Author: Sam Maher, Luca Casettari ,and Lisbeth Illum
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, absorption modifying excipients; nasal delivery; ocular delivery; oral delivery; permeation enhancers; transmucosal permeation; vaginal delivery, natural extracts from Aloe vera interact with intestinal epithelial cells. The study found whole leaf and gel extracts of Aloe vera contain considerable quantities of the acidifiers, citric acid and malic acid, which have previously demonstrated enhancement action, Extracts caused a partial reduction in TEER and a two- to three- fold increase in permeation of fluorescein isothiocyanate (FITC) dextran 4 kDa (FD4) in Caco-2 monolayers. Confocal analysis of monolayers showed that FD4 was localized at the paracellular space, and that there was disruption of filamentous actin, a scaffolding protein that holds tight junctions in place, Ocular drug delivery can broadly be considered in terms of topical, peri-ocular, or intra-ocular administration. The most common route of administration is topical delivery where medicaments are directly applied to the cornea, sclera and conjunctiva for local or regional actions. Delivery to peri-ocular or intra-ocular targets via either the cornea or blood retinal barrier is difficult even for highly permeable actives. The cornea is a widely accessible epithelial surface, although drug transport across this barrier is arguably more challenging than via other epithelia, Nasal administration is among the most successful approaches for the systemic delivery of macromolecules. A number of small peptides are marketed in intranasal formulations, application of bioenhancers in buccal, nasal, oral and pulmonary routes of administration, and provides information on source, model of action, test delivery model and payloads, oral and nasal routes, and to a lesser extent via pulmonary, buccal, ocular and vaginal routes
