Colloidal Structures in Media Simulating Intestinal Fed State Conditions with and Without Lipolysis Products
Författare
Summary, in English
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.
Avdelning/ar
- Department of Food Technology, Engineering and Nutrition
Publiceringsår
2009
Språk
Engelska
Sidor
361-374
Publikation/Tidskrift/Serie
Pharmaceutical Research
Volym
26
Issue
2
Dokumenttyp
Artikel i tidskrift
Förlag
Springer
Ämne
- Pharmaceutical Sciences
Nyckelord
- multilamellar vesicles
- micelles
- lipolytic products
- in vitro digestion lipolysis model
- microscopy
- cryogenic transmission electron
- zeta-potential
- biorelevant media
- unilamellar
- systems
- self-nanoemulsifying drug delivery
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1573-904X