Bioequivalence and Bioavailability Forum

Dear drgopal!

❝ If the drug is for psoariasis what are the restrictions for the subject in the study (protection from light) […]

Are you talking about Methoxsalen?

To quote Martindale (2002):
Adverse Effects:
Effects on the eyes.
Free methoxsalen has been detected in the lens of the eye for at least 12 hours after oral administration1 although it may become integrated into the structure of the lens and cataracts may occur in patients who fail to wear suitable eye protection for 12 to 24 hours after therapy. However, provided that eye protection is used there appears to be no significant dose-dependent increase in the risk of cataract formation […]. Psoralens may also increase the sensitivity of the retina to visible light.
Precautions:
Methoxsalen should not be given to patients with diseases associated with light sensitivity such as porphyria, although it is used with care to decrease some patients' sensitivity to sunlight.
Patients should not sunbathe for 24 hours before and 48 hours after PUVA treatment. They should avoid exposure to sun, even through glass or cloud cover for at least 8 hours after methoxsalen ingestion and patients should wear wrap-around UVA absorbing glasses for 24 hours after ingestion.
Interactions:
Food.
Some foods, for example, celery, parsnip, and parsley, contain psoralens and consumption of large quantities may increase the risk of phototoxicity with methoxsalen.

❝ […] and how will we take care of packing and transportation of the biological samples?

I don’t think that you have to follow special precautions, because samples in a box will be protected form light anyhow…