Biological activities of preparations of HPD

Abstract

The dosimetry parameters of photodynamic therapy (PDT) are contingent upon several factors including laser wavelength, power, energy density, dosage and retention interval (RI) of photosensitizer, and most importantly the biological activity of the photosensitizer. Although the photosensitizer hematoporphyrin derivative (HPD) is available conmercially, many laboratories still make and use their own preparations of HPD. In order for investigators to compare dosimetry and results of PDT, it is necessary that the efficacy of each preparation of HPD used is known. Our laboratory employs a simple in vitro assay to determine the biological activity of HPD batches.The dosimetry parameters of photodynamic therapy (PDT) are contingent upon several factors including laser wavelength, power, energy density, dosage and retention interval (RI) of photosensitizer, and most importantly the biological activity of the photosensitizer. Although the photosensitizer hematoporphyrin derivative (HPD) is available conmercially, many laboratories still make and use their own preparations of HPD. In order for investigators to compare dosimetry and results of PDT, it is necessary that the efficacy of each preparation of HPD used is known. Our laboratory employs a simple in vitro assay to determine the biological activity of HPD batches.