Dermal irritation and Corrosion test guidelines 204.
Dermal irritation is the production of reversible damage of the skin following the application of a test chemical for up to 4 hours.
Corrosive reactions are typified by ulcers, bleeding, bloody scabs, and, by the end of observation at 14 days, by discolouration due to blanching of the skin, complete areas of alopecia, and scars. Histopathology should be considered to evaluate questionable lesions. [1]
Dermal corrosion is the production of irreversible damage of the skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test chemical for up to four hours.[2]
REFERENCES
OECD/OCDE, Test No. 404: ‘‘Acute Dermal Irritation/Corrosion’’, 28 July 2015 OECD Publishing, peris, Page no, 1- 8.
Robert A., Turner., Screening Methods in Pharmacology; 1st edition; Academic press an imprint of Elsevier, pp, 279- 281.
OECD Guideline for testing of chemicals (1981). ‘‘Repeated Dose Dermal Toxicity’’, 21/28- day Study.
Regulatory guidelines for conducting toxicity studies by ichAnimatedWorld
ICH is the “International Conference on Harmonization of
Technical Requirements for Registration of Pharmaceuticals for
Human Use”
ICH is a joint initiative involving both regulators and research based industry representatives of the EU, Japan and the US in
scientific and technical discussions of the testing procedures required
to assess and ensure the safety, quality and efficacy of medicines
Toxicity is the science dealing with properties, action, toxicity, fatal dose detection or interpretation of result of toxicological analysis & treatment of poison.
Toxicity studies helps to avoid adverse effect and enhance the safety of drug.
This slide provides the information about toxicity screening on experimental animals.
Regulatory guidelines for conducting toxicity studies by ichAnimatedWorld
ICH is the “International Conference on Harmonization of
Technical Requirements for Registration of Pharmaceuticals for
Human Use”
ICH is a joint initiative involving both regulators and research based industry representatives of the EU, Japan and the US in
scientific and technical discussions of the testing procedures required
to assess and ensure the safety, quality and efficacy of medicines
Toxicity is the science dealing with properties, action, toxicity, fatal dose detection or interpretation of result of toxicological analysis & treatment of poison.
Toxicity studies helps to avoid adverse effect and enhance the safety of drug.
This slide provides the information about toxicity screening on experimental animals.
Acute eye irritation test as per OECD guidelinesmadhvi Chaubey
toxicological testing studies as per OECD guidline.
Toxicology is the branch of biology, chemistry and medicine concerned with the study of the adverse effects of chemicals on living organisms.
As per OECD test no. 405 : acute eye irritation test should be done as according to the procedure mentioned under guideline's section.
Alternative methods to animals testing are the development and implementation of test method that avoid use of live animals or use of less animals in method.
The council directive on protection of animals used for experiments and scientific purpose in article 23
“The commission and member states should encourage
research into development and validation of alternative methods which could provide the same level of information as that obtained in experiment using animals but which involves less animal”.
Alternative methods able to do:
Reduce Refine Replace
collectively called as “The 3Rs Principle”.
Needs for alternative methods
Because in laboratory animals may be:
Poisoned.
Deprived of food water and sleep.
Applied with skin and eye irritants.
Subjected to psychological stress.
Deliberately infected with the infected disease.
This presentation provides an in-depth examination of dermal irritation and corrosion, focusing on the principles, testing methods, and safety measures involved. Participants will gain insight into the mechanisms underlying dermal irritation and corrosion, as well as the potential risks posed by various substances. Through a detailed exploration of testing protocols such as the Draize test and in vitro alternatives, attendees will learn how these assessments are conducted to ensure product safety and regulatory compliance. Join us to deepen your understanding of dermal irritation and corrosion, essential for ensuring the safety and well-being of consumers and workers alike.
Acute eye irritation test as per OECD guidelinesmadhvi Chaubey
toxicological testing studies as per OECD guidline.
