Repetitive irritation test

Frosch, PJ. and Kurte, A., Efficacy of skin barrier creams (IV). The repetitive irritation test (RIT) with a set of 4 standard irritants, Contact Dermatitis, 31, 161, 1994. 

Frosch PJ, Schulze-Dirks A, Hoffmann M, Axthelm I (1993) Efficacy of skin barrier creams. (II). Ineffectiveness of a popular skin protector against various irritants in the 49. repetitive irritation test in the guinea pig. Contact Dermatitis... 

Schlater-Wigger W, Eisner P (1996) Efficacy of 4 commercially available protective creams in the repetitive irritation test (RIT), Contact Dermatitis 34 278-283... 

Several randomized studies with humans have been realized a human patch test for 72 h and a repetitive epicutaneous test for 6 weeks, as well as tests on the influence of nanocellulose on the moistness of the skin after short-term treatment (20 min, measuring of moistness up to 12 h after treatment). The results demonstrate that the applied nanocellulose will not cause any unwanted skin reactions due to irritating, sensitizing, or early allergic effects and the moistness of the treated... 

Many bioassays have been proposed for the purpose of identifying sensitive skin. A 24-h patch test with sodium lauryl sulphate (SLS) and repetitive patch tests, such as the 21-day cumulative-irritation assay, the chamber scarification test, and the soap-chamber test, have been used (Lee and Maibach 1994). 

Cumulative irritation The scope of this study is to determine long-term irritation potentials under exaggerated conditions or to assess and compare the mildness of formulations. It consists of a controlled patch test involving 15-30 subjects using 14-21 repetitive 24 h applications. The FDA recommends a 21 day patch test in a 30-subject panel. For more irritating cosmetics, a 14 day application would satisfy the objective of the study. 

Humans Toluene Several BCs All tested BCs markedly reduced the irritating effect of repetitive toluene contact Grunewald et al. [39]... 

Due to the lack of previous data on contact of the test material with human skin, the open application test is performed gradually, starting with one volunteer and increasing the panel size step by step. The duration of application is also gradual, with a standard application time of 30 min which can later be extended. When a single open application has not induced irritation, repeated open applications can start to mimic a situation in which a subject would come repetitively in contact with the neat product. 

---