Might doctors performing the study have been given the wrong injection instructions?

EDITOR—I was surprised to read the letter from Robert Dow, chief executive of Scotia, stating that Foscan (temoporfin), a light activated anticancer drug, was originally reconstituted in water and is therefore water soluble.1

Foscan is highly insoluble in water and was never reconstituted in water but in a solution of ethanol, polyethylene glycol, and water. If any formulation of Foscan is injected into a saline filled needle it will precipitate. If an intravenous injection port has been flushed with saline before Foscan injection the vein is also likely to contain some saline and, on being injected, Foscan will precipitate along the vein walls, giving an …