Quil A-lipid powder formulations releasing ISCOMs and related colloidal stuctures upon hydration

Demana, PH, Davies, NM, Hook, S and Rades, T (2005) Quil A-lipid powder formulations releasing ISCOMs and related colloidal stuctures upon hydration. Journal of Controlled Release, 103 1: 45-59. doi:10.1016/j.jconrel.2004.11.027

Author Demana, PH
Davies, NM
Hook, S
Rades, T
Title Quil A-lipid powder formulations releasing ISCOMs and related colloidal stuctures upon hydration
Journal name Journal of Controlled Release   Check publisher's open access policy
ISSN 0168-3659
Publication date 2005-01-01
Sub-type Article (original research)
DOI 10.1016/j.jconrel.2004.11.027
Open Access Status Not yet assessed
Volume 103
Issue 1
Start page 45
End page 59
Total pages 15
Editor W.E. Hennink
C.G. Pitt
Place of publication Netherlands
Publisher Elsevier Bv
Language eng
Subject C1
320501 Pharmaceutical Sciences and Pharmacy
730101 Infectious diseases
Abstract The aim of the present study was to prepare solid Quil A-cholesterol-phospholid formulations (as powder mixtures or compressed to pellets) by physical mixing or by freeze-drying of aqueous dispersions of these components in ratios that allow spontaneous formation of ISCOMs and other colloidal stuctures upon hydration. The effect of addition of excess cholesterol to the lipid mixtures on the release of a model antigen (PE-FITC-OVA) from the pellets was also investigated. Physical properties were evaluated by X-ray powder diffractometry (XPRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and polarized light microscopy (PLM). Characterization of aqueous colloidal dispersions was performed by negative staining transmission electron microscopy (TEM). Physically mixed powders (with or without PE-FITC-OVA) and pellets prepared from the same powders did not spontaneously form ISCOM matrices and related colloidal structures such as worm-like micelles, ring-like micelles, lipidic/layered structures and lamellae (hexagonal array of ring-like micelles) upon hydration as expected from the pseudo-temary diagram for aqueous mixtures of Quil A, cholesterol and phospholipid. In contrast, spontaneous formation of the expected colloids was demonstrated for the freeze-dried lipid mixtures. Pellets prepared by compression of freeze-dried powders released PE-FITC-OVA slower than those prepared from physically mixed powders. TEM investigations revealed that the antigen was released in the form of colloidal particles (ISCOMs) from pellets prepared by compression of freeze-dried powders. The addition of excess cholesterol slowed down the release of antigen. The findings obtained in this study are important for the formulation of solid Quil A-containing lipid articles as controlled particulate adjuvant containing antigen delivery systems. (c) 2004 Elsevier B.V. All rights reserved.
Keyword Chemistry, Multidisciplinary
Pharmacology & Pharmacy
Physical Mixing
Immune-stimulating Complexes
Film Hydration
Aqueous Mixtures
Q-Index Code C1
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2006 Higher Education Research Data Collection
School of Pharmacy Publications
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Citation counts: TR Web of Science Citation Count  Cited 21 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 23 times in Scopus Article | Citations
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Created: Wed, 15 Aug 2007, 16:18:57 EST