Tara and Red Algae Biopolymer as a Film-Forming Substance for Hair Protection

Considering the impact of environmental aggressors on hair health, the biopolymer derived from tara (<i>Caesalpinia spinosa</i>) and red algae (<i>Kappaphycus alvarezii</i>) can be applied in the development of hair care formulations due to its film-forming properties. Thus, the objective of this study was to develop hair care formulations containing the biopolymer and evaluate their rheological and texture properties, as well as their film-forming efficacy for hair protection. For this, shampoo, conditioner, and leave-in formulations were developed, and their texture and rheology profile were evaluated during 28 days. Efficacy was analyzed in terms of combability, smoothness, mechanical properties, diameter, and visual aspects before and after the treatment. Formulations with the biopolymer showed a reduced hysteresis area (by 48.17% for the conditioner and 88.09% for the leave-in), which is a rheological parameter directly associated with film formation. In addition, texture parameters decreased, which can improve the sensory properties. The biopolymer interacted with hair keratin via hydrogen bonding, which resulted in a 10.40% reduction in the tensile strength and a 15.85% increase in the fiber diameter. These interactions contributed to film formation on