Topical rose bengal: pre-clinical evaluation of pharmacokinetics and safety.
OBJECTIVE
Rose bengal (RB) is a potent photosensitizer that has largely been overlooked as a potential photodynamic therapy (PDT) agent. In this study, the feasibility of topical delivery of RB to the epidermis has been evaluated.


METHODS
Topical formulations of RB were assessed on murine and rabbit skin for pharmacokinetic properties, cutaneous toxicity, and photosensitization.


RESULTS
Hydrophilic formulations (<or=1% RB) exhibited rapid, selective, uniform delivery to the epidermis, with no significant acute cutaneous toxicity in normal skin. Illumination (532 nm) elicited no acute phototoxicity for light intensities <or=100 mW/cm(2) at a light dose of 100 J/cm(2); use of higher intensities resulted in superficial thermal damage. Repeat treatment of rabbit skin (weekly for four weeks) elicited minor phototoxicity only at the highest concentration (1% RB).


CONCLUSIONS
These results indicate that RB is safe for PDT treatment of skin disorders, exhibiting negligible effects in normal skin.
Wachter
Eric
E
Provectus Pharmaceuticals, Inc., Knoxville, Tennessee 37931, USA. wachter@provectuscorp.com
Dees
Craig
C
Harkins
Jay
J
Scott
Timothy
T
Petersen
Mark
M
Rush
Rusty E
RE
Cada
Amy
A
D000279:Administration, Cutaneous; D000818:Animals; D017484:Dermatitis, Phototoxic / Q000209:etiology; D004307:Dose-Response Relationship, Radiation; D004353:Drug Evaluation, Preclinical; D005240:Feasibility Studies; D005260:Female; D005456:Fluorescent Dyes / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008853:Microscopy; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D011817:Rabbits; D012395:Rose Bengal / Q000493:pharmacokinetics / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects* / Q000528:radiation effects*
D005456:Fluorescent Dyes; D017319:Photosensitizing Agents; D012395:Rose Bengal