C. Cornelus et al., IMPACT OF THE STRUCTURE OF PHOSPHOLIPID DISPERSIONS ON THE STABILITY OF FLUOROCARBON PHOSPHOLIPID EMULSIONS FOR BIOMEDICAL USES, Colloids and surfaces. A, Physicochemical and engineering aspects, 70(3), 1993, pp. 233-238
The preparation of injectable fluorocarbon emulsions includes the disp
ersion of the phospholipids in the aqueous phase, then the admixing of
the fluorocarbon to produce a crude premix; emulsification is then ac
hieved using a high pressure mechanical procedure, followed by final h
eat-sterilization. In this work we report that, depending on the proce
dure used and energy applied, the dispersions of phospholipids consist
of poorly organized unclosed ''pre-liposomes'', multilamellar vesicle
s (MLV), or small unilamellar vesicles (SUV). This has a significant i
mpact on the stability of the final fluorocarbon emulsions (90% (w/v)
concentration), those prepared from ''pre-liposomes'' being more stabl
e than those prepared from MLV or SUV. The first emulsion is shown to
contain less fluorocarbon-free phospholipid vesicles than the other tw
o. These free vesicles have previously been reported to have a detrime
ntal effect on the stability of concentrated fluorocarbon emulsions.