Mucoadhesive drug delivery systems

Abstract

Drug actions can be improved by developing new drug delivery systems, such as the mucoadhesive system. These systems remain in close contact with the absorption tissue, the mucous membrane, releasing the drug at the action site leading to a bioavailability increase and both local and systemic effects. Mucoadhesion is currently explained by six theories: electronic, adsorption, wettability, diffusion, fracture and mechanical. Several in vitro and in vivo methodologies are proposed for studying its mechanisms. However, mucoadhesion is not yet well understood. The aim of this study was to review the mechanisms and theories involved in mucoadhesion, as well as to describe the most-used methodologies and polymers in mucoadhesive drug delivery systems.Uniterms: Mucoadhesion. Bioadhesion. Mucoadhesive systems. Drugs/delivery. O efeito de fármacos pode ser potencializado através do desenvolvimento de novos sistemas de liberação como os sistemas mucoadesivos. Estes sistemas permanecem em contato íntimo com o tecido de absorção, as mucosas, liberando o fármaco no local de ação, com o consequente aumento da biodisponibilidade, podendo promover efeitos locais e sistêmicos. A mucoadesão, atualmente, é explicada por seis teorias, a eletrônica, da adsorção, da molhabilidade, da difusão, da fratura e a mecânica. Para estudar seus mecanismos e quantificá-la, são propostas várias metodologias in vitro e in vivo. Porém, a mucoadesão ainda não é totalmente compreendida. Esse trabalho tem por objetivo revisar os mecanismos e as teorias envolvidas na mucoadesão, além de descrever as metodologias e os polímeros mais utilizados em sistemas mucoadesivos para liberação de fármacos.Unitermos: Mucoadesão. Bioadesão. Sistemas mucoadesivos. Fármacos/liberação.

Pullulan-based nanoparticles as carriers for transmucosal protein delivery

“…Morevover, the high surface-to-volume ratio displayed by nanoparticles increases drug loading capacity (de la Fuente et al, 2008a). Previous studies have demonstrated that nanoparticle contact with epithelial surfaces is maximised when they display a size within 50 and 500 nm (Desai et al, 1996;Jani et al, 1990) and a strongly positive zeta potential (Bogataj et al, 2003;Carvalho et al, 2010).…”

Organic cocoa extract -loaded surfactant-based systems intended to skin bioadhesion

“…This formulation exhibited characteristics of dilatant and reopetics fluids because of the increase in viscosity with increasing shear stress. This behaviour can be explained by filling the space between the particles with increasing shear stress: the sorting of particles promotes an increase in volume, causing an increase in melt strength, i.e., the viscosity (Carvalho et al, 2010a).…”

“…This formulation exhibited characteristics of dilatant and reopetics fluids because of the increase in viscosity with increasing shear stress. This behaviour can be explained by filling the space between the particles with increasing shear stress: the sorting of particles promotes an increase in volume, causing an increase in melt strength, i.e., the viscosity (Carvalho et al, 2010a).After the extracts were added to formulations H1E and H2E, no alteration was observed in the rheological behaviour of formulations. Thus, the addition of the extract did not influence the rheological behaviour of the formulations.…”

Mucoadhesive drug delivery system: an overview

“…Mucoadhesion is bond formation between pressure sensitive adhesive with biological substrate (mucosal layer). 2,3 In design and development of drug delivery systems mucoadhesive drug delivery has been considered as subject of great interest due to various merits. Prolongation of the residence time of the dosage form at the site of application by increasing intimate contact of the dosage form with the underlying absorption surface and leads to improved absorption properties with enhanced bioavailability of therapeutic agents is major quality of these systems.…”