Hydrogels for localized drug delivery: A special emphasis on dermatologic applications.

Skin disease treatment is a complex and time-consuming process due to the complex etiology, numerous side effects of conventional therapies, and difficulties in determining primary causes of the disease. Superficial wounds are often easy to treat. However, treatment of severe wounds caused by burn is challenging for clinicians. Optimum therapeutic benefits are based on the site-specific delivery of medicaments at the right time for a prolonged duration. Systemic toxicity and frequent dosing are the major challenges associated with the use of conventional therapeutics. Hydrogels are material of choice for drug delivery because of their high biocompatibility and ability to hold and release therapeutic agents. The number of hydrogels available for use in cosmetology and dermatology continues to grow during the past 1-2 decades. However, new hydrogel materials with high biocompatibility, antibacterial properties, and the ability to stimulate skin regeneration processes are in high demand. These are three-dimensional networks, which absorb a large amount of biological fluids and water. Hydrogels can be used as a biosensor, carrier systems for cells, drug delivery carriers especially for topical applications and in contact lenses. Hydrogels are highly porous carriers containing about 90% water. Stimuli-responsive hydrogels cause a change in network structure that is completely reversible in nature. The present review describes the applications of hydrogels in pharmaceutical formulations with a special emphasis on the treatment of dermatologic conditions such as acne, psoriasis, and mycosis.