For HRIPT, a total of 9 induction patches were applied at the rate of three patches per week for three weeks. The patch was retained in place for 48 hours during week days and 72 hrs over the weekend. Each induction patch was applied to the same site unless the degree of reaction to the test substance or the adhesive necessitates relocation. Two sites, adjacent to the original site, were available if patch relocation was deemed necessary. A rest period of 12-20 days between the final induction patch application and challenge patch application was provided. Challenge patches were applied 12-20 days after the last induction patch application. Patches were worn for 48 hours (± 1 hour), then removed at the site and discarded.
For PT, the test products along with a blank chamber as negative control were applied on the back of the subjects in contralateral paired symmetry under occlusion for 24 hours. After completion of 24 hours of occlusion, both patch systems were taken off. Subjects were acclimatized for 30 minutes post removal of the patch and dermatological assessment of the sites (including controls) was performed. Post assessment, one of the two sites and an untreated blank control site (randomized and investigator blinded) was irradiated with 0.5 MED (specific for each subject). Follow up assessments were performed at 10 minutes post irradiation and subsequently at 24 and 48 hours post irradiation.
For CIT, the patches were prepared in a vertical row and applications were made every day for 14 days. All applications for individual test substances were made to the same site (the site used for the initial patch application) unless reactions become so strong (grade of 2.0 or greater) as to make continued application inadvisable. Patches were worn for approximately 23 hours (± 1 hour). Subjects were instructed to keep their patches dry. Subjects were instructed to return to the test facility for patch removal and disposal by test facility personnel. Skin sites were gently wiped with water and patted dry to remove excess test substance immediately following patch removal. Skin sites were graded approximately 20-40 minutes following patch removal. Subjects were not allowed to replace any patches that fall off. Subjects were provided with instructions and a schedule of the study dates on the first day of the study. Telephone numbers were provided to report adverse events or answer questions on a 24-hour basis.