Oleogels as controlled delivery systems for probiotics
(2024)- Abstract
- A new encapsulation strategy for probiotics is highly needed to tackle the challenge of significant viability loss of bacteria during storage and passage through the gastrointestinal system. A new controlled delivery system for probiotics based on EC oleogels is proposed in this thesis.
A relatively non-complicated in vitro lipolysis model was established to evaluate the relative conversion from triglycerides to free fatty acids and the retarding effect on lipolysis. Using this in vitro model, EC oleogels show a good retarding effect.
To apply EC oleogels as the controlled delivery system for Limosilactobacillus reuteri, a cold-mixing method was developed to tackle the high-temperature requirement. Using the cold-mixing method,... (More) - A new encapsulation strategy for probiotics is highly needed to tackle the challenge of significant viability loss of bacteria during storage and passage through the gastrointestinal system. A new controlled delivery system for probiotics based on EC oleogels is proposed in this thesis.
A relatively non-complicated in vitro lipolysis model was established to evaluate the relative conversion from triglycerides to free fatty acids and the retarding effect on lipolysis. Using this in vitro model, EC oleogels show a good retarding effect.
To apply EC oleogels as the controlled delivery system for Limosilactobacillus reuteri, a cold-mixing method was developed to tackle the high-temperature requirement. Using the cold-mixing method, probiotics were successfully encapsulated in oleogels. Meanwhile, oleogels are harmless to the bacteria,
have protection against a lethal environment at the early part of the intestine (high bile concentrations and various enzymes), and can deliver live bacteria to the target location (ileum and colon). The main limitation is the limited release of encapsulated bacteria within 120 min.
By adding different excipients (lipid excipients and hydrophilic powder excipients) during the cold-mixing step, different release kinetics and release mechanisms can be obtained. Accelerating release (the ideal release kinetic) over time can be obtained by adding disintegrants or the combination of lipid excipients and disintegrants. A full release can also be achieved over a certain time.
The 90-day storage stability study (30°C/75% relative humidity and 40°C/75% relative humidity) shows that EC oleogels remain relatively stable after a short relaxation period (less than a week at room temperature). Furthermore, EC oleogels can keep the high viability of the encapsulated bacteria (less than 1 log10 decrease in viability after 90 days at 40°C), protect the encapsulated bacteria in the in vitro solution, and deliver a high number of live bacteria to the ileum and colon.
To conclude, EC oleogels have good protection during storage and passage through the upper part of the gastrointestinal system. Meanwhile, EC oleogel formulations can deliver a high number of live bacteria to the target location. Hence, EC oleogels serve as a promising controlled-release delivery system for probiotics. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/ae5cb24e-2dea-4ed0-a98d-1b005652a2ff
- author
- Zhang, Lingping LU
- supervisor
- opponent
-
- Prof. Mörck Nielsen, Hanne, University of Copenhagen, Denmark.
- organization
- publishing date
- 2024-05-20
- type
- Thesis
- publication status
- published
- subject
- pages
- 71 pages
- publisher
- Department of Process and Life Science Engineering, Lund University.
- defense location
- Lecture Hall KC:A, Kemicentrum, Naturvetarvägen 14, Faculty of Engineering LTH, Lund University, Lund. The dissertation will be live streamed, but part of the premises is to be excluded from the live stream.
- defense date
- 2024-06-14 09:15:00
- ISBN
- 978-91-8096-037-3
- 978-91-8096-036-6
- language
- English
- LU publication?
- yes
- id
- ae5cb24e-2dea-4ed0-a98d-1b005652a2ff
- date added to LUP
- 2024-05-20 15:08:00
- date last changed
- 2024-05-30 13:59:22
@phdthesis{ae5cb24e-2dea-4ed0-a98d-1b005652a2ff,
abstract = {{A new encapsulation strategy for probiotics is highly needed to tackle the challenge of significant viability loss of bacteria during storage and passage through the gastrointestinal system. A new controlled delivery system for probiotics based on EC oleogels is proposed in this thesis. <br/>A relatively non-complicated in vitro lipolysis model was established to evaluate the relative conversion from triglycerides to free fatty acids and the retarding effect on lipolysis. Using this in vitro model, EC oleogels show a good retarding effect. <br/>To apply EC oleogels as the controlled delivery system for Limosilactobacillus reuteri, a cold-mixing method was developed to tackle the high-temperature requirement. Using the cold-mixing method, probiotics were successfully encapsulated in oleogels. Meanwhile, oleogels are harmless to the bacteria, <br/>have protection against a lethal environment at the early part of the intestine (high bile concentrations and various enzymes), and can deliver live bacteria to the target location (ileum and colon). The main limitation is the limited release of encapsulated bacteria within 120 min. <br/>By adding different excipients (lipid excipients and hydrophilic powder excipients) during the cold-mixing step, different release kinetics and release mechanisms can be obtained. Accelerating release (the ideal release kinetic) over time can be obtained by adding disintegrants or the combination of lipid excipients and disintegrants. A full release can also be achieved over a certain time. <br/>The 90-day storage stability study (30°C/75% relative humidity and 40°C/75% relative humidity) shows that EC oleogels remain relatively stable after a short relaxation period (less than a week at room temperature). Furthermore, EC oleogels can keep the high viability of the encapsulated bacteria (less than 1 log10 decrease in viability after 90 days at 40°C), protect the encapsulated bacteria in the in vitro solution, and deliver a high number of live bacteria to the ileum and colon. <br/>To conclude, EC oleogels have good protection during storage and passage through the upper part of the gastrointestinal system. Meanwhile, EC oleogel formulations can deliver a high number of live bacteria to the target location. Hence, EC oleogels serve as a promising controlled-release delivery system for probiotics.}},
author = {{Zhang, Lingping}},
isbn = {{978-91-8096-037-3}},
language = {{eng}},
month = {{05}},
publisher = {{Department of Process and Life Science Engineering, Lund University.}},
school = {{Lund University}},
title = {{Oleogels as controlled delivery systems for probiotics}},
url = {{https://lup.lub.lu.se/search/files/183803704/Thesis_Lingping_Zhang_LUCRIS.pdf}},
year = {{2024}},
}