These results concur with the literature, demonstrating a more efficient retention of compounds when the liposomes are in their solid gel phase (below Tc) than in the liquid phase (above Tc) . Chen et al. measured calcein release from liposomal formulations of different phosphatidylcholine composition at a temperature below the Tc of all formulations. The authors demonstrated that calcein release correlated to the Tc with as little as 7% released after 11 h for HSPC containing liposomes (Tc = 53.7 °C) compared to 43% for pure DPPC liposomes (Tc = 42.4 °C) . While DSPC-10 (Tc = 49.7 °C) liposomes present a slower peptide release (<5% at RT) over the first 4 h compared to the other two formulations (Figure ), this was not statistically significant (Two-way ANOVA, p> 0.05) and otherwise no marked difference between formulations of different Tc.