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Sistemas farmacêuticos para administração vaginal: estado da arte
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| PPG_20137 | 1.54 MB | Adobe PDF |
Advisor(s)
Abstract(s)
No que concerne às vias de administração de fármacos, a via oral foi sempre uma das mais utilizadas. Contudo, vários investigadores têm explorado a utilização de vias de administração alternativas seguras e consideradas mais eficazes para administrar fármacos que apresentam limitada absorção oral ou sofram precocemente metabolização. Neste contexto, a administração medicamentosa por via vaginal tem sido bastante explorada nos últimos anos. A mucosa vaginal apresenta diversas vantagens, tais como a fácil acessibilidade, a elevada superfície específica, permite obter uma ação local ou sistémica, apresenta uma elevada vascularização e permite a permeação a certos fármacos, evitando o efeito de primeira passagem hepática. No entanto, as formulações para administração vaginal devem atender diversas especificações inerentes ao próprio local de aplicação, como seja o pH vaginal, a atividade enzimática, a microflora vaginal, as alterações cíclicas e a composição e características do fluido vaginal.
Atualmente, existe uma grande variedade de sistemas farmacêuticos para administração vaginal, desde os mais tradicionais, como as soluções, pomadas, cremes, geles e comprimidos vaginais, até aos mais recentes, tais como os anéis vaginais, filmes vaginais e nanossistemas. Entre os vários sistemas, as formulações mucoadesivas surgem como as mais promissoras para substituir as formas farmacêuticas convencionais, uma vez que permitem um aumento do tempo de permanência do fármaco no local de aplicação, com consequente aumento da sua eficácia terapêutica.
A presente dissertação consiste na revisão bibliográfica relativa ao estado da arte dos principais sistemas farmacêuticos não convencionais para administração vaginal, entre os quais se destacam as ciclodextrinas, as microesferas, as microemulsões, os dendrímeros, o filme vaginal, o anel vaginal, os lipossomas e as nanopartículas poliméricas. Para uma melhor compreensão do mecanismo de ação, fez-se inicialmente uma breve revisão da anatomia e da fisiologia da vagina.
Regarding the administration routes of drugs, the oral route has always been one of the most used. However, many researchers have been exploring the use of safe administration routes and considered more effective delivery systems to administrate drugs which have limited oral absorption or undergo early metabolization. In this context, the drug vaginal administration has been well explored in recent years. The vaginal mucosa presents several advantages such as easy accessibility, a high specific surface which allows local or systemic action, high vascularization and permeation to certain drugs, avoiding the hepatic first pass effect. However, the formulations for vaginal administration should take in account several factors inherent to the site of application, such as the vaginal pH, the enzymatic activity, the vaginal microflora, the cyclical changes and the composition and characteristics of the vaginal fluid. Currently there is a wide variety of pharmaceutical systems for vaginal administration, from the most traditional such as solutions, ointments, creams, gels and vaginal tablets, to the most recent such as vaginal rings, vaginal films and nanossistems. Among the various systems, mucoadhesive formulations appear to be the most promising ones in replacement conventional pharmaceutical forms, since they allow an increase in the residence time of the drug at the site of application, with consequent increase of its therapeutical efficacy. The present dissertation consists in a bibliographical review of the state of the art of the main non conventional pharmaceutical systems for vaginal administration, among stand out cyclodextrins, microspheres, microemulsions, dendrimers, vaginal film, vaginal ring, liposomes and polymeric nanoparticles. For a better understanding of the mechanism of action, a brief review of the anatomy and physiology of the vagina was initially made.
Regarding the administration routes of drugs, the oral route has always been one of the most used. However, many researchers have been exploring the use of safe administration routes and considered more effective delivery systems to administrate drugs which have limited oral absorption or undergo early metabolization. In this context, the drug vaginal administration has been well explored in recent years. The vaginal mucosa presents several advantages such as easy accessibility, a high specific surface which allows local or systemic action, high vascularization and permeation to certain drugs, avoiding the hepatic first pass effect. However, the formulations for vaginal administration should take in account several factors inherent to the site of application, such as the vaginal pH, the enzymatic activity, the vaginal microflora, the cyclical changes and the composition and characteristics of the vaginal fluid. Currently there is a wide variety of pharmaceutical systems for vaginal administration, from the most traditional such as solutions, ointments, creams, gels and vaginal tablets, to the most recent such as vaginal rings, vaginal films and nanossistems. Among the various systems, mucoadhesive formulations appear to be the most promising ones in replacement conventional pharmaceutical forms, since they allow an increase in the residence time of the drug at the site of application, with consequent increase of its therapeutical efficacy. The present dissertation consists in a bibliographical review of the state of the art of the main non conventional pharmaceutical systems for vaginal administration, among stand out cyclodextrins, microspheres, microemulsions, dendrimers, vaginal film, vaginal ring, liposomes and polymeric nanoparticles. For a better understanding of the mechanism of action, a brief review of the anatomy and physiology of the vagina was initially made.
Description
Keywords
Sistemas farmacêuticos Administração vaginal Sistemas de administração vaginal Pharmaceutical systems Vaginal delivery Drug delivery system