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Published on: September 7, 2013
Isobutylamido thiazolyl resorcinol for prevention of UVB-induced hyperpigmentation
Vasanop Vachiramon1, Chaninan Kositkuljorn1, Kanchana Leerunyakul1
1Division of Dermatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Background:
Isobutylamido thiazolyl resorcinol (ITR, Thiamidol® ) has been proposed as a potent tyrosinase inhibitor. A formulation containing ITR has recently shown promising efficacy for the treatment of some hyperpigmentary conditions.
Objectives:
This study aimed to evaluate the efficacy and safety of ITR in the prevention of ultraviolet (UV)-induced hyperpigmentation in human skin.
Materials And Methods:
We performed a randomized, single-blinded, pilot study in 30 healthy participants. One arm was randomly assigned to receive an ITR-containing product for three weeks. Three hyperpigmented spots were induced by UVB irradiation on both arms after 3 weeks of ITR application. Outcome evaluations included measuring mean lightness index (*L) obtained by colorimeter, hyperpigmentation scores by visual analog scale (VAS), and adverse effects.
Results:
Both experimental sides showed no significant difference in terms of skin lightening after ITR application. However, the ITR-treated sides showed a statistically significant lower mean lightness index compared to control after an induction with UVB. In addition, the ITR-treated sides had an earlier improvement and resumed the normal skin color after 3 weeks post-UVB induction. A clinical evaluation by a blinded nontreating physician and subjects was more favorable on the ITR-treated side than the control side (P < .05). No significant side effect was noted.
Conclusions:
ITR is an effective agent in the prevention of pigmentary change from UVB irradiation and may serve as a promising agent for preventing other hyperpigmentary conditions.
