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In vivo PHOTODEGRADATION OF CHLORPROMAZINE
Author(s) -
Schoonderwoerd S. A.,
Henegouwen G. M. J. Beijersbergen Van,
Belkum S. Van
Publication year - 1989
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1989.tb04323.x
Subject(s) - photodegradation , promazine , chlorpromazine , chemistry , in vivo , photochemistry , irradiation , metabolite , biophysics , pharmacology , biochemistry , catalysis , medicine , biology , photocatalysis , physics , microbiology and biotechnology , nuclear physics
— The in vivo photodegradation of chlorpromazine (CPZ) in the skin was investigated after systemic administration of 3 H‐CPZ to shaven Wistar rats and exposure to UV‐A. Promazine (PZ) and 2‐hydroxy‐promazine (2‐OH‐PZ) appeared to be formed in irradiated rats, but not in the skin of rats kept in the dark. This indicates that upon irradiation with UV‐A the PZ‐radical is formed which can be held responsible for the photobinding to eye and skin constituents as observed earlier [Schoonder‐woerd and Beijersbergen von Henegouwen (1987) Photochem. Photobiol. 46, 501–505]. Chlorpromaz‐ine‐sulfoxide (CPZSO) is a major metabolite of CPZ. Less CPZSO was found in the skin of irradiated rats compared to those kept in the dark. As this appeared not to be caused by photobinding or photodegradation of CPZSO it can be concluded that CPZSO is not a photoproduct of CPZ under these experimental conditions. This study shows that the in vivo photodegradation of CPZ proceeds via the promazinyl radical rather than via the radical cation.