Liposomes encapsulating polymeric chitosan based vesicles - a vesicle in vesicle system for drug delivery

Donald McPhail, L. Tetley, Christine Dufès, I.F. Uchegbu

Research output: Contribution to journalArticle

  • 34 Citations

Abstract

Drug delivery systems comprising vesicles prepared from one amphiphile encapsulating vesicles prepared from a second amphiphile have not been prepared previously due to a tendency of the bilayer components of the different vesicles to mix during preparation. Recently we have developed polymeric vesicles using the new polymer-palmitoyl glycol chitosan and cholesterol in a 2:1 weight ratio. These polymeric vesicles have now been encapsulated within egg phosphatidylcholine (egg PC), cholesterol (2:1 weight ratio) liposomes yielding a vesicle in vesicle system. The vesicle in vesicle system was visualised by freeze fracture electron microscopy. The mixing of the different bilayer components was studied by monitoring the excimer fluorescence of pyrene-labelled polymeric vesicles after their encapsulation within egg PC liposomes or hexadecyl diglycerol ether niosomes. A minimum degree of lipid mixing was observed with the polymeric vesicle-egg PC liposome system when compared to the polymeric vesicle-hexadecyl diglycerol ether niosome system. The polymeric vesicle-egg PC vesicle in vesicle system was shown to retard the release of encapsulated solutes. 28% of 5(6)-carboxyfluorescein (CF) encapsulated in the polymeric vesicle compartment of the vesicle in vesicle system was released after 4 h compared to the release of 62% of encapsulated CF from plain polymeric vesicles within the same time period.
LanguageEnglish
Pages73-86
Number of pages14
JournalInternational Journal of Pharmaceutics
Volume200
Issue number1
DOIs
StatePublished - 2000

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Chitosan
Drug Delivery Systems
Liposomes
Phosphatidylcholines
Ovum
Cholesterol
Weights and Measures
Electron Microscopy
Polymers
Fluorescence
Lipids
diglycerol hexadecyl ether
6-carboxyfluorescein

Keywords

  • liposomes
  • phosphatidylcholine
  • chitosan
  • glycol chitosan
  • polymeric vesicles
  • multi-component systems
  • niosomes

Cite this

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title = "Liposomes encapsulating polymeric chitosan based vesicles - a vesicle in vesicle system for drug delivery",
abstract = "Drug delivery systems comprising vesicles prepared from one amphiphile encapsulating vesicles prepared from a second amphiphile have not been prepared previously due to a tendency of the bilayer components of the different vesicles to mix during preparation. Recently we have developed polymeric vesicles using the new polymer-palmitoyl glycol chitosan and cholesterol in a 2:1 weight ratio. These polymeric vesicles have now been encapsulated within egg phosphatidylcholine (egg PC), cholesterol (2:1 weight ratio) liposomes yielding a vesicle in vesicle system. The vesicle in vesicle system was visualised by freeze fracture electron microscopy. The mixing of the different bilayer components was studied by monitoring the excimer fluorescence of pyrene-labelled polymeric vesicles after their encapsulation within egg PC liposomes or hexadecyl diglycerol ether niosomes. A minimum degree of lipid mixing was observed with the polymeric vesicle-egg PC liposome system when compared to the polymeric vesicle-hexadecyl diglycerol ether niosome system. The polymeric vesicle-egg PC vesicle in vesicle system was shown to retard the release of encapsulated solutes. 28{\%} of 5(6)-carboxyfluorescein (CF) encapsulated in the polymeric vesicle compartment of the vesicle in vesicle system was released after 4 h compared to the release of 62{\%} of encapsulated CF from plain polymeric vesicles within the same time period.",
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Liposomes encapsulating polymeric chitosan based vesicles - a vesicle in vesicle system for drug delivery. / McPhail, Donald; Tetley, L.; Dufès, Christine; Uchegbu, I.F.

In: International Journal of Pharmaceutics, Vol. 200, No. 1, 2000, p. 73-86.

Research output: Contribution to journalArticle

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T1 - Liposomes encapsulating polymeric chitosan based vesicles - a vesicle in vesicle system for drug delivery

AU - McPhail,Donald

AU - Tetley,L.

AU - Dufès,Christine

AU - Uchegbu,I.F.

PY - 2000

Y1 - 2000

N2 - Drug delivery systems comprising vesicles prepared from one amphiphile encapsulating vesicles prepared from a second amphiphile have not been prepared previously due to a tendency of the bilayer components of the different vesicles to mix during preparation. Recently we have developed polymeric vesicles using the new polymer-palmitoyl glycol chitosan and cholesterol in a 2:1 weight ratio. These polymeric vesicles have now been encapsulated within egg phosphatidylcholine (egg PC), cholesterol (2:1 weight ratio) liposomes yielding a vesicle in vesicle system. The vesicle in vesicle system was visualised by freeze fracture electron microscopy. The mixing of the different bilayer components was studied by monitoring the excimer fluorescence of pyrene-labelled polymeric vesicles after their encapsulation within egg PC liposomes or hexadecyl diglycerol ether niosomes. A minimum degree of lipid mixing was observed with the polymeric vesicle-egg PC liposome system when compared to the polymeric vesicle-hexadecyl diglycerol ether niosome system. The polymeric vesicle-egg PC vesicle in vesicle system was shown to retard the release of encapsulated solutes. 28% of 5(6)-carboxyfluorescein (CF) encapsulated in the polymeric vesicle compartment of the vesicle in vesicle system was released after 4 h compared to the release of 62% of encapsulated CF from plain polymeric vesicles within the same time period.

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