CHROMATOGRAPHIC ANALYSIS OF PHOTODYNAMICALLY SIGNIFICANT PORPHYRIN DIMERS AND TRIMERS

Two porphyrin dimers, dihematoporphyrin dimer (DHD) and divinyl dimer (DVD), and two porphyrin trimers, dihematoporphyrin trimer (DHT) and d ivinyl trimer (DVT), have been analyzed utilizing isocratic ion-pair r eversed-phase high-performance liquid chromatography. Results indicate that the vinyl porphyrins can be distinguished by three peaks appeari ng near 15, 38, and 42 min. The hematoporphyrin complexes are identifi ed by the appearance of a peak located at 35 min. The DVT and DVD comp lexes present unique chromatographic markers at 28 and 15 min, respect ively. Based on the location of these chromatographic markers, it was found that the Photofrin(R) drug must contain the DVD and the DHT comp lexes, but does not contain the DVT complex. The purity of the DVT com plex is compromised by the presence of DHD and DHT impurities.