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Colloidal Structures in Media Simulating Intestinal Fed State Conditions with and Without Lipolysis Products

Fatouros, Dimitrios G.; Walrand, Isabelle; Bergenståhl, Björn LU and Mullertz, Anette (2009) In Pharmaceutical Research 26(2). p.361-374
Abstract
Purpose. To study the ultrastructure of biorelevant media and digestion products of self-nanoemulsifying drug delivery system (SNEDDS) at high level BS/PL conditions. Methods. Cryogenic transmission electron microscopy (Cryo-TEM) was employed to visualize the colloid structures in the biorelevant media and lipolytic products generated during hydrolysis of a SNEDDS formulation. Their electrical properties were investigated by measuring their zeta-potential values. Results. In the biorelevant media, vesicles (either unilamellar or multilamellar) and bilayer fragments are visualized. Occasionally, vesicles with an internal deformed structure are recognized, suggesting surface tension or uneven lateral stress. Visualization studies of the... (More)
Purpose. To study the ultrastructure of biorelevant media and digestion products of self-nanoemulsifying drug delivery system (SNEDDS) at high level BS/PL conditions. Methods. Cryogenic transmission electron microscopy (Cryo-TEM) was employed to visualize the colloid structures in the biorelevant media and lipolytic products generated during hydrolysis of a SNEDDS formulation. Their electrical properties were investigated by measuring their zeta-potential values. Results. In the biorelevant media, vesicles (either unilamellar or multilamellar) and bilayer fragments are visualized. Occasionally, vesicles with an internal deformed structure are recognized, suggesting surface tension or uneven lateral stress. Visualization studies of the intermediate colloidal phases produced during digestion of a SNEDDS using the in vitro lipolysis model revealed the formation of similar structures as previously reported. The zeta-potential of the media was negatively charged and decreased from -23 to -35 mV with increasing surfactant/lipid load. Lower zeta-potential values (-16 mV) obtained for the structures formed during the lipid hydrolysis of the SNEDDS were probably due to the presence of calcium, which shields the surface, thereby reducing the charge. Conclusions. The diversity of these vesicles in terms of size, lamellarity, and internal organization advocate their important role during lipid digestion in the gastrointestinal milieu. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
multilamellar vesicles, micelles, lipolytic products, in vitro digestion lipolysis model, microscopy, cryogenic transmission electron, zeta-potential, biorelevant media, unilamellar, systems, self-nanoemulsifying drug delivery
in
Pharmaceutical Research
volume
26
issue
2
pages
361 - 374
publisher
Springer
external identifiers
  • wos:000262570400011
  • scopus:58549106999
ISSN
1573-904X
DOI
10.1007/s11095-008-9750-9
language
English
LU publication?
yes
id
be2aa4be-3787-437e-95d2-6e18dd08b63f (old id 1312445)
date added to LUP
2009-03-13 14:10:43
date last changed
2017-05-21 03:36:46
@article{be2aa4be-3787-437e-95d2-6e18dd08b63f,
  abstract     = {Purpose. To study the ultrastructure of biorelevant media and digestion products of self-nanoemulsifying drug delivery system (SNEDDS) at high level BS/PL conditions. Methods. Cryogenic transmission electron microscopy (Cryo-TEM) was employed to visualize the colloid structures in the biorelevant media and lipolytic products generated during hydrolysis of a SNEDDS formulation. Their electrical properties were investigated by measuring their zeta-potential values. Results. In the biorelevant media, vesicles (either unilamellar or multilamellar) and bilayer fragments are visualized. Occasionally, vesicles with an internal deformed structure are recognized, suggesting surface tension or uneven lateral stress. Visualization studies of the intermediate colloidal phases produced during digestion of a SNEDDS using the in vitro lipolysis model revealed the formation of similar structures as previously reported. The zeta-potential of the media was negatively charged and decreased from -23 to -35 mV with increasing surfactant/lipid load. Lower zeta-potential values (-16 mV) obtained for the structures formed during the lipid hydrolysis of the SNEDDS were probably due to the presence of calcium, which shields the surface, thereby reducing the charge. Conclusions. The diversity of these vesicles in terms of size, lamellarity, and internal organization advocate their important role during lipid digestion in the gastrointestinal milieu.},
  author       = {Fatouros, Dimitrios G. and Walrand, Isabelle and Bergenståhl, Björn and Mullertz, Anette},
  issn         = {1573-904X},
  keyword      = {multilamellar vesicles,micelles,lipolytic products,in vitro digestion lipolysis model,microscopy,cryogenic transmission electron,zeta-potential,biorelevant media,unilamellar,systems,self-nanoemulsifying drug delivery},
  language     = {eng},
  number       = {2},
  pages        = {361--374},
  publisher    = {Springer},
  series       = {Pharmaceutical Research},
  title        = {Colloidal Structures in Media Simulating Intestinal Fed State Conditions with and Without Lipolysis Products},
  url          = {http://dx.doi.org/10.1007/s11095-008-9750-9},
  volume       = {26},
  year         = {2009},
}