Toxicology is the branch of biology, chemistry and medicine concerned with the study of the adverse effects of chemicals on living organisms.
As per OECD test no. 405 : acute eye irritation test should be done as according to the procedure mentioned under guideline's section.
Alternative methods to animals testing are the development and implementation of test method that avoid use of live animals or use of less animals in method.
The council directive on protection of animals used for experiments and scientific purpose in article 23
“The commission and member states should encourage
research into development and validation of alternative methods which could provide the same level of information as that obtained in experiment using animals but which involves less animal”.
Alternative methods able to do:
Reduce Refine Replace
collectively called as “The 3Rs Principle”.
Needs for alternative methods
Because in laboratory animals may be:
Poisoned.
Deprived of food water and sleep.
Applied with skin and eye irritants.
Subjected to psychological stress.
Deliberately infected with the infected disease.
This presentation provides an in-depth examination of dermal irritation and corrosion, focusing on the principles, testing methods, and safety measures involved. Participants will gain insight into the mechanisms underlying dermal irritation and corrosion, as well as the potential risks posed by various substances. Through a detailed exploration of testing protocols such as the Draize test and in vitro alternatives, attendees will learn how these assessments are conducted to ensure product safety and regulatory compliance. Join us to deepen your understanding of dermal irritation and corrosion, essential for ensuring the safety and well-being of consumers and workers alike.
Medical and Healthcare Professions:
Medical Doctors: Physiology forms the foundation for medical education. It is essential for diagnosing, treating, and preventing diseases. Doctors need a deep understanding of how the body's systems work to provide effective patient care.
Nurses: Nurses rely on physiology to monitor patients' vital signs, administer medications, and provide overall care. Understanding physiology is vital for patient safety.
Pharmacists: Pharmacists require knowledge of physiology to understand drug interactions, mechanisms of action, and potential side effects.
Biomedical Research:
Physiologists and researchers use knowledge of physiology to conduct experiments, develop new therapies, and advance medical science. This research is critical for discovering treatments for diseases.
Sports Science and Exercise Physiology:
Understanding how the body responds to exercise and physical activity is essential in sports science. Coaches, athletes, and fitness professionals rely on this knowledge to optimize training regimens and improve performance.
Nutrition and Dietetics:
Nutritionists and dietitians use physiology to understand how nutrients affect the body's various systems. This knowledge helps in designing diets to manage health conditions and promote overall well-being.
Pharmaceutical and Biotechnology Industries:
Professionals in these industries need to understand the physiological effects of drugs and biotechnological products to develop safe and effective treatments.
Biomechanics:
Physiological principles are fundamental in biomechanics, which is crucial in fields like orthopedics, physical therapy, and engineering to design prosthetics and improve mobility.
Environmental Science:
Environmental scientists study the physiological responses of organisms to changes in their environment, which is essential for understanding the impact of climate change and pollution on ecosystems.
Psychology and Neurobiology:
Understanding the physiological basis of behavior and cognition is critical in psychology and neuroscience. This knowledge helps in researching and treating mental health disorders.
Public Health:
Public health professionals need to comprehend the physiological aspects of disease transmission and prevention, especially in epidemiology and health policy development.
Education and Science Communication:
Educators and science communicators use physiology to teach students and the general public about the importance of health and wellness, disease prevention, and medical advancements.
Personal Well-Being:
Knowledge of physiology helps individuals make informed decisions about their health, leading to a healthier lifestyle, better disease prevention, and improved quality of life.
In summary, the study of physiology is a cornerstone of various disciplines and professions, impacting healthcare, research, sports, nutrition, industry, and more. It equips students with a deep understanding of how the human body functions, en
Skin sensitisation, OECD Test guideline 406 .pptxNikitaBankoti2
Skin Sensitisation: ( allergic contact dermatitis) is an immunologically mediated cutaneous reaction to a substance. In the human, the responses may be characterised by pruritis, erythema, oedema, papules, vesicles or a combination of these. In other species the reactions may differ and only erythema and oedema may be seen.
