2.6. Photo-isomerization and stability of CDBA-liposomes mixed with
propylene glycol and glycerol
Irradiation of CDBA-liposomes was carried out as described
above. The stability of CDBA-liposomes when mixed with 5%, 20%
and 50% propylene glycol at various storage conditions was
estimated by monitoring the release of a fluorescent molecule
DOX from CDBA-liposome solution. The liposomal solution was
incubated in a water bath at 15 C for 24 h, then transferred to
50 C for 24 h, this process was repeated for three times. The
encapsulation efficacy of DOX was measured by a fluorescence
spectrophotometer (kex = 505 nm, kem = 550 nm, Hitachi F-2500,
Japan). The amount of DOX encapsulated in the liposomes was
calculated by the equation: Encapsulation Efficiency
(%) = 100 (Imax Io)/(Imax), where Io is the fluorescence intensity
of the liposomal suspension containing DOX at the initial time,
and Imax is the maximum fluorescence intensity after the addition