Effects of light on metalloporphyrin-treated newborn mice.

UNLABELLED: Zinc protoporphyrin (ZnPP) is a promising metalloporphyrin with sufficient potency, but has poor solubility and is not absorbed well orally. Intragastric administration of ZnPP microparticles (30 µmol/kg) to 3-day-old mice resulted in a twofold increase in potency and no signs of phototoxicity. CONCLUSION: The use of polymeric particulate delivery systems can improve the stability and enhance intestinal absorption of ZnPP, while retaining HO inhibitory potency without photosensitising effects, and thus is potentially useful in treating neonatal hyperbilirubinemia.