22 - Polysaccharide hydrogel films/membranes for transdermal delivery of therapeutics

Abstract

A hydrogel normally consists of a natural polymer and forms a three-dimensional network of hydrophilic polymeric chains. Hydrogels swell by absorption of a large amount of water without dissolution. Additionally, hydrogels indicate exceptional structural and mechanical characteristics that are comparable to those of the skin extracellular matrix (ECM) and tissues. These properties can make hydrogels appropriate biomaterials for application as scaffolds in the development of drug delivery systems, therapeutics, tissue engineering, imaging, and medical devices. Natural polysaccharides are commonly applied to deliver therapeutics because they are very biocompatible and biodegradable and are developed as complexes/conjugates with peptides, proteins, and various biomacromolecules. The most extensively studied polysaccharides include chitosan, sodium alginate, hyaluronic acid, and chondroitin sulfate. These polysaccharides are usually combined with other polymers to provide the preferred biochemical properties. The drugs used in film forming polymers for transdermal drug delivery must have suitable features and do not show dependencies to the dosage form. Drugs utilized in polymeric systems are commonly extremely potent and can quickly permeate the skin, but they do not cause skin irritation and are quite stable against enzymes existing in the epidermis. This chapter presents the most substantial recently reported findings using chitosan, hydroxyethylcellulose, carboxymethyl cellulose, gelatin, gellan gum, guar gum, acacia gum, pectin, hyaluronic acid, chondroitin sulfate, collagen, alginate, and smart hydrogels for transdermal drug delivery. In addition, the chapter presents our research results on the development of electrospun nanofibrous three-layered chitosan-polyethylene oxide/polylactic acid/chitosan-polyethylene oxide (CS-PEO/PLA/CS-PEO) mats containing green tea (GT) extract.