A Study on the Minimal Phototoxic Dose (MPD)

Kim, Yoon Seong; Park, Jang Kyu

Abstract

In order to measure the MPD with 8-methoxypsoralen, we selected 49 Korean healthy male vlunteers without phototoxic or photosensitive dermatoses. They were divided to 3 groups (Immediate; group 1, 1 hour; group 2, 2 hours', group 3) according to the waiting time, intervals of application of photosensitizer a,nd UVA:irradiation. The reaults were summarized as follows: 1. MPDs of group 1 had no clinical significance. 2, MPDs of group 2 were more than those of group '3 independently of application methods of photosensitizer. 3. In the cases of topical application of 8-MOP, MPDs of group 3 according to reading interval (24 hours, 48 hours and 72 hours after UVA irradiation) were 3.4+/-2.9 J/cm2, 1.9+/-l.5 J/cm' and l. 7+1, 2/cm, respectively. 4 In the cases of oral administration of 8-MOP, MPDs of group 3 according to reading; interval as topical application of 8-MOP were 7.1+/-2.3 J/cm, 4.4+/-1.1 J/ cm2 and 4.2+/-l.2 J/cm2, respectively. 5 MPL)s accarding to the skin types as follows; (waiting time; 2 hours, read- ing interval; 48 hours) a. In the case of topical application of 8-MOP, MPDs of the skin type ]II, 1V and V were 0.9+/-0.5 J/cm2, 1.8+/-1.1 J/cm2 and 3.0+/-l.3 J/cm2 respectively. b. In the case of oral administration of 8-MOP, MPDs of skin type g, W and were 3.5+/-1.1 J/cm2, 4.7+/-1.3 J/cm2 and 6.9+/-l.8 J/cm2, respectively.