Repeat Open Application Test

Cosmetics come into direct contact with the surface of the human body during use, and if there is a problem with the product, it can have serious consequences, including skin reactions. The patch test is a commonly used cosmetic safety test that examines the potential for a subject to cause adverse skin reactions in humans. Common types of skin patch tests are available, including occlusive patch tests, repeat open application test, and human repeated insult patch test. For blemish-removing cosmetics and powdered (e.g., powder, foundation) sunscreen cosmetics, the repeat open application test should be added when irritation results are difficult to determine in the human skin patch test.

Repeat Open Application Test

• Test Steps

• Take the flexed side of the forearm as the test site, with an area of 3 cm × 3 cm, the test site should be kept dry and avoid contact with other topical preparations.
• Apply the test substance evenly to the test site twice a day for 7 consecutive days while observing the skin reaction. If a skin reaction of 3 points or more occurs during the process, it should be decided whether to continue the test or not according to the specific situation.
• Skin reaction shall be observed according to the criteria for determining skin reaction in the repeat open application test, and the results shall be recorded.

• Repeat Open Application Test Evaluation Principles

There shall be no more than 5 cases of Grade 1 adverse skin reactions, no more than 2 cases of Grade 2 adverse skin reactions, or no more than 1 case of Grade 3 or above adverse skin reactions. If the above requirements are exceeded, it suggests that the test article may cause adverse reactions to human skin.

• Test Procedure

Upon arrival of the sample at the laboratory, the test substance will be given an individual laboratory test number and will be documented and verified by the laboratory logbook with the lot number, sample specification, sponsor, date of receipt and test request.

Volunteer Screening: In the opinion of the researcher, the test subjects must not have any systemic or dermatologic history that would impede the results of the test or increase the risk of adverse reactions, and if the skin color is suitable for erythema observation, any skin nature and any ethnicity can be involved in the test, and a final sample of 53 people is selected for the study.

The test is divided into a triggering phase and an excitation phase, and the test is repeated several times to determine whether or not the subject has developed erythema or other adverse irritation.

The Advantages of Repeat Open Application Test

• Innovative solutions with a wide range of services

CD Formulation can provide one-stop innovative solutions for cosmetic products, including but not limited to: physicochemical testing, microbiological testing, toxicological testing, safety assessment, cosmetic efficacy testing.

• Wide range of services and abundant cases

CD Formulation has established in-depth relationships with many industry benchmark companies to provide scientific validation services in a series of processes such as product development.

CD Formulation is committed to providing customers with the highest quality ROAT testing services. Our team of experts has years of experience in performing ROAT testing and is committed to providing accurate and reliable results. We utilize state-of-the-art equipment and technology to ensure that our tests are efficient and effective. In addition, we offer customized ROAT testing protocols to meet the specific needs of our clients, providing them with a personalized and customized approach to their testing requirements.