S. Kristensen et al., PHOTOREACTIVITY OF BIOLOGICALLY-ACTIVE COMPOUNDS .7. INTERACTION OF ANTIMALARIAL-DRUGS WITH MELANIN IN-VITRO AS PART OF PHOTOTOXICITY SCREENING, Journal of photochemistry and photobiology.B, Biology, 26(1), 1994, pp. 87-95
The drugs commonly used in the treatment of malaria are photochemicall
y unstable. Several of these compounds accumulate in melanin-rich tiss
ues and cause toxic reactions which may be light induced. As part of t
he screening of the photochemical properties and phototoxic capabiliti
es of antimalarials, the in vitro interaction of eight antimalarials w
ith melanin was studied. The dissociation constant for the drug-melani
n complex and the relative number of binding sites on melanin were est
imated for six of the drugs using a curve-fitting program. The reactio
n rate for the formation of the melanin-drug complex was determined, a
nd the complexes were further characterized by zeta potential measurem
ents.