Transmucosal Absorption Enhancers in the Drug Delivery Field

Abstract

Drug delivery systems that safely and consistently improve transport of poorly absorbed compounds across epithelial barriers are highly sought within the drug delivery field. The use of chemical permeation enhancers is one of the simplest and widely tested approaches to improve transmucosal permeability via oral, nasal, buccal, ocular and pulmonary routes. To date, only a small number of permeation enhancers have progressed to clinical trials, and only one product that includes a permeation enhancer has reached the pharmaceutical market. This editorial is an introduction to the special issue entitled Transmucosal Absorption Enhancers in the Drug Delivery Field (https://www.mdpi.com/journal/pharmaceutics/special_issues/transmucosal_absorption_enhancers). The guest editors outline the scope of the issue, reflect on the results and the conclusions of the 19 articles published in the issue and provide an outlook on the use of permeation enhancers in the drug delivery field.

Nanosystems for the Encapsulation of Natural Products: The Case of Chitosan Biopolymer as a Matrix

“…On the other hand, chitosan coating in acidic conditions seems to increase the release of several drugs such as diclofenac. Thus, pH sensitivity of chitosan in combination with the nature of the drug [ 199 , 200 ] offers pH responsive chitosan nanostructures [ 201 , 202 , 203 ]. Furthermore, the viscosity of chitosan is a physicochemical property that also affects the release of the drug in the local area [ 201 ].…”

“…Thus, pH sensitivity of chitosan in combination with the nature of the drug [ 199 , 200 ] offers pH responsive chitosan nanostructures [ 201 , 202 , 203 ]. Furthermore, the viscosity of chitosan is a physicochemical property that also affects the release of the drug in the local area [ 201 ]. N. Üstündag˘-Okur et al [ 202 ] presented that high viscosity CCNs lead to slower drug release due to the higher viscosity of the gel layerwhich is formed when the nanoparticles and the release medium interface [ 203 ].…”

Recent Advances in the Excipients Used for Modified Ocular Drug Delivery

“…The administration of ocular drugs is mainly topical, but there are also periocular and intraocular administrations [ 18 ]. The topical route of administration is preferred over the systemic route due to several advantages.…”

Transmucosal drug administration as an alternative route in palliative and end-of-life care during the COVID-19 pandemic

“…Only a small number of drugs exhibit the desirable physicochemical properties to cross the mucosal epithelium effectively. In order to enhance drug absorption, penetration enhancers (or permeation enhancers) are commonly investigated in the development of transmucosal formulations to overcome the epithelial barrier, especially in intranasal, buccal, and to a lesser extent, rectal formulations [ 46 ]. Penetration enhancers promote drug absorption by increasing the permeability of epithelium.…”