Sistema multiparticulado magnético: desenvolvimento e avaliação In Vivo através da biossusceptometria AC
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Data
2010-02-25
Autores
Oliveira, Giselle Faria [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Neste estudo foi desenvolvido um sistema multiparticulado magnético (SMM) à base de quitosana (QS), pectina (PC) e acetoftalato de celulose (CAP), pelo método da coacervação complexa. O sistema contém um glicocorticóide, a triancinolona (TC), e, como material magnético, a ferrita (F). Em estudos anteriores, este SMM mostrou-se promissor para conduzir a liberação modificada de fármacos para a região colônica. Segundo análises in vitro, ele associou a liberação pH-dependente à liberação enzimática, típica do ambiente colônico. Entretanto, devido à complexidade do trato gastrintestinal (TGI), torna-se essencial que formas farmacêuticas desenvolvidas para liberação alvo-específica sejam avaliadas in vivo, para que se possa estabelecer uma correlação in vitro/in vivo adequada. Baseado nesses fatos, o objetivo deste trabalho foi o monitoramento do trânsito gastrintestinal (TG) do sistema proposto até sua chegada ao cólon, através de uma técnica não invasiva, livre de radiação, a Biosusceptometria de Corrente Alternada (BAC), que pudesse avaliar o trânsito gastrintestinal (TG) do SMM em voluntários saudáveis em jejum e no estado alimentado. Foram também realizadas análises do perfil de liberação in vivo da TC. Os resultados obtidos mostraram que o sistema desenvolvido foi capaz de produzir campo magnético de intensidade suficiente para ser detectado e que a BAC foi capaz de monitorar o trânsito gastrintestinal do SMM até sua chegada ao cólon. O estado pós-prandial influenciou significativamente o esvaziamento gástrico, sendo o tempo médio de 107,5 min ± 43,37 min no estado de jejum e de 260min ± 67,64 min no estado alimentado. Além do esvaziamento gástrico mais demorado no estado alimentado, o trânsito pelo intestino delgado e a chegada ao cólon também foram influenciados pelo estado pós-prandial. Não foi possível estabelecer correlação...
In this study a magnetic multiparticulate system (MMS) based on chitosan (CS), pectin (PC) and cellulose acetophtalate (CAP) was developed by means of a complex coacervation method. The system contains a glucocorticoid, triamcinolone (TC), and ferrite (F) as magnetic material. In earlier studies, this MMS showed to be a promising system for modified drug release to target the colonic region. As in vitro analyses proved, it was able to associate pHdependent and enzymatic controlled, typical from the colonic environment, drug releases. However, due to the complexity of the gastrointestinal tract (GIT), it is essential that pharmaceutical dosage forms developed to perform target specific drug release may be evaluated also in vivo, in order to establish an adequate in vitro/in vivo correlation. Based on these issues, the aim of this work was the monitoring of the gastrointestinal transit (GT) of the proposed system until it reaches the colon, by means of a non-invasive, radiation free technique, namely the Alternate Current Biosusceptometry (ACB), which could evaluate the MMS transit in healthy volunteers both in fasting and fed states. Analyses of the in vivo TC release profile were also carried out. The results showed that the developed system was able to generate magnetic field strong enough to be detected and that ACB was efficient to monitoring the MMS transit until its arrival in the colon. The postprandial state influenced significantly the gastric emptying, being 260.0 min ± 67.64 min the mean time for the fed state and 107.5 min ± 43.37 min for the fasting state. Additionally to a longer gastric emptying time, the transit within the small intestine and the arrival in the colon were also influenced by the postprandial state. It was not possible to establish a valid in vivo/in vitro correlation between the drug released profiles... (Complete abstract click electronic access below)
In this study a magnetic multiparticulate system (MMS) based on chitosan (CS), pectin (PC) and cellulose acetophtalate (CAP) was developed by means of a complex coacervation method. The system contains a glucocorticoid, triamcinolone (TC), and ferrite (F) as magnetic material. In earlier studies, this MMS showed to be a promising system for modified drug release to target the colonic region. As in vitro analyses proved, it was able to associate pHdependent and enzymatic controlled, typical from the colonic environment, drug releases. However, due to the complexity of the gastrointestinal tract (GIT), it is essential that pharmaceutical dosage forms developed to perform target specific drug release may be evaluated also in vivo, in order to establish an adequate in vitro/in vivo correlation. Based on these issues, the aim of this work was the monitoring of the gastrointestinal transit (GT) of the proposed system until it reaches the colon, by means of a non-invasive, radiation free technique, namely the Alternate Current Biosusceptometry (ACB), which could evaluate the MMS transit in healthy volunteers both in fasting and fed states. Analyses of the in vivo TC release profile were also carried out. The results showed that the developed system was able to generate magnetic field strong enough to be detected and that ACB was efficient to monitoring the MMS transit until its arrival in the colon. The postprandial state influenced significantly the gastric emptying, being 260.0 min ± 67.64 min the mean time for the fed state and 107.5 min ± 43.37 min for the fasting state. Additionally to a longer gastric emptying time, the transit within the small intestine and the arrival in the colon were also influenced by the postprandial state. It was not possible to establish a valid in vivo/in vitro correlation between the drug released profiles... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Quitosana, Tecnologia farmacêutica, Biossusceptometria AC, Acetoftalato de celulose, Gastrointestinal transit, Chitosan, Pectin, Cellulose acetate phtalate
Como citar
OLIVEIRA, Giselle Faria. Sistema multiparticulado magnético: desenvolvimento e avaliação In Vivo através da biossusceptometria AC. 2010. 139 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, 2010.