Novel nanostructured supramolecular hydrogels for the topical delivery of anionic drugs

Cationic Supramolecular Hydrogels for Overcoming the Skin Barrier in Drug Delivery

“…Supramolecular gels formed with isomeric compound 1⋅2 Br can incorporate anionic drugs not only in the interstitial space of the gel but also inside the gel fibers . This was thought to be due to an electrostatic interaction between the positively charged gelator and the negatively charged drug.…”

“…Many gels are made out of polymer molecules, and they can be classified depending on the way the molecules attach to each other to form the fibers: they can be covalently bonded throughout the whole system to form a polymer (chemical gels), or they can be composed of smaller subunits that are attached to each other through weaker chemical forces such as hydrogen bonds, coulombic forces, and van der Waals interactions, among others (supramolecular gels) . The covalent attachment of chemical gels leads to the formation of an irreversible, robust material that can be useful in certain biomedical applications such as contact lenses; however, for drug delivery or other biomedical applications, supramolecular gels (also called physical gels) are more suitable because they are softer and non‐permanent . The majority of existing gels for cutaneous applications are supramolecular gels made out of polymeric subunits .…”

“…Interesting examples include supramolecular gels for which host–guest interactions induce self‐assembly only above a certain temperature and melt below it, as opposed to the majority of thermoreversible gels . Also, the use of bis‐imidazolium derivatives as LMWGs has been reported, but gel formation can also need the presence of additional solvents such as glycerol and octanol or ionic liquids …”

“…For instance, they were shown to form micelles and to deliver anionic drugs when they are stabilizing gold nanoparticles . These surfactants can also act as LMWGs and form supramolecular hydrogels for drug delivery . However, recently, all cases of drugs incorporated into cationic gels have been anionic, as the electrostatic attraction between the positively charged surfactant and the negatively charged drug was thought to be the interaction responsible for the behavior of the material, and these drugs displayed slow and sustained release.…”

Rationally Developed Organic Salts of Tolfenamic Acid and Its β‐Alanine Derivatives for Dual Purposes as an Anti‐Inflammatory Topical Gel and Anticancer Agent

“…[1][2][3][4][5] These types of viscoelastic materials are becoming more popular,m ainly because of their variousp otentiala pplications in electro-optics/photonics, [6,7] sensors, [8][9][10] cosmetics, [11] structuredirectinga gents, [12] conservation of art, [13] catalysis, [14] biomedical applications, [15][16][17][18][19][20] biomaterials, [21][22][23][24][25][26][27][28] and so forth. [1][2][3][4][5] These types of viscoelastic materials are becoming more popular,m ainly because of their variousp otentiala pplications in electro-optics/photonics, [6,7] sensors, [8][9][10] cosmetics, [11] structuredirectinga gents, [12] conservation of art, [13] catalysis, [14] biomedical applications, [15][16][17][18][19]…”