Publicação
Granules for treatment of intestinal bacterial infections
| Resumo: | Diarrheal diseases are estimated to cause millions of deaths annually, primarily among children under five years old living in low- and middle-income countries. The intestinal pathogenic Escherichia coli (InPEC) is one of the major responsible agents for these diseases worldwide. This pathogen not only causes diarrheal disease but is also responsible for other medical problems like haemorrhagic colitis and haemolytic uremic syndrome. For a full recovery and a complete pathogen eradication, a specific antibiotic regimen (usually three doses per day for five days) should be taken. This is particularly difficult when administering to small children, as they cannot swallow tablets and often refuse multiple doses. Hence, this project focused on developing two granulated intestinal release systems (slow and fast) allowing for a single daily administration. The drug release from the granules should only start when it reaches the intestine to allow the full dose to reach the infection site and promote the continuous release of the antibiotic (levofloxacin) at bactericidal concentrations for extended period of time. The granule matrixes incorporated Generally Regarded as Safe (GRAS) excipients with functions of diluents, binders and disintegrants as well as an enteric polymeric coating. The granules were prepared using a wet granulation methodology and evaluated in terms of antimicrobial activity, release, stability and cytotoxicity. The optimization of the granular formulation led to the production of a fast-release system - batch loaded-K – and slow-release systems – batches loaded-L. Both systems were used for drug release evaluation in order to assess the release profile obtained under colonic simulated environment. The fast-release formulation released all drug content after 15 min of dissolution testing. As for the slow-release formulation, the dissolution profile indicated to be dependent on the concentration of the matrix component HPMC K4M: the higher the excipient concentration, the slower the release of the drug from the matrix. Loaded-K batch was evaluated for stability, antimicrobial activity and cytotoxicity. This formulation proved to exhibit an identical dissolution profiling after 5 shelf-months. On a biological level, this formulation exhibited a visible inhibitory effect against E. coli bacteria. Furthermore, this batch was tested for cytotoxicity profiling on Caco-2 cells and red blood cells. In conclusion, loaded-K formulation demonstrated a non-toxic profile towards intestinal epithelial cells and erythrocytes, indicating an overall safety of this formulation while maintaining the antibacterial activity of loaded levofloxacin. |
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| Autores principais: | Boas, Ana Margarida Martins Vilas |
| Assunto: | Colonic delivery Granules Intestinal pathogenic E. coli Levofloxacin Wet granulation E. coli intestinal patogénica Entrega colónica Granulação húmida Grânulos Levofloxacina |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Diarrheal diseases are estimated to cause millions of deaths annually, primarily among children under five years old living in low- and middle-income countries. The intestinal pathogenic Escherichia coli (InPEC) is one of the major responsible agents for these diseases worldwide. This pathogen not only causes diarrheal disease but is also responsible for other medical problems like haemorrhagic colitis and haemolytic uremic syndrome. For a full recovery and a complete pathogen eradication, a specific antibiotic regimen (usually three doses per day for five days) should be taken. This is particularly difficult when administering to small children, as they cannot swallow tablets and often refuse multiple doses. Hence, this project focused on developing two granulated intestinal release systems (slow and fast) allowing for a single daily administration. The drug release from the granules should only start when it reaches the intestine to allow the full dose to reach the infection site and promote the continuous release of the antibiotic (levofloxacin) at bactericidal concentrations for extended period of time. The granule matrixes incorporated Generally Regarded as Safe (GRAS) excipients with functions of diluents, binders and disintegrants as well as an enteric polymeric coating. The granules were prepared using a wet granulation methodology and evaluated in terms of antimicrobial activity, release, stability and cytotoxicity. The optimization of the granular formulation led to the production of a fast-release system - batch loaded-K – and slow-release systems – batches loaded-L. Both systems were used for drug release evaluation in order to assess the release profile obtained under colonic simulated environment. The fast-release formulation released all drug content after 15 min of dissolution testing. As for the slow-release formulation, the dissolution profile indicated to be dependent on the concentration of the matrix component HPMC K4M: the higher the excipient concentration, the slower the release of the drug from the matrix. Loaded-K batch was evaluated for stability, antimicrobial activity and cytotoxicity. This formulation proved to exhibit an identical dissolution profiling after 5 shelf-months. On a biological level, this formulation exhibited a visible inhibitory effect against E. coli bacteria. Furthermore, this batch was tested for cytotoxicity profiling on Caco-2 cells and red blood cells. In conclusion, loaded-K formulation demonstrated a non-toxic profile towards intestinal epithelial cells and erythrocytes, indicating an overall safety of this formulation while maintaining the antibacterial activity of loaded levofloxacin. |
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