Dear Friends,
This is my 3rd presentation, which will help you to understand the depth knowledge of acute eye irritation/corrosion (OECD-405) study in rabbit.
R3 Stem Cells and Kidney Repair A New Horizon in Nephrology.pptxR3 Stem Cell
R3 Stem Cells and Kidney Repair: A New Horizon in Nephrology" explores groundbreaking advancements in the use of R3 stem cells for kidney disease treatment. This insightful piece delves into the potential of these cells to regenerate damaged kidney tissue, offering new hope for patients and reshaping the future of nephrology.
Deep Leg Vein Thrombosis (DVT): Meaning, Causes, Symptoms, Treatment, and Mor...The Lifesciences Magazine
Deep Leg Vein Thrombosis occurs when a blood clot forms in one or more of the deep veins in the legs. These clots can impede blood flow, leading to severe complications.
CRISPR-Cas9, a revolutionary gene-editing tool, holds immense potential to reshape medicine, agriculture, and our understanding of life. But like any powerful tool, it comes with ethical considerations.
Unveiling CRISPR: This naturally occurring bacterial defense system (crRNA & Cas9 protein) fights viruses. Scientists repurposed it for precise gene editing (correction, deletion, insertion) by targeting specific DNA sequences.
The Promise: CRISPR offers exciting possibilities:
Gene Therapy: Correcting genetic diseases like cystic fibrosis.
Agriculture: Engineering crops resistant to pests and harsh environments.
Research: Studying gene function to unlock new knowledge.
The Peril: Ethical concerns demand attention:
Off-target Effects: Unintended DNA edits can have unforeseen consequences.
Eugenics: Misusing CRISPR for designer babies raises social and ethical questions.
Equity: High costs could limit access to this potentially life-saving technology.
The Path Forward: Responsible development is crucial:
International Collaboration: Clear guidelines are needed for research and human trials.
Public Education: Open discussions ensure informed decisions about CRISPR.
Prioritize Safety and Ethics: Safety and ethical principles must be paramount.
CRISPR offers a powerful tool for a better future, but responsible development and addressing ethical concerns are essential. By prioritizing safety, fostering open dialogue, and ensuring equitable access, we can harness CRISPR's power for the benefit of all. (2998 characters)
Antibiotic Stewardship by Anushri Srivastava.pptxAnushriSrivastav
Stewardship is the act of taking good care of something.
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
WHO launched the Global Antimicrobial Resistance and Use Surveillance System (GLASS) in 2015 to fill knowledge gaps and inform strategies at all levels.
ACCORDING TO apic.org,
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
ACCORDING TO pewtrusts.org,
Antibiotic stewardship refers to efforts in doctors’ offices, hospitals, long term care facilities, and other health care settings to ensure that antibiotics are used only when necessary and appropriate
According to WHO,
Antimicrobial stewardship is a systematic approach to educate and support health care professionals to follow evidence-based guidelines for prescribing and administering antimicrobials
In 1996, John McGowan and Dale Gerding first applied the term antimicrobial stewardship, where they suggested a causal association between antimicrobial agent use and resistance. They also focused on the urgency of large-scale controlled trials of antimicrobial-use regulation employing sophisticated epidemiologic methods, molecular typing, and precise resistance mechanism analysis.
Antimicrobial Stewardship(AMS) refers to the optimal selection, dosing, and duration of antimicrobial treatment resulting in the best clinical outcome with minimal side effects to the patients and minimal impact on subsequent resistance.
