It is known that membrane fluidity of liposomes affects the release profiles as well as a retention time of drug encapsulated into liposomes. Therefore, we investigated the effects of γ-CyD on membrane fluidity of AF-liposomes using a Microcal MC2 scanning calorimeter. In the present study, we utilized N-liposomes to eliminate the effects of the heat degeneration of AF in a DSC thermograph. Figure 9 shows the effects of γ-CyD and HP-γ-CyD on DSC thermograms of N-liposomes (5 mM of total lipids). The peak derived from gel-to-fluid state transition in N-liposomes was observed at 55 • C, while new peak was appeared at 42 • C in the presence of 50 mM of γ-CyD (Figure 9(a) ). On the other hand, no significant change in DSC thermographs was observed in the presence of HP-γ-CyD (Figure 9(b) ). These results suggest that γ-CyD may affect the membrane fluidity of Nliposomes.