A carregar...
Publicação
DESENVOLVIMENTO DE UM PENSO DÉRMICO DE CONTROLO ELETRÓNICO PARA A LIBERTAÇÃO DE FÁRMACO
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 4.36 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
Os sistemas de libertação controlada de fármacos são uma alternativa terapêutica a con-
siderar, principalmente quando se pretende minimizar os efeitos secundários inerentes a tera-
pêuticas prolongadas ou com concentrações elevadas de fármacos via oral ou injetável. Estes
sistemas têm a capacidade de libertar uma quantidade específica de fármaco num determi-
nado local. Até à data têm sido investigadas várias formas alternativas de administração con-
trolada de fármacos, nomeadamente, hidrogéis, nanopartículas e dispositivos baseados na im-
pregnação de membranas.
A libertação controlada de fármacos via estimulação elétrica a partir de fibras impregna-
das com fármaco foi estudada, usando membranas de acetato de celulose eletrofiadas e o
ibuprofeno encapsulado, um dos anti-inflamatórios não esteroides mais consumidos.
Desenvolveram-se cinco sistemas de membranas biocompatíveis que, para possibilitar a
aplicação de um estímulo elétrico, foram funcionalizados com dois polímeros condutores, po-
lipirrol e poli(3,4-etilenodioxitiofeno). A cinética de libertação do fármaco foi analisada e os
métodos de libertação passiva (difusão) e ativa (estímulo elétrico) foram realizados e compa-
rados.
Os resultados obtidos permitiram concluir que a libertação de fármaco é sensível a dois
potenciais elétricos para cada sistema. Quando aplicado o potencial de -0,3 V os sistemas ten-
dem a reter a libertação de fármaco e quando aplicado o potencial de +0,3 V, +0,5 V ou +0,8
V consoante o sistema, é libertado mais fármaco no meio, face aos resultados obtidos por
libertação passiva. Por fim, um pequeno penso adesivo para aplicação cutânea foi construído
com estes sistemas de membranas para libertação controlada por estímulos elétricos do ibu-
profeno incorporado, o qual verificou um padrão de libertação “
ON/OFF”.
Controlled drug delivery systems are a therapeutic alternative to be considered, mainly when the intention is to minimize the side effects inherent to prolonged therapies or with high concentrations of drugs via oral or injectable routes. These systems have the capacity to release a specific quantity of drug at a specific location. To date, several alternative forms of controlled drug delivery have been investigated, including hydrogels, nanoparticles, and membrane-im- pregnated devices. Controlled drug release via electrical stimulation from drug impregnated fibers has been studied using electrophilic cellulose acetate membranes and encapsulated ibuprofen, one of the most widely used non-steroidal anti-inflammatory drugs. Five biocompatible membrane systems were developed, which to enable the application of an electrical stimulus were functionalized with two conducting polymers, polipyrrole and poly(3,4-ethylenedioxythiophene). The kinetics of drug release was analyzed, and the methods of passive (diffusion) and active (electrical stimulation) release were performed and compared. The results obtained led to the conclusion that the drug release is sensitive to two elec- trical potentials for each system. When a potential of -0.3 V is applied, the systems tend to retain the release of the drug and when a potential of +0.3 V, +0.5 V or +0.8 V is applied depending on the system, more drug is released into the medium, compared with the results obtained by passive release. Finally, a small adhesive patch for cutaneous application was con- structed with these membrane systems for controlled release by electrical stimulation of the incorporated ibuprofen, which verified an "ON/OFF" release pattern.
Controlled drug delivery systems are a therapeutic alternative to be considered, mainly when the intention is to minimize the side effects inherent to prolonged therapies or with high concentrations of drugs via oral or injectable routes. These systems have the capacity to release a specific quantity of drug at a specific location. To date, several alternative forms of controlled drug delivery have been investigated, including hydrogels, nanoparticles, and membrane-im- pregnated devices. Controlled drug release via electrical stimulation from drug impregnated fibers has been studied using electrophilic cellulose acetate membranes and encapsulated ibuprofen, one of the most widely used non-steroidal anti-inflammatory drugs. Five biocompatible membrane systems were developed, which to enable the application of an electrical stimulus were functionalized with two conducting polymers, polipyrrole and poly(3,4-ethylenedioxythiophene). The kinetics of drug release was analyzed, and the methods of passive (diffusion) and active (electrical stimulation) release were performed and compared. The results obtained led to the conclusion that the drug release is sensitive to two elec- trical potentials for each system. When a potential of -0.3 V is applied, the systems tend to retain the release of the drug and when a potential of +0.3 V, +0.5 V or +0.8 V is applied depending on the system, more drug is released into the medium, compared with the results obtained by passive release. Finally, a small adhesive patch for cutaneous application was con- structed with these membrane systems for controlled release by electrical stimulation of the incorporated ibuprofen, which verified an "ON/OFF" release pattern.
Descrição
Palavras-chave
sistemas de libertação controlada de fármaco ibuprofeno acetato de celulose eletrofiação polímeros condutores polipirrol