According to the 2019 report, in the US, more than 2.8 million antibiotic-resistant infections occur each year, and more than 35000 people die. In addition to this, it also mentioned that 223,900 cases of Clostridoides difficile occurred in 2017, of which 12800 people died. The report did not include viruses or parasites
VISION
Being proactive
Supporting optimal animal and human health
Exploring ways to reduce overall use of antimicrobials
Using the drugs that prevent and treat disease by killing microscopic organisms in a responsible way
GOAL
to prevent the generation and spread of antimicrobial resistance (AMR). Doing so will preserve the effectiveness of these drugs in animals and humans for years to come.
being to preserve human and animal health and the effectiveness of antimicrobial medications.
to implement a multidisciplinary approach in assembling a stewardship team to include an infectious disease physician, a clinical pharmacist with infectious diseases training, infection preventionist, and a close collaboration with the staff in the clinical microbiology laboratory
to prevent antimicrobial overuse, misuse and abuse.
to minimize the developme
How many patients does case series should have In comparison to case reports.pdfpubrica101
Pubrica’s team of researchers and writers create scientific and medical research articles, which may be important resources for authors and practitioners. Pubrica medical writers assist you in creating and revising the introduction by alerting the reader to gaps in the chosen study subject. Our professionals understand the order in which the hypothesis topic is followed by the broad subject, the issue, and the backdrop.
https://pubrica.com/academy/case-study-or-series/how-many-patients-does-case-series-should-have-in-comparison-to-case-reports/
Global launch of the Healthy Ageing and Prevention Index 2nd wave – alongside...ILC- UK
The Healthy Ageing and Prevention Index is an online tool created by ILC that ranks countries on six metrics including, life span, health span, work span, income, environmental performance, and happiness. The Index helps us understand how well countries have adapted to longevity and inform decision makers on what must be done to maximise the economic benefits that comes with living well for longer.
Alongside the 77th World Health Assembly in Geneva on 28 May 2024, we launched the second version of our Index, allowing us to track progress and give new insights into what needs to be done to keep populations healthier for longer.
The speakers included:
Professor Orazio Schillaci, Minister of Health, Italy
Dr Hans Groth, Chairman of the Board, World Demographic & Ageing Forum
Professor Ilona Kickbusch, Founder and Chair, Global Health Centre, Geneva Graduate Institute and co-chair, World Health Summit Council
Dr Natasha Azzopardi Muscat, Director, Country Health Policies and Systems Division, World Health Organisation EURO
Dr Marta Lomazzi, Executive Manager, World Federation of Public Health Associations
Dr Shyam Bishen, Head, Centre for Health and Healthcare and Member of the Executive Committee, World Economic Forum
Dr Karin Tegmark Wisell, Director General, Public Health Agency of Sweden
The dimensions of healthcare quality refer to various attributes or aspects that define the standard of healthcare services. These dimensions are used to evaluate, measure, and improve the quality of care provided to patients. A comprehensive understanding of these dimensions ensures that healthcare systems can address various aspects of patient care effectively and holistically. Dimensions of Healthcare Quality and Performance of care include the following; Appropriateness, Availability, Competence, Continuity, Effectiveness, Efficiency, Efficacy, Prevention, Respect and Care, Safety as well as Timeliness.
Defecation
Normal defecation begins with movement in the left colon, moving stool toward the anus. When stool reaches the rectum, the distention causes relaxation of the internal sphincter and an awareness of the need to defecate. At the time of defecation, the external sphincter relaxes, and abdominal muscles contract, increasing intrarectal pressure and forcing the stool out
The Valsalva maneuver exerts pressure to expel faeces through a voluntary contraction of the abdominal muscles while maintaining forced expiration against a closed airway. Patients with cardiovascular disease, glaucoma, increased intracranial pressure, or a new surgical wound are at greater risk for cardiac dysrhythmias and elevated blood pressure with the Valsalva maneuver and need to avoid straining to pass the stool.
