US EPA

1071172 

Journal Article 

Freeze-drying of liposomes using tertiary butyl alcohol/water cosolvent systems 

Cui, J; Li, C; Deng, Y; Wang, Y; Wang, W 

2006 

Yes 

International Journal of Pharmaceutics
ISSN: 0378-5173
EISSN: 1873-3476 

312 

1-2 

131-136 

English 

16459032 

10.1016/j.ijpharm.2006.01.004 

WOS:000236823000017 

The objective of this study was to obtain dehydrated liposomes using a novel procedure that involves freeze-drying (FD) of liposomes with TBA/water cosolvent systems. The effects of TBA on the integrity/stability of vesicles of HSPC (or SPC):Cholesterol (4:1) were investigated. TBA used as a cosolvent was detrimental to SPC liposomes, leading to increased particle size and leakage of trapped calcein. However, this was not the case for HSPC liposomes. The vesicle size and the retention of trapped calcein after lyophilization from cosolvents were similar to those after FD from water alone. Moreover, the addition of TBA can significantly enhance the sublimation of ice resulting in short FD cycles. The resulting lyophilized cake can form a loose powder upon agitation, which flowed well enough to be easily poured from the vial. Thus FD of HSPC liposomes using TBA/water cosolvent systems can provide sterile powder for specialized applications. In addition, in conjunction with a modified injection method, this FD technology might be used to produce dehydrated HSPC liposomes on a large scale. 

liposomes; preparation; freeze-drying; cosolvents; tertiary butyl alcohol