Determination of 8-methoxypsoralen levels in plasma and skin suction blister fluid by a new sensitive fluorodensitometric method

✍ Scribed by H. Ch. Korting; M. Schäfer-Korting; E. Roser-Maass; E. Mutschler

• Publisher: Springer-Verlag
• Year: 1981
• Tongue: English
• Weight: 617 KB
• Volume: 272
• Category: Article
• ISSN: 0340-3696
• DOI: 10.1007/bf00510388

✦ Synopsis

An improved fluorodensitometric assay for the determination of 8methoxypsoralen (8-MOP) in plasma is described. Because of its low limit of detection (below 1 rig/spot) this method is suitable to determine the drug in skin suction blister fluid, too. The standard deviation of the procedure is 6.4 % or less.

Plasma and skin blister fluid levels of 8-MOP are determined 2 h following oral administration of 40-60 mg 8-MOP. They range from 0-239 ng/ml and 0-163 ng/ml, respectively. A rather close correlation (r = 0.91) between these two parameters could be observed.

Thus, in cases with relatively high plasma levels sufficient skin levels can be predicted. If further investigations would prove, however, that a distinct concentration threshold required for therapeutic success exists -and recent experiments with fibroblast cultures imply that -skin blister fluid level determinations would seem highly desirable when plasma levels let us expect skin levels in the critical range.

In general determination of 8-MOP skin blister fluid levels can be looked upon as a model for the evaluation of drug skin levels after systemic application in man.