Normal defecation is painless, resulting in passage of soft, formed stool
CONSTIPATION
Constipation is a symptom, not a disease. Improper diet, reduced fluid intake, lack of exercise, and certain medications can cause constipation. For example, patients receiving opiates for pain after surgery often require a stool softener or laxative to prevent constipation. The signs of constipation include infrequent bowel movements (less than every 3 days), difficulty passing stools, excessive straining, inability to defecate at will, and hard feaces
IMPACTION
Fecal impaction results from unrelieved constipation. It is a collection of hardened feces wedged in the rectum that a person cannot expel. In cases of severe impaction the mass extends up into the sigmoid colon.
DIARRHEA
Diarrhea is an increase in the number of stools and the passage of liquid, unformed feces. It is associated with disorders affecting digestion, absorption, and secretion in the GI tract. Intestinal contents pass through the small and large intestine too quickly to allow for the usual absorption of fluid and nutrients. Irritation within the colon results in increased mucus secretion. As a result, feces become watery, and the patient is unable to control the urge to defecate. Normally an anal bag is safe and effective in long-term treatment of patients with fecal incontinence at home, in hospice, or in the hospital. Fecal incontinence is expensive and a potentially dangerous condition in terms of contamination and risk of skin ulceration
HEMORRHOIDS
Hemorrhoids are dilated, engorged veins in the lining of the rectum. They are either external or internal.
FLATULENCE
As gas accumulates in the lumen of the intestines, the bowel wall stretches and distends (flatulence). It is a common cause of abdominal fullness, pain, and cramping. Normally intestinal gas escapes through the mouth (belching) or the anus (passing of flatus)
FECAL INCONTINENCE
Fecal incontinence is the inability to control passage of feces and gas from the anus. Incontinence harms a patient’s body image
PREPARATION AND GIVING OF LAXATIVESACCORDING TO POTTER AND PERRY,
An enema is the instillation of a solution into the rectum and sig
1. SEMINAR ON –
DERMAL IRRITATION AND DERMAL TOXICITY
Subject: Pharmacological & Toxicological Screening method- II
A.R College of Pharmacy and G. H Patel Institute of Pharmacy
Vallabh Vidyanagar, Anand
Guided By
Ms. M. S. Saiyed
Assistant Professor
M. Pharm
Department of Pharmacology
Presented By
Dinesh M Gangoda
Class: M. Pharm (Sem-II)
Roll No- MPL04
2. CONTENTS
Dermal irritation
• Introduction
• Principle
• Preparation of the in vivo test
• Test Procedure( Methodology)
• Observation and Grading scores
Dermal Toxicity
• Introduction
• Principle
• Test Procedure
References
2
3. DERMAL IRRITATION
Introduction
Dermal irritation is the production of reversible damage of the skin following the
application of a test chemical for up to 4 hours.
Corrosive reactions are typified by ulcers, bleeding, bloody scabs, and, by the end
of observation at 14 days, by discolouration due to blanching of the skin,
complete areas of alopecia, and scars. Histopathology should be considered to
evaluate questionable lesions. [1]
Dermal corrosion is the production of irreversible damage of the skin; namely,
visible necrosis through the epidermis and into the dermis, following the
application of a test chemical for up to four hours.[2]
3
4. PRINCIPLE:
The test chemical to be tested is applied in a single dose to the skin of an
experimental animal; untreated skin areas of the test animal serve as the
control.
The degree of irritation/corrosion is read and scored at specified intervals and
is further described in order to provide a complete evaluation of the effects.
The duration of the study should be sufficient to evaluate the reversibility or
irreversibility of the effects observed.
Animals showing continuing signs of severe distress and/or pain at any stage
of the test should be humanely killed, and the test chemical assessed
accordingly.
Criteria for making the decision to humanely kill moribund and severely
suffering animals are the subject of a separate guidance document. [1]
4
5. PREPARATIONS FOR THE IN VIVO TEST
Selection of animal species:
The Albino Rabbit is the preferable
laboratory animal and healthy young
adult rabbits are used.
A rationale for using other species
should be provided.
