Evaluation of seven alternative assays on the main ingredients in cosmetics as predictors of Draize eye irritation scores

Corneal epithelium models for safety assessment in drug development: Present and future directions

The human corneal epithelial barrier plays a crucial role in drug testing studies, including drug absorption, distribution, metabolism, and excretion (ADME), as well as toxicity testing during the preclinical stages of drug development. However, despite the valuable insights gained from animal and current in vitro models, there remains a significant discrepancy between preclinical drug predictions and actual clinical outcomes. Additionally, there is a growing emphasis on adhering to the 3R principles (refine, reduce, replace) to minimize the use of animals in testing. To tackle these challenges, there is a rising demand for alternative in vitro models that closely mimic the human corneal epithelium. Recently, remarkable advancements have been made in two key areas: microphysiological systems (MPS) or organs-on-chips (OoCs), and stem cell-derived organoids. These cutting-edge platforms integrate four major disciplines: stem cells, microfluidics, bioprinting, and biosensing technologies. This integration holds great promise in developing powerful and biomimetic models of the human cornea.

Safety Assessment of Saccharide Esters as Used in Cosmetics

This is a safety assessment of 40 saccharide ester ingredients as used in cosmetics. The saccharide esters are reported to function in cosmetics as emollients, skin-conditioning agents, fragrance ingredients, and emulsion stabilizers. The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the relevant data for these ingredients. The Panel concluded that the saccharide esters are safe in cosmetics in the present practices of use and concentrations described in this safety assessment.

The chick embryo chorioallantoic membrane model: a research approach for ex vivo and in vivo experiments

BACKGROUND

The chick chorioallantoic membrane (CAM) model has attracted a great deal of interest in pharmaceutical and biological research as an alternative or complementary in vivo assay to animal models. Traditionally, CAM assay has been widely used to perform some toxicological studies, specifically to evaluate the skin, ocular and embryo toxicity of new drugs and formulations, and perform angiogenesis studies. Due to the possibility to generate the tumors onto the CAM, this model has also become an excellent strategy to evaluate the metastatic potential of different tumours and test the efficacy of novel anticancer therapies in vivo. Moreover, in the recent years, its use has considerably grown in other research areas, including the evaluation of new anti-infective agents, the development of biodistribution studies and tissue engineering research.

OBJECTIVES

This manuscript provides a critical overview of the use of CAM model in pharmaceutical and biological research, especially to test the toxicity of new drugs and formulations and the biodistribution and the efficacy of novel anticancer and anti-infective therapies, analyzing its advantages and disadvantages compared to animal models.

CONCLUSION

The chick chorioallantoic membrane model shows great utility in several research areas, such as cancer, toxicology, biodistribution studies and anti-infective therapies. In fact, it has become an intermediate stage between in vitro experiments and animal studies, and, in the case of toxicological studies (skin and ocular toxicity), has even replaced the animal models.

Final Report on the Safety Assessment of Octoxynol-1, Octoxynol-3, Octoxynol-5, Octoxynol- 6, Octoxynol-7, Octoxynol-8, Octoxynol-9, Octoxynol-10, Octoxynol-11, Octoxynol-12, Octoxynol-13, Octoxynol-16, Octoxynol-20, Octoxynol-25, Octoxynol-30, Octoxynol-33, Octoxynol-40, Octoxynol-70, Octoxynol-9 Carboxylic Acid, Octoxynol-20 Carboxylic Acid, Potassium Octoxynol-12 Phosphate, Sodium Octoxynol-2 Ethane Sulfonate, Sodium Octoxynol-2 Sulfate, Sodium Octoxynol-6 Sulfate, and Sodium Octoxynol-9 Sulfate1

Octoxynols are ethoxylated alkylphenols in which the size of the molecule is related to the number of moles of ethylene oxide used in synthesis. Reactions are performed at elevated temperature, under pressure, and in the presence of NaOH. It is possible that the synthesis may leave trace amounts of ethylene oxide, 1,4-dioxane, and unreacted C9 phenols. Octoxynols of various chain lengths as well as octoxynol salts and organic acids function in cosmetics either as surfactants—emulsifying agents, surfactants—cleansing agents, surfactant—solubilizing agents, or surfactants—hydrotropes in a wide variety of cosmetic products at concentrations ranging from 0.0008% to 25%, with most less than 5.0%. The octoxynols are chemically similar to nonoxynols, the safety of which were previously considered. Long-chain nonoxynols (9 and above) were considered safe as used, whereas short-chain nonoxynols (8 and below) were considered safe as used in rinse-off products and safe at concentrations less than 5% in leave-on formulations.

