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Titolo:
INTERACTION OF ALPHA-TOCOPHEROL ACETATE WITH PHOSPHATIDYLCHOLINE AND THEIR FORMATION OF SMALL DISPERSED PARTICLES
Autore:
ASAI Y; WATANABE S;
Indirizzi:
EISAI & CO LTD,FORMULAT RES LAB,KAWASHIMA CHO GIFU 5016195 JAPAN EISAI & CO LTD,TSUKUBA RES LABS TSUKUBA IBARAKI 3002635 JAPAN
Titolo Testata:
Chemical and Pharmaceutical Bulletin
fascicolo: 11, volume: 46, anno: 1998,
pagine: 1785 - 1789
SICI:
0009-2363(1998)46:11<1785:IOAAWP>2.0.ZU;2-H
Fonte:
ISI
Lingua:
ENG
Soggetto:
VITAMIN-E; VESICLES; BILAYERS; CHOLESTEROL; MEMBRANES; DIACYLGLYCEROL; LIPOPROTEINS; SPECTROSCOPY; MONOLAYERS; MIXTURES;
Keywords:
ALPHA-TOCOPHEROL ACETATE; DIPALMITOYLPHOSPHATYDYLCHOLINE; PARTICLE SIZE; TRAPPED VOLUME; MONOLAYER-BILAYER EQUILIBRIUM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
33
Recensione:
Indirizzi per estratti:
Citazione:
Y. Asai e S. Watanabe, "INTERACTION OF ALPHA-TOCOPHEROL ACETATE WITH PHOSPHATIDYLCHOLINE AND THEIR FORMATION OF SMALL DISPERSED PARTICLES", Chemical and Pharmaceutical Bulletin, 46(11), 1998, pp. 1785-1789

Abstract

Stable aqueous dispersions of alpha-tocopherol acetate (alpha-TA) were obtained by cosonication with dipalmitoylphosphatidylcholine (DPPC) in the alpha-TA mole fraction range of 0.1-0.8, In order to clarify the dispersal mechanism, the dispersed particles were characterized and the interaction between alpha-TA and DPPC was investigated using several physicochemical techniques. Dynamic light scattering measurements showed that the diameter of the dispersed particles was 50-75 nm, The trapped aqueous volume inside the particles was determined fluorometrically using the aqueous space marker calcein, The trapped volume in thealpha-TA/DPPC particles decreased remarkably with the addition of alpha-TA into small unilamellar vesicles of DPPC, The decline in the fraction of vesicular particles was also confirmed by fluorescence quenching of N-dansylhexadecylamine in the DPPC membrane by the addition of the quencher CuSO4. These results indicate that the excess alpha-TA separated from the DPPC bilayers is stabilized as emulsion particles by the DPPC surface monolayer, The monolayer-bilayer equilibrium of alpha-TA/DPPC mixtures was estimated by measurement of spreading and collapse pressures. The results showed that the coexistence of emulsion particles (surface monolayer of DPPC+core of alpha-TA) with vesicular particles (bilayer) was critically important for the formation of the stably dispersed particles of the lipid mixture.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 26/05/20 alle ore 06:07:31