Albino Rabbit
5
6. Approximately 24 hours before the test, for
should be removed by closely clipping the dorsal
area of the trunk of the animals.
Care should be taken to avoid abrading the skin,
and only animals with healthy, intact skin should
be used.
Some strains of rabbit have dense patches of hair
that are more prominent at certain times of the
year. Such areas of dense hair growth should not
be used as test sites.
Albino Rabbit
Cont..
6
7. Housing and feeding conditions:
Rabbit at least 12 weeks old and body weight 1.5 kg-3.0 kg.
The temperature should be 200C (± 30C) for rabbits.
Relative humidity should be at least 30% and preferably not exceed 70%, other than
during room cleaning; the aim should be 50-60%.
Lighting should be 12 hours light, 12 hours dark.
For feeding, conventional laboratory diets may be used with an unrestricted supply
of drinking water.
7
8. Rabbits are especially susceptible to the effects of stress and should always be
approached in a calm and confident manner.
The handler is restraining the rabbit firmly by the scruff with the other hand
ready to support the animal’s hindquarters.
There is no one correct method of handling or restraining animals, but the
general principle is that it should not cause pain or discomfort to the animal. It
should also be comfortable for the handler.
HANDLING AND RESTRAINT
8
10. Dose level
A dose of 0.5 mL of liquid or 0.5 g of solid or paste is applied to the test site.
Application of the test chemical:
The test chemical should be applied to a dorsal/flank region (approximately 6 cm
2) of skin and covered with a gauze patch, which is held in place with non-
irritating tape.
In cases in which direct application is not possible (e.g., liquids or some pastes),
the test chemical should first be applied to the gauze patch, which is then applied
to the skin.
The patch should be loosely held in contact with the skin by means of a suitable
semi-occlusive dressing for the duration of the exposure period.
TEST PROCEDURE[1]
10
12. CONT..
If the test chemical is applied to the patch, it should be attached to the skin in
such a manner that there is good contact and uniform distribution of the test
chemical on the skin.
Access by the animal to the patch and ingestion or inhalation of the test chemical
should be prevented.
Liquid test chemicals are generally used undiluted.
When testing solids (which may be pulverised, if considered necessary), the test
chemical should be moistened with the smallest amount of water (or, where
necessary, of another suitable vehicle) sufficient to ensure good skin contact.
12
13. CONT..
When vehicles other than water are used, the potential influence of the vehicle on
irritation of the skin by the test chemical should be minimal, if any.
At the end of the exposure period, which is normally 4 hours, residual test
chemical should be removed, where practicable, using water or an appropriate
solvent without altering the existing response or the integrity of the epidermis.[3]
13
14. INITIAL TEST (USING ONE ANIMAL)[1]
When a test chemical has been judged to be corrosive, irritant or non-classified on the
basis of a weight of evidence analyses or of previous in vitro testing, further in vivo
testing is normally not necessary.
However, in the cases where additional data are felt warranted, the in vivo test is
performed initially using one animal and applying the following approach.
Up to three test patches are applied sequentially to the animal. The first patch is
removed after three minutes.
14
15. If no serious skin reaction is observed, a second patch is applied at a different
site and removed after one hour.
If the observations at this stage indicate that exposure can humanely be
allowed to extend to four hours, a third patch is applied and removed after
four hours, and the response is graded.
15
16. CONT..
If a corrosive effect is observed after any of the three sequential exposures, the test is
immediately terminated.
If a corrosive effect is not observed after the last patch is removed, the animal is
observed for 14 days, unless corrosion develops at an earlier time point.
In those case in which the test chemical is not expected to produce corrosion but may
be irritating, a single patch should be applied to one animal for four hours.
16
17. CONFIRMATORY TEST (WITH ADDITIONAL ANIMALS)
If a corrosive effect is not observed in the initial test, the irritant or negative
response should be confirmed using up to two additional animals, each with one
patch, for an exposure period of four hours.
If an irritant effect is observed in the initial test, the confirmatory test may be
conducted in a sequential manner, or by exposing two additional animals
simultaneously.
17
18. In the exceptional case, in which the initial test is not conducted, two or three
animals may be treated with a single patch, which is removed after four hours.
When two animals are used, if both exhibit the same response, no further testing
is needed. Otherwise, the third animal is also tested.
Equivocal responses may need to be evaluated using additional animals.
18
19. OBSERVATION PERIOD
The duration of the observation period should be sufficient to evaluate fully the
reversibility of the effects observed.
The experiment should be terminated at any time that the animal shows
continuing signs of severe pain or distress.
To determine the reversibility of effects, the animals should be observed up to 14
days after removal of the patches.
If reversibility is seen before 14 days, the experiment should be terminated at that
time.
19
20. CLINICAL OBSERVATIONS AND GRADING OF SKIN REACTIONS:
All animals should be examined for signs of erythema and oedema, and the
responses scored at 60 minutes, and then at 24, 48 and 72 hours after patch
removal.
For the initial test in one animal, the test site is also examined immediately after
the patch has been removed.
If there is damage to skin which cannot be identified as irritation or corrosion at 72
hours, observations may be needed until day 14 to determine the reversibility of the
effects.
In addition to the observation of irritation, all local toxic effects, such as defatting
of the skin, and any systemic adverse effects (e.g., effects on clinical signs of
toxicity and body weight), should be fully described and recorded.
20
21. Erythema and Eschar Formation Grades
No erythema 0
Very slight erythema (barely perceptible) 1
Well defined erythema 2
Moderate to severe erythema 3
Severe erythema (beef redness) to eschar
formation preventing grading of erythema
4
Maximum possible: 4
TABLE: GRADING OF SKIN REACTIONS [1]
Erythema and Eschar Formation
21
23. Oedema Formation Grades
No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well defined by
definite raising)
2
Moderate oedema (raised approximately 1 mm) 3
Severe oedema (raised more than 1mm and
extending beyond area of exposure)
4
Maximum possible: 4
Oedema Formation [1]
23
24. DERMAL TOXICITY STUDIES
Introduction
Dermal toxicity involves the assessment and evaluation of the toxic
characteristics of a substance. It is useful where the exposure to dermal route is
likely. [3]
24
25. Principle:
• The test substance is applied to the skin in graduated doses to several groups of
experimental animals.
• Animals which die during the test are necropsied and surviving animals are also
done the same at the conclusion.
• Animals showing severe and enduring sings of distress and pain may need to be
humanely killed.
25
26. Requirements:
Selection of species: Albino Rabbit
Body weight:
• Rabbit- 1.5 to 3.0 gm
Age:
• Rabbit- at least 12 weeks old
Sex:
• Male/ female
Dose: 200mg/kg
Figure: Albino Rabbit 26
27. Preparation of test item;
Solid- Moistened with distilled water/vehicle
Liquids- applied directly without dilution.
Preparation of test animals:
One day before application of the items, 10% of the total body surface area of the
animals will be clipped with electric clipper/ shaved with razor blade/ depilated
with VEET cream.
The position of clipping will be the area starting at the scapulae(shoulders) to
wring of the ilium (hipbone) and half way down the flunk on each side.
27
28. Test material should be applied on shaved skin covering not less than 10% of the
total body surface area.
Porous gauze dressing should be used to hold liquid material in place.
Formulations with different concentrations (at least 3) of test substance, several
fold higher than the clinical dosage form should be used.
Test Procedure
28
29. Period of application may vary from 7 to 90 days depending on the clinical duration
of use.
Where skin irritation is grossly visible in the initial studies, a recovery group should
be included in the subsequent repeated study.
Local signs (erythema, oedema and Escher formation) as well as histopathological
examination of sites of application should be used for evaluation of results.
29