DRUG PHOTOTOXICITY TESTING
Abnormal photosensitivity of the human skin due to interaction between sun or an artificial light source and a therapeutic agent, has become of increasing importance in recent years, not only to patients but also to the Pharmaceutical Industry, research workers and Regulatory Authorities.
The problem for a new drug under development is to define the phototoxic potential and, if present, its essential characteristics.
Phototoxicity research has advanced in the past five years and the Photobiology Unit, which works closely with the company, Spectratox Ltd., under the direction of Professor James Ferguson, combined with Chiltern (Early Phase) Ltd (CEP) in Scotland, is a world leader in both conducting and consulting on photobiology clinical trials for regulatory purposes.
CEP collaborates with a recognized expert in the field of photobiology, who over the past 15 years has performed phototoxicity studies for the world's largest pharmaceutical and biotechnology companies.
CLINICAL PHOTOTOXICITY TRIAL WORK
Where a new drug is considered to be a potential photosensitiser, the technique developed in the Dundee Photobiology Unit is designed to answer a number of questions:
• Is your drug photoactive in humans or not?
• If so, what is the degree of photosensitivity?
• What is the wavelength dependency and the drug dosage relationship?
• Are there likely to be long term pigmentation or phototoxic ocular effects?
• What is the nature of the response and duration of susceptibility after stopping the drug?
The study technique in healthy volunteers is conducted blind with placebo and positive phototoxic comparator drug control. It is designed to provide the essential information on predicting whether there is a problem with a particular agent. The study also provides information on the duration of photosensitivity following drug cessation, possible long-term sequelae as well as advising on prevention.
When a drug is shown to be phototoxic, advice on how to protect against, and even prevent this problem is available at Chiltern (Early Phase) Ltd.
