Hydrogel Delivery Systems for Biological Active Substances: Properties and the Role of HPMC as a Carrier

Hydrogel delivery systems are popular dosage forms that have a number of advantages, such as ease of use, painlessness, increased efficiency due to prolongation of rheological, swelling and sorption characteristics, regulation of drug release, and stimulus sensitivity. Particular interest is shown in hydrogels of cellulose ether derivatives due to the possibility of obtaining their modified forms to vary the solubility, the degree of prolonged action, and the release of the active substance, as well as their widespread availability, affordability, and the possibility of sourcing raw materials from different sources. Hydroxypropyl methylcellulose (HPMC, "hypromellose") is one of the most popular cellulose ethers in the production of medicines as a filler, coating and carrier. Research on hydrogel carriers based on polymer complexes and modified forms of HPMC using acrylic, citric, and lactic acids, PVP, chitosan, Na-CMC, and gelatin is of particular interest, as they provide the necessary rheological and swelling characteristics. There is growing interest in medical transdermal hydrogels, films, capsules, membranes, nanocrystals, and nanofibers based on HPMC with the incorporation of biologically active substances (BASs), especially those of plant origin, as antibacterial, wound-healing, antimicrobial, mucoadhesive, anti-inflammatory, and antioxidant agents. The aim of this article is to review modern research and achievements in the field of hydrogel systems based on cellulose ethers, particularly HPMC, analyzing their properties, methods of production, and prospects for application in medicine and pharmacy.