Melanogenesis inhibitory and fibroblast proliferation accelerating effects of noroleanane- and oleanane-type triterpene oligoglycosides from the flower buds of Camellia japonica

A 28-noroleanane-type triterpene oligoglycoside, camellioside E (4), an oleanane-type triterpene oligoglycoside, camellioside F (5), and the known compounds camelliosides A (1) and D (3) were isolated from a 50% EtOH extract of Camellia japonica flower buds from Korea. The principal constituents (1 and 5) significantly inhibited melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells. Camellioside B (2), a major constituent of C. japonica grown in Japan, showed potent inhibition of melanogenesis [95.0 ± 1.0% (p < 0.01) at 20 μM]. The inhibitory effects of 1, 2, and 5 were stronger than that of the reference compound, arbutin. We believe the melanogenesis inhibitory effects of 2 and 5 are partly related to the proliferation inhibitory effects in B16 melanoma 4A5 cells. Conversely, camelliosides tended to enhance proliferation in normal human neonatal skin fibroblasts. Interestingly, camellioside B (2) significantly accelerated fibroblast proliferation. This biological selectivity could make camellioside B useful for treating skin disorders. Herein, we report the first scientific investigation of a triterpene that displays an inhibitory effect on melanogenesis, but that also has an enhancing effect on fibroblast proliferation.

Combined In Vitro Tests as an Alternative to In Vivo Eye Irritation Tests

Accurate methods that test the eye irritation potential of chemicals, which do not involve the use of animals, are needed to meet new regulatory standards. We evaluated the applicability and predictive capacity of five in vitro tests for eye irritation: the Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) assay; the Chorioallantoic Membrane-Trypan Blue Staining (CAM-TBS) assay; the Fluorescein Leakage Test (FLT); the 3T3-Neutral Red Uptake (3T3-NRU) cytotoxicity assay; and the red blood cell (RBC) haemolysis assay. A panel of 16 chemicals (some at multiple concentrations) was assessed by using the five tests, and the results were compared with historical in vivo Draize test data. The results showed rank correlation and class concordance between the five alternative methods and the Draize test for the 16 chemicals. These in vitro assays had good predictive capacity, reproducibility and reliability when compared to the Draize test. The best relationship was between the HET-CAM, CAM-TBS and FLT results, and the modified maximum average score(s) (MMAS). A prediction model (PM) was developed, based on the maximum possible correlation between the MMAS and the HET-CAM, CAM-TBS and FLT results. The PM had a good predictive capacity when compared to the results of animal tests, indicating its potential value for the in vitro screening of chemicals for eye irritation effects.

Hen Egg Chorioallantoic Membrane Bioassay: An In Vitro Alternative to Draize Eye Irritation Test for Pesticide Screening

As an alternative to the standard Draize eye irritation test, the potential irritancy of compounds was evaluated by observing adverse changes that occur in chorioallantoic membrane CAM) of the hen egg (HECAM) after exposure to a test chemical placed directly on the CAM. The occurrence of hemorrhage, coagulation, and lysis in response to a test compound is the basis for employing this technique to evaluate its potential for in vivo damage to mucous membrane, in particular the eye. Irritancy is scored according to the severity and speed at which damage occurs. In the present study, five different classes of pesticides were screened for irritation potential. There was good correlation between the HECAM assay and the in vivo Draize eye irritation test. The proposed HECAM assay, which reduces the requirement for laboratory animals, could be a painless alternative to the Draize test.

Evaluation of the Hen's Egg Test–Chorioallantonic Membrane (CAM) Method in Prediction of the Eye Irritation Potential Formulated Personal Wash Products

A large database has demonstrated a robust relationship between the chorioallantonic membrane (CAM) and the Draize rabbit eye tests. The precision, sensitivity, and direct correlation of the CAM with human eye evaluations were critically appraised in this work. A total of 24 studies, including 12 CAM assays and 12 human clinical studies were conducted. Both the CAM assay and the human tests demonstrated good interassay precision and a robust correlation between the CAM scores and the inflammatory responses of human eye bulbar conjunctiva, palpebral conjunctiva and scleral vessels. This provided sound evidence that the CAM assay could be a predictive screen for eye irritation assessment for personal wash products and a key element of the tiered scientific approach in supporting labeling claims such as "tear free".

W/O microemulsions for ocular delivery: Evaluation of ocular irritation and precorneal retention

Water-in-oil microemulsions (w/o ME) capable of undergoing a phase-transition to lamellar liquid crystals (LC) or bicontinuous ME upon aqueous dilution were formulated using Crodamol EO, Crill 1 and Crillet 4, an alkanol or alkanediol as cosurfactant and water. The hypothesis that phase-transition of ME to LC may be induced by tears and serve to prolong precorneal retention was tested. The ocular irritation potential of components and formulations was assessed using a modified hen's egg chorioallantoic membrane test (HET-CAM) and the preocular retention of selected formulations was investigated in rabbit eye using gamma scintigraphy. Results showed that Crill 1, Crillet 4 and Crodamol EO were non-irritant. However, all other cosurfactants investigated were irritant and their irritation was dependent on their carbon chain length. A w/o ME formulated without cosurfactant showed a protective effect when a strong irritant (0.1 M NaOH) was used as the aqueous phase. Precorneal clearance studies revealed that the retention of colloidal and coarse dispersed systems was significantly greater than an aqueous solution with no significant difference between ME systems (containing 5% and 10% water) as well as o/w emulsion containing 85% water. Conversely, a LC system formulated without cosurfactant displayed a significantly greater retention compared to other formulations.