Perfluoroalklylated phospholipids as surfactants and co-surfactants forinjectable fluorocarbon emulsions

Highly fluorinated phospholipids were investigated as sole surfactant, and as co-surfactant with egg yolk phospholipids (EYP), in the formulation of 50% and 100% w/v perfluorodecalin emulsions. The surfactant's capability to stabilize such emulsions improves with the length of the perfluoroalklylated tail and with the increase of its relative weight in the hydrophobic chain. As sole surfactant, 2, which has the longest fluorinated tail has the highest efficacy. As co-surfactant with EYP, a strong stabilizing effect is found when the total hydrophobic chain length is adjusted to the EYP membrane's thickness, which is the case of 1. Dispersions of the F-phospholipids do not modify cell growth and viability and show no hemolytic activity on human red blood cells at concentrations in the 60-100g/L range. Acute toxicity tests in mice indicate - i.v. DL50 greater than 2.75 g/Kg body wt.