A Comprehensive Review on Hydrogel Based Topical Drug Delivery System

Large volumes of biological fluids can be absorbed by hydrogels, which are three-dimensional, insoluble polymer networks. They can be formed through chemical (covalent) or physical (secondary force) cross-linking and may be derived from natural or synthetic polymers. Their key features—swelling ability, mechanical strength, and biocompatibility—greatly influence their performance. They are commonly used in wound dressings, tissue engineering, contact lenses and drug delivery systems because hydrogels contain a large amount of water and closely resemble natural tissue. They can also be designed to respond to environmental stimuli such as temperature or pH, making them highly versatile materials in biomedical applications.