5.5 Mechanisms of Action of Penetration
which penetration enhancers are assumed to advance mucosal absorption are as
§ Altering mucus rheology: Mucus establishes viscoelastic
layer of variable thickness that impact drug absorption. That goes without saying,
saliva coating the mucus layers likewise deters the absorption. Some permeation
enhancers act by diminishing the viscosity of the mucus and saliva.
§ Improving the mutability of lipid bilayer membrane:
The utmost acknowledged mechanism of drug absorption into buccal mucosa is the intracellular
route. Some enhancers disrupt the intracellular lipid packing by binding with
either lipid or protein components.
§ Working on the components at tight junctions: Some
enhancers play on desmosomes, a major constituent at the tight junctions. By disabling
the enzymatic barrier: These play by hindering the numerous peptidases and
proteases found in the buccal mucosa, by this means disabling the enzymatic
barrier. Moreover, variations in membrane mutability likewise modify the
enzymatic activity implicitly.
§ Improving the thermodynamic activity of drugs: Some
enhancers enhance the solubility of drug by this means changes the partition
coefficient. This results in an improved thermodynamic activity ensuing in
Anionic, cationic and nonionic types and bile salts are examples of
surfactants that improve permeability of drugs by perturbation of intercellular
lipids; however, chelators perform by meddling with the calcium ions. Fatty
acids play a role by improving fluidity of phospholipids and positively charged
polymers perform by ionic interaction with negative charge on the mucosal
surface. Chitosan displays more than a few advantageous properties like biodegradability,
biocompatibility and antifungal/antimicrobial properties in addition to its
potential bioadhesion and absorption enhancement.