Because other deliery systems, especially those containing surfactants, commonly used with HPPH and many other drugs, may add to the toxicity in the body, they hae been considered imperfect solutions.

• 因为其它传输系统，特别是含有表面活性剂的传输系统（常用于HPPH及其它药物）都有可能对人体产生毒性，这些系统被认为是不完美的。