 years in non-rodents
• Study design depending on the objective of the
  study

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Toxicology Fundamentals

• Chronic toxicity results from prolonged
  exposure to a poisonous substance over a long
  period of time

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Toxicology Fundamentals

• Chronic toxicity results from prolonged
  exposure to a poisonous substance over a long
  period of time
• No immediate effect but could be life-threatening
  in the long term

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Toxicology Fundamentals

• Chronic toxicity results from prolonged
  exposure to a poisonous substance over a long
  period of time
• No immediate effect but could be life-threatening
  in the long term
• Usually hard to diagnose and treat

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Toxicology Fundamentals

• Chronic toxicity results from prolonged
  exposure to a poisonous substance over a long
  period of time
• No immediate effect but could be life-threatening
  in the long term
• Usually hard to diagnose and treat
• Hard to distinguish effects from other influences

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Toxicology Fundamentals

• What is mutagenic?
• 1. Something to do with music
• 2. Something to do with DNA
• 3. Something to do with mutes

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Toxicology Fundamentals

• Mutagenesis
• The process whereby a substance damages DNA and
  produces alterations in or loss of genes or
  chromosomes.

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Toxicology Fundamentals

• Mutagenicity Tests
• Ames Test
• Mammalian Chromosomal Aberration
• Micronucleus Test (in vivo)

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Toxicology Fundamentals

• What is carcinogenic ?
• 1. A place that makes cars
• 2. Something to do with gambling
• 3. Something that can cause tumors
• 4. A place that repairs cars

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Toxicology Fundamentals

• Carcinogen
• A carcinogen is any substance which causes
  cancer

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Toxicology Fundamentals

• Carcinogenicity Studies
• Traditional 2-year Bioassay
• different routes of administration, use rats and
  mice
• two year duration, expensive, labor-intensive
• interspecies extrapolation problem, especially
  mice

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Toxicology Fundamentals

• Carcinogenicity Studies
• Traditional Testing
• different routes of administration, use rats and
  mice
• two year duration, expensive, labor-intensive
• interspecies extrapolation problem, especially
  mice
• Transgenic Animal Testing
• P53, Neonatal, TgAc, XPA, XPA/P53 and RasH2
  models
• shorter testing period, less expensive, less
  labor-intensive
• have genes relevant to humans
• predictability? -- not enough data

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Toxicology Fundamentals

• What is a reproductive toxin?

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Toxicology Basic

• Reproductive toxicity is defined as adverse
  effects on the male and female reproductive
  systems that result from exposure to chemical
  substances.

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Toxicology Fundamentals

• Which of the following causes reproductive
  toxicity?
• 1. Alcohol
• 2. Vitamin A
• 3. Tobacco smoke (primary)
• 4. Aspirin

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Toxicology Fundamentals

• Special Toxicity Studies
• Eye Irritation
• Skin Irritation
• Contact Sensitization
• Comedogenicity
• Genital/Mucus Membrane Irritation

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Toxicology Fundamentals

• Irritation
• Any substance causing inflammation following
  immediate, prolonged, or repeated contact with
  skin or mucous membrane.

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Toxicology Fundamentals

• The most common cause of Occupational Skin
  Disease is irritation of the skin from contact
  with substances at work.

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Toxicology Fundamentals

• Strong irritants (e.g. acids, alkaline or
  solvents) cause skin inflammation after a short
  period of skin contact.

Dermatitis from cement
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Toxicology Fundamentals

• Weak irritants (such as water, detergents,
  coolants) cause inflammation after repeated
  exposures over a longer time.

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Toxicology Fundamentals

• Dermal Irritation Tests
• Primary Irritation Test
• Single Dose
• Cumulative Irritation Test
• Multiple Dose

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Toxicology Fundamentals

• In intracutaneous irritation tests using albino
  rabbits, the raised blebs caused by injecting
  extracts of test materials are either resolved
  without causing any visible changes or produce
  inflammation marked by redness and swelling in
  the 24 to 72 hours following injection.

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Toxicology Fundamentals

• Sensitization or hypersensitivity reactions
  usually occur as a result
• of repeated or prolonged contact
• with a substance that interacts
• with the body's immune system.

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Toxicology Fundamentals

• Which of the following is considered
• to be a sensitizer?
• 1. Latex Gloves
• 2. DNCB (1-chloro-2, 4-dinitrobenzene)
• 3. KathonCG
• 4. All of the above

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Toxicology Fundamentals

• After wearing natural latex gloves daily for
  several weeks or months, a person may develop a
  rash

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Toxicology Fundamentals

• Biomaterials and devices that cause
  sensitization reactions do so by means of their
  extractable chemical caused cell-mediated
  immunity.

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Toxicology Fundamentals

• Commonly Used Sensitization Tests
• Guinea Pig Maximization Test
• (Magnuson-Kligman Test)
• Modified Buhlers Test
• Local Lymph Node Assay

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Toxicology Fundamentals

• Positive response to DNCB in a guinea pig, seen
  in the maximization test

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Toxicology Fundamentals

• What does following compounds have in common?
• 1. Polycyclic aromatic hyrocarbons
• 2. Quinolones
• 3. Tetracyclines
• 4. PABA

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Toxicology Fundamentals

• Ingredients absorb in the solar spectrum (280 -
  400 nm)
• Photomutagenicity
• Phototoxicity
• Photosensitization
• Photocarcinogenicity

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Toxicology Fundamentals

• Studies to support Product Claims

• Ocular Irritation (Draize or TEP)
• Genital/Mucus Membrane Irritation
• Comedogenicity
• HET CAM eye irritation test

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Toxicology Fundamentals

• What is comedone?

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• Comedone
• A follicle that has been plugged with a
  combination of hardened oil (sebaceous material)
  and dead skin cells.

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Toxicology Fundamentals

• Which of the following can causes a
  comedogenic reaction?
• 1. Cocoa Butter
• 2. Lanolin
• 3. Amydimethyl PABA
• 4. All of the above

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Toxicology Fundamentals

• 1. Cocoa Butter - a skin softener and
  lubricator. It is considered comedogenic and may
  cause allergic reactions.
• 2. Lanolin - a sheeps wool derivative, it is
  highly comedogenic.
• Amyldimethyl PABA - causes skin irritation.
• All of the above

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Toxicology Fundamentals
Other important information

• Skin Absorption Data
• Toxicokinetic and Pharmacokinetic Data

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Toxicology Fundamentals

• Photosensitization
• Hypersensitivity to light.
• An abnormally heightened response, especially of
  the skin, to sunlight or ultraviolet radiation,
  caused by certain disorders or chemicals and
  characterized by a toxic or allergic reaction

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Toxicology Fundamentals

• Safety Testing
• Knowledge of Toxicity is primarily obtained in 3
  ways
• by studies using cells (in vitro)
• by experimental studies using animals
• by the study and observation of people during
  normal use of a substance

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Toxicology Fundamentals

• Four basic steps in the risk assessment process

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Toxicology Fundamentals
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Toxicology quiz

• What is toxicologist?
• 1. A person who always kills my project
• 2. A person who is intoxicated
• 3. A person who can not make it to medical
  school
• 4. Our partner in RD

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Toxicology Fundamentals

• Formulator and Toxicologist works together
• faster time to market !

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Toxicology Fundamentals
New Formulation
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Toxicology Fundamentals
New Formulation
Toxicology Testing
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Toxicology Fundamentals
New Formulation
Toxicology Testing
To Market
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Toxicology Fundamentals
New Formulation
Toxicology Testing
To Market