Hydrophobic polymers are insoluble in water or other polar solvents and are used as coatings, adhesives, fibers, films, and engineering plastics, as well as biomedical polymers for vascular grafts, implants, and ophthalmic applications.
The use of hydrophobic polymers in drug delivery applications has increased dramatically in recent years. These materials offer particular promise for controlled/sustained drug release, thereby enhancing the pharmacological action of the drug.
These controlled/slow release drug delivery systems can offer considerable clinical and economic advantages. Both the physicochemical properties of the hydrophobic polymer and the design of the drug delivery system affect the mechanism of drug diffusion from the polymer system.
Fig 1. Commonly used hydrophobic polymer.
There are numerous examples of hydrophobic polymers. The following is a brief description of a few of them:
- Acrylic Polymers: Acrylic resins are made up of polymers such as acrylic, acrylonitrile, acrylamide, and maleic anhydride. Rigid, flexible, hydrophilic, or hydrophobic homopolymers and copolymers Polymers are commonly employed in coatings, adhesives, and fibers because they are thermoplastic and can be easily transformed to the appropriate shape through thermal processing.
- Ether Polymers: Ether polymers are often flexible and provide impact resistance in addition to their other qualities. Many polyethers are utilized to make greater molecular weight polymers because they feature functional groups at their chain ends. As a result, they're also known as macromolecular monomers, and they're often utilized to make polyesters and polyurethanes.
- Fluorocarbon Polymers: Hydrophilic and hydrophobic materials do not "wetted" these polymers. They have a very low coefficient of friction and are chemically and thermally resistant. Copolymers are less difficult to melt than poly(tetrafluoroethylene).
- Polystyrene Polymers: As films, foams, and structural components, polystyrene and its copolymers have shown to be useful. To increase physical qualities and generate thermoplastic elastomers, copolymers with diene monomers are cross-linked. Polystyrene films have a high refractive index and are highly transparent to visible light.
- Poly(vinyl chloride) Polymers: To improve the rheology of melt processing, poly(vinyl chloride) is frequently heavily plasticized. Because of its sensitivity to UV and high-temperature deterioration, stabilizers are frequently used.
- Poly(N-vinylpyrrolidone) (PVP) Polymers: PVP is a polar polymer with good adhesive and film-forming capabilities. It's extensively employed in the creation of hair gels and hand creams, as well as in the textile sector, due to its affinity for numerous colours.
- Guo X, et al. (2016). "Polymer-Based Drug Delivery Systems for Cancer Treatment." Journal of Polymer Science Part A Polymer Chemistry. 54(22): 3525-3550.