Development of Cross-Linked Gelatin Hydrogel Films Using Tannic Acid as Anti-Aging Active with Skin Care Potential

Hydrogel films based on gelatin, glutaraldehyde and glycerol are widely reported in many studies with applications focused on food packaging, microencapsulation and release of active drugs. Thus, this study used this composition to produce hydrogel films and brought as a novelty the incorporation of tannic acid (TA) as anti-aging active, due to its great antioxidant capacity. The presence of TA in the hydrogel films was verified by the C-O stretch absorption band at 1020 cm-1, as well as by its thermal degradation between 200 and 300 ºC. Furthermore, the presence of this active compound, which influenced the physical, morphological and mechanical properties of the film, was also confirmed by qualitative release tests. Additionally, the mechanical properties of the HT2 hydrogel film showed acceptable values of elongation at break (28.9 ± 3.1%) and Young modulus (6.4 ± 1.1 MPa), suggesting that this film has the potential to be applied in skin care routines.