Addition of propylene glycol in CDBA-liposomes still achieved
photo-induced release of DOX as shown in Fig. 6. The result veri-
fied our assumption that the encapsulated active substance in
CDBA-liposomes could be released by UV irradiation according to
the fact that propylene glycol does not affect the photo-isomeriza tion of CDBA. When 20% propylene glycol mixed CDBA-liposomes
was irradiated by UV light for 1 h and then stored at 37 C for
2 h, approximately 10% DOX was released from CDBA-liposomes
after three cycles. However, only 4% DOX was released from the
CDBA-liposomes without propylene glycol after three cycles.
Therefore, propylene glycol seems to promote the release of the active inclusion to some extent