Serum level profiles of 8-methoxypsoralen after oral administration

Comparison between Plasma Levels of 8-Methoxypsoralen and Skin Photosensitivity: The Interest of Pharmacokinetic Studies during Photochemotherapy of Psoriasis

“…It can thus be affirmed that for a given patient the phototoxicity is greatest when the 8-MOP plasma level is maximal; on the other hand, there is no correlation be tween the absolute values of plasma 8-MOP in ng/ml and MPD in J/cm2, as has been demonstrated by Thuneand Volden [10] and Steiner et al [7], In other words, individu ally, the 8-MOP level reflects skin photosen sitivity, but from one subject to the next, the value of the MPD depends essentially on the constitutive sensitivity of the patient to UV, which is evaluated by the Fitzpatrick's skin type.…”

Problems with Commercial Formulations of 8-Methoxypsoralen

“…Interindividual variations in plasma concentrations were also reported for solid 8-MOP formulations available in different countries [1,2,4,9,11,12]. Intraindividual variations were also reported [4].…”

“…A large interindividual variation was found for the plasma levels of 8-MOP measured in patients at the time of irradiation, 2 h after intake of the product [I I], but also for the plasma level profiles measured in function of time [2,9], Due to the poor water solubility of 8-MOP [5], absorption from the tablet formulations is rather low, and different reports show low and even undetectable plasma levels after oral ingestion of tablet formulations of 8-MOP [1,4,12]. There fore, other drug formulations were developed to obtain a more rapid and complete drug absorption [3,8,10].…”

Relations entre les taux plasmatiques du 8-méthoxypsoralène et l’effet phototoxique

“…Quelques auteurs [1,2,5,6] ont déjà étudié ce problè me, mais arrivent à des résultats contradic toires.…”