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Evaluation of the Dermal Irritancy of Chemicals
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
Various researchers have suggested modifications to the Draize test as originally proposed. Most suggested modifications deal with choice of animal species, site of application, duration of exposure, deletion of abraded skin testing, the use of occlusive or semiocclusive dressings, the time of scoring of lesions, the procedures to use when testing solid substances, i.e., to moisten or dissolve or apply as a solid, and the use of solvent or negative, and known positive control substances. There have been recommendations to use repeat application testing with animals, as is done in man.12,32,33 Repeated testing may demonstrate the production of irritation by mild irritants, but rather than due strictly to a true contact dermatitis, there may be immunologically mediated responses. The precise reasons for the irritation, however, may be of little concern to the consumer. The same immunologically mediated response could be possible in research animals if they have been previously exposed to a test compound or one of its components.
Models of Toxicity Screening Using Cultured Cells
Published in John J. Lemasters, Constance Oliver, Cell Biology of Trauma, 2020
Roberta L. Grant, Daniel Acosta
Substances that cause damage to the eye have traditionally been assessed by in vivo means such as the Draize rabbit eye test. The Draize test consists of placing 0.1 ml or 0.1 g of test compound into the cul-de-sac of the rabbit’s eye, observing the damage to the cornea, conjunctiva, and iris, and assigning a numerical score to the amount of damage that results. Because of the importance of the cornea to vision, 73% of the total Draize score is based on corneal damage. This test is a whole-animal model and a wealth of information can be obtained from it. Observations occur over different time intervals so that initial damage, as well as reversibility of injury, may be assessed.
Animal Toxicity Studies
Published in Nicola Loprieno, Alternative Methodologies for the Safety Evaluation of Chemicals in the Cosmetic Industry, 2019
A contact with chemicals as a consequence of an accident, or a normal contact with chemicals present in cosmetic products employed for human skin care, may produce ocular damages. The method to evaluate qualitative alterations produced in the eyes of exposed animals and to transform them into quantitative measurements is known as the Draize test. According to this method, the substance to be tested is applied in a single dose to one eye in each of several experimental animals (the species recommended is the adult albino rabbit); the untreated eye is used to provide control information. The degree of irritation is evaluated and graded at specific intervals, and it is further described to provide a complete evaluation of the effects. The duration of observations should be sufficient to evaluate fully either reversibility or irreversibility of the effects observed. In addition to the observations of the cornea, iris, and conjunctiva, any other lesions that are noted should be recorded and reported.
Fabrication of nanostructured lipid carriers ocugel for enhancing Loratadine used in treatment of COVID-19 related symptoms: statistical optimization, in-vitro, ex-vivo, and in-vivo studies evaluation
Published in Drug Delivery, 2022
Rehab Abdelmonem, Inas Essam Ibrahim Al-Samadi, Rasha M. El Nashar, Bhaskara R. Jasti, Mohamed A. El-Nabarawi
In vivo monitoring of ocular irritation was determined by classical Draize test of optimized LORA-NLCs Ocugel. Four adults, white New Zealand male albino rabbits each one balancing 2–3 kg, were stable and had no abnormalities. The standard conditions such as moisture, air, temperature, and light, in addition to food, and water were maintained. The formula was installed in the left eye particular in the conjunctival sac, as well as the right eye was reserved as control by applying saline at intervals 0, 1, 2, 3, 4, 5, 6, 24, 48, and finally at 72 hours then 7, 14, and 21 days after installation, each eye of rabbit was examined to assess the irritation grade. Draize test applies a scoring system varying from 0 (no irritation) to 3 (maximum redness and irritation) in the iris, cornea, conjunctiva, and pupil, in addition to the anterior chamber. At the end of the experiment eyeballs of the rabbits instantaneously were taken out for further histopathological studies (El-Emam et al., 2021).
Proniosomal gel-derived niosomes: an approach to sustain and improve the ocular delivery of brimonidine tartrate; formulation, in-vitro characterization, and in-vivo pharmacodynamic study
Published in Drug Delivery, 2019
Alaa Emad Eldeeb, Salwa Salah, Mahmoud Ghorab
Draize test is the most reliable test for determination of ocular irritation of prepared formulations (Draize et al., 1944). Seven New Zealand male albino rabbits were subjected to the administration of the optimized formula and the market eye drops in order to evaluate the irritancy of both (Shivakumar et al., 2007). Draize test depends on scoring system ranging from 0 (no irritation) to +3 (highest irritation and redness) for the cornea, iris, and conjunctivae. The tested formulation was applied in the conjunctival sac of the right eye and the left eye was kept as control by instillation of saline. The cornea, iris, and conjunctivae were examined for any signs of irritation or congestion caused by the formulation. Testing the ocular irritation score was done at intervals of 1, 2, 5, 8, and 24 h after administration (Tayel et al., 2013; Shokry et al., 2018).
In vitro skin irritation assessment using EpiDerm™: applicability for updating toxicity information of oxybenzone and N,N-diethyl-m-toluamide
Published in Drug and Chemical Toxicology, 2020
Ji-Seok Han, Yong-Bum Kim, Heejin Park, Wan-Jung Im, Woo-Jin Kim, Younhee Kim, Joo-Yun Won, Hwa-Young Son, Byoung-Seok Lee
The skin constitutes the largest organ and part of the body, and it contacts various foreign materials such as compounds, pharmaceuticals, and cosmetic products either accidentally or intentionally. To predict the human skin irritation potential of substances, the rabbit Draize test has been used traditionally for approximately 60 years and was considered the gold standard for risk assessment of the skin and eyes (Draize et al.1944). However, concerns about animal welfare and unnecessary use of animals have been steadily increasing for decades with the increasing demand for more effective and accurate assays representing the human skin at early exploration. These concerns have promoted the development of alternative methods to investigate skin irritancy (Lee et al.2000, Ghosh and Blankschtein 2007). Recently, 3D reconstructed human epidermal (RhE) models have been increasing used to evaluate skin toxicity and pharmacology as an alternative to animal testing (Danilenko et al.2016). These models consist of three viable layers of the stratum basale, stratum spinosum, and stratum granulosum and one non-viable layer of stratum corneum, and they have some strong advantages such as good reproducibility and predictability and quick compound screening (Faller et al.2002, Netzlaff et al.2005). According to Organization for Economic Cooperation and Development (2015) Test Guideline (OECD TG) 439, four types (EpiSkin™, EpiDerm™ SIT, SkinEthic™ RhE, and LabCyte EPI-MODEL24 SIT) of RhE models have currently been approved for skin irritation testing, and test chemicals are considered as nonirritant to skin if the tissue viability after exposure is more than 50%.