PT  - JOURNAL ARTICLE
AU  - Yotsuyanagi, Toshihisa
AU  - Nonomura, Muneo
AU  - Ikeda, Ken
TI  - Ultrasonic Size Reduction of Liposomes and Volume Estimation of Internal Aqueous Phase
DP  - 1981 Nov 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 271--276
VI  - 35
IP  - 6
4099  - http://journal.pda.org/content/35/6/271.short
4100  - http://journal.pda.org/content/35/6/271.full
SO  - PDA J Pharm Sci Technol1981 Nov 01; 35
AB  - The relationship between ultrasonic size reduction of liposomes characterized by gel filtration and the entrapped aqueous volume estimated from the dilution method was studied. The incorporation of cholesterol exhibited greater physical stability of the vesicles against ultrasonic vibration force. There was little difference of the entrapped aqueous volume between pure lecithin and lecithin-cholesterol (2:1) liposomes when the volume was expressed in terms of liters per mole of total lipid. The results imply that the cholesterol molecules incorporated participate in the formation of the concentric bilayer structure as much as the lecithin molecule does on the molecular volume basis. Entrapping efficiencies of liposomes consisting of pure lecithin and of lecithin-cholesterol (2:1) mixture were described for adriamycin. When cholesterol was incorporated, the loading capacity was roughly 2.5 times greater than that of the pure lecithin liposomes.