Author/Editor		Gregorc, K; Kristl, J; Gabrijelčič, V; Šentjurc, M; Šmid-Korbar, J
Title		Physical stability of liposomes studied by EPR method
Translated title		Proučevanje fizikalne stabilnosti liposomov z EPR metodo
Type		članek
Source		Farm Vestn
Vol. and No.		Letnik 46, št. 2
Publication year		1995
Volume		str. 119-26
Language		eng
Abstract		Multilamellar and small unilamellar vesicles (MLV, SUV) with entrapped hydrophilic paramagnetic probe N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)-N,N-dimethyl-N-hydroxyethylammoniumdiodide (ASL) were prepared in water and dispersed in hydrogels of different hydrophilic polymers (xanthan gum, carboxymethylcellulose sodium). The physical stability of liposomes has been investigated by electron paramagnetic resonance (EPR) method measuring the amount of ASL released after its encapsulation into liposomes. On-going stability study shows that egg yolk lecithin and alpha-tocopherol acetate liposomes are more stable than soya lecithin liposomes, regardless of the dispersion medium composition. The results also show that some hydrophilic polymers and preservatives present in dispersion medium, influence the physical stability of liposomes.
Descriptors		LIPOSOMES DRUG STABILITY ELECTRON SPIN RESONANCE SPECTROSCOPY PHOSPHATIDYLCHOLINES VITAMIN E