Preparation and characterization of tadalafil-loaded hydrogel: An in-vivo evaluation of wound healing activity

Tadalafil (TD) is a phosphodiesterase type 5 (PDE-5) inhibitor that has gained attention for its wound healing properties. In this study, a TD-loaded hydrogel was prepared and characterized, and its wound-healing efficacy was evaluated. After preparing the TD hydrogel, its physicochemical properties such as viscosity, pH, drug-loading capacity (DL%), in vitro release behavior, and stability were characterized. Moreover, in vivo studies were performed to evaluate hydroxyproline (HP) and the wound healing efficacy of 1, 1.5, 3% (w/w) TD hydrogels in New Zealand rabbits. Histopathological analysis was also performed using hematoxylin and eosin (H&E) staining. We successfully prepared a TD hydrogel with high stability. The results of the in vivo experiments on full-thickness wounds showed that the 1.5% TD hydrogel with a pH of 5.81 ​± ​0.421, viscosity of 12,435 ​± ​63, drug-loading capacity of 91.73 ​± ​1.482%, and drug release rate of 88% was superior to other formulations when HP level was increased, which decreased the time required for wound healing; this was corroborated by the histological analysis. Thus, the TD hydrogel formulation prepared in this study is a promising topical therapeutic agent for wound healing.