[Percutaneous absorption of hematoporphyrin derivative--fluorescence- and electron microscopic studies].

Using surviving human skin, percutaneous absorption following topical application of hematoporphyrin derivative was investigated. Hematoporphyrin derivative gave strong red fluorescence, which was dependent from it's actual concentration, from the used kind of vehicle, from preparation time, and from time between preparation and application of hematoporphyrin derivative solution. Ultrastructural investigation verified cytoplasmatic membranes and mitochondria as the principal targets also after topical application followed by irradiation with visible light.