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The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia

BACKGROUND: We prepared an oral W/O microemulsion for the removal of colonic ammonia (ME-RCA). The effect of this microemulsion was influenced by the digestion process in the gastrointestinal tract. In this paper, we aim to show that stability was improved by using a microemulsion-based gel for the...

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Autores principales: Wang, Ai-Hong, Duan, Zhi-Jun, Tian, Ge, Lu, Dan, Zhang, Wen-Jun, He, Gao-Hong, Fang, Gui-Hua
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3112116/
https://www.ncbi.nlm.nih.gov/pubmed/21569230
http://dx.doi.org/10.1186/1471-230X-11-50
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author Wang, Ai-Hong
Duan, Zhi-Jun
Tian, Ge
Lu, Dan
Zhang, Wen-Jun
He, Gao-Hong
Fang, Gui-Hua
author_facet Wang, Ai-Hong
Duan, Zhi-Jun
Tian, Ge
Lu, Dan
Zhang, Wen-Jun
He, Gao-Hong
Fang, Gui-Hua
author_sort Wang, Ai-Hong
collection PubMed
description BACKGROUND: We prepared an oral W/O microemulsion for the removal of colonic ammonia (ME-RCA). The effect of this microemulsion was influenced by the digestion process in the gastrointestinal tract. In this paper, we aim to show that stability was improved by using a microemulsion-based gel for the removal of colonic ammonia (MBG-RCA). METHODS: MBG-RCA was prepared by adding sodium alginate to the ME-RCA. MBG-RCA and ME-RCA were passed through a simulated gastrointestinal environment, and the amount of colonic ammonia present was then determined by titration with a standard solution of hydrochloric acid. The pH of the gastrointestinal fluid was measured using a pH test paper and the size and form of the microemulsions were examined under the microscope. 18 healthy rats were randomly divided into three groups, fasted for 24 hours and allowed to drink normally. Three-way pipes were placed at the gastroduodenal junction in Group I, and at the terminal ileum in Group II. After the intragastric administration of ME-RCA, the stomach contents in Group I, the effluent from the terminal ileum in Group II and discharge from the anus in Group III were collected. The pH values of the gastrointestinal juice were measured by the pH test paper and those of the colon were determined by a universal indicator. These animal experiments were also used to test the effect of MBG-RCA. RESULTS: MBG-RCA showed a better removal rate of artificial colonic ammonia than ME-RCA (P < 0.05). The decrease in pH value of the artificial small intestinal fluid due to ME-RCA did not occur when MBG-RCA was used. In the simulated gastrointestinal process, MBG-RCA maintained greater stability and released the emulsion (ME-RCA) in the colonic fluid. In the gastrointestinal tract of normal SD rats, ME-RCA decreased in size and lost its stable form after entering the small intestine, while MBG-RCA remained stable and intact emulsion-drops were observed from the anus. Neither substance had any effect on the pH of the stomach or colon of normal rats (partly because normal rats were fasted for 24 hours and allowed to drink normally, which resulted in a low level of ammonia production in the colon). Unlike ME-RCA, MBG-RCA did not reduce the pH of the small intestine. CONCLUSIONS: MBG-RCA was more stable in the gastrointestinal tract and more effective at removing colonic ammonia when a higher concentration of ammonia was present. This made it possible to achieve the targeted removal of colonic ammonia and is a promising method to prevent hepatic encephalopathy (HE) in future studies.
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spelling pubmed-31121162011-06-11 The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia Wang, Ai-Hong Duan, Zhi-Jun Tian, Ge Lu, Dan Zhang, Wen-Jun He, Gao-Hong Fang, Gui-Hua BMC Gastroenterol Research Article BACKGROUND: We prepared an oral W/O microemulsion for the removal of colonic ammonia (ME-RCA). The effect of this microemulsion was influenced by the digestion process in the gastrointestinal tract. In this paper, we aim to show that stability was improved by using a microemulsion-based gel for the removal of colonic ammonia (MBG-RCA). METHODS: MBG-RCA was prepared by adding sodium alginate to the ME-RCA. MBG-RCA and ME-RCA were passed through a simulated gastrointestinal environment, and the amount of colonic ammonia present was then determined by titration with a standard solution of hydrochloric acid. The pH of the gastrointestinal fluid was measured using a pH test paper and the size and form of the microemulsions were examined under the microscope. 18 healthy rats were randomly divided into three groups, fasted for 24 hours and allowed to drink normally. Three-way pipes were placed at the gastroduodenal junction in Group I, and at the terminal ileum in Group II. After the intragastric administration of ME-RCA, the stomach contents in Group I, the effluent from the terminal ileum in Group II and discharge from the anus in Group III were collected. The pH values of the gastrointestinal juice were measured by the pH test paper and those of the colon were determined by a universal indicator. These animal experiments were also used to test the effect of MBG-RCA. RESULTS: MBG-RCA showed a better removal rate of artificial colonic ammonia than ME-RCA (P < 0.05). The decrease in pH value of the artificial small intestinal fluid due to ME-RCA did not occur when MBG-RCA was used. In the simulated gastrointestinal process, MBG-RCA maintained greater stability and released the emulsion (ME-RCA) in the colonic fluid. In the gastrointestinal tract of normal SD rats, ME-RCA decreased in size and lost its stable form after entering the small intestine, while MBG-RCA remained stable and intact emulsion-drops were observed from the anus. Neither substance had any effect on the pH of the stomach or colon of normal rats (partly because normal rats were fasted for 24 hours and allowed to drink normally, which resulted in a low level of ammonia production in the colon). Unlike ME-RCA, MBG-RCA did not reduce the pH of the small intestine. CONCLUSIONS: MBG-RCA was more stable in the gastrointestinal tract and more effective at removing colonic ammonia when a higher concentration of ammonia was present. This made it possible to achieve the targeted removal of colonic ammonia and is a promising method to prevent hepatic encephalopathy (HE) in future studies. BioMed Central 2011-05-10 /pmc/articles/PMC3112116/ /pubmed/21569230 http://dx.doi.org/10.1186/1471-230X-11-50 Text en Copyright ©2011 Wang et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Wang, Ai-Hong
Duan, Zhi-Jun
Tian, Ge
Lu, Dan
Zhang, Wen-Jun
He, Gao-Hong
Fang, Gui-Hua
The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
title The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
title_full The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
title_fullStr The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
title_full_unstemmed The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
title_short The addition of a pH-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
title_sort addition of a ph-sensitive gel improves microemulsion stability for the targeted removal of colonic ammonia
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3112116/
https://www.ncbi.nlm.nih.gov/pubmed/21569230
http://dx.doi.org/10.1186/1471-230X-11-50
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