Study into the hydrolysis of polyhexamethylene guanidine hydrochloride

The development of new preparations for managing skin lesions is a task requiring a complex research approach. Thus, one promising direction consists in the creation of new bases for wound-healing drugs for external application. Chemical compounds that can be used as such bases include polymeric hydrogels, representing spatially cross-linked macromolecules that swell in a solvent. This property provides an opportunity to load hydrogels with drugs of both synthetic and herbal origin. A search for a gel-forming polymer acting not only as a drug carrier, but also as a healing agent presents a relevant research task. In a previous work, the authors obtained polyhexamethylene guanidine hydrochloride hydrogels by crosslinking terminal amino groups with formaldehyde. The conducted studies of the wound-healing capacity of the obtained hydrogels and compositions on their basis confirmed their comparability with such widely-used agents, as levomecol, bepanthene, etc. In addition, the obtained compositions were found to exhibit their own activity. Therefore, hydrogels based on polyhexamethylene guanidine hydrochloride can be used as a promising platform for drug design. In this work, the destruction products released during hydrolysis of the hydrogel under study were investigated. IR and UV spectroscopy methods were applied to evaluate the concentration of hydrogel destruction products over time. A mechanism of hydrogel destruction yielding the initial polyhexamethylene guanidine hydrochloride and formaldehyde in a gem-diol form is proposed.