Publicação
Enteric coating of weakly basic drug tablets : a study on the process and release profiles
| Resumo: | There are primarily three factors governing absorption process once a drug is in solution: the physicochemical characteristics of the molecule, the properties and components of the GI fluids, and the nature of the absorbing membrane (14). It is known that the small intestine is the major site of drug absorption, and thus the time a drug is present in this part of the gastrointestinal tract is extremely significant. If sustained or enteric controlled-release drug delivery systems are being designed, it is important to consider factors that will affect their behavior, like pH dissolution (13). Many enteric polymers can be used to coat tablets, preventing from acidic degradation. In this work it was used Eudragit L-100 as the enteric polymer combined in different ratios with Klucel EXF or Methocel E5, to coat weakly basic drug tablets. Coating process efficiency was between 76.02% and 88.48%, for equipment and process condition reasons. Drug release profiles results corresponded to what was expected, as formulation with higher ratio of Eudragit L-100 and Klucel EXF showed the retarded release at acidic pH. |
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| Autores principais: | Lamelas, Sara Filipa Marchã Xerez |
| Assunto: | Mestrado Integrado - 2014 |
| Ano: | 2014 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | There are primarily three factors governing absorption process once a drug is in solution: the physicochemical characteristics of the molecule, the properties and components of the GI fluids, and the nature of the absorbing membrane (14). It is known that the small intestine is the major site of drug absorption, and thus the time a drug is present in this part of the gastrointestinal tract is extremely significant. If sustained or enteric controlled-release drug delivery systems are being designed, it is important to consider factors that will affect their behavior, like pH dissolution (13). Many enteric polymers can be used to coat tablets, preventing from acidic degradation. In this work it was used Eudragit L-100 as the enteric polymer combined in different ratios with Klucel EXF or Methocel E5, to coat weakly basic drug tablets. Coating process efficiency was between 76.02% and 88.48%, for equipment and process condition reasons. Drug release profiles results corresponded to what was expected, as formulation with higher ratio of Eudragit L-100 and Klucel EXF showed the retarded release at acidic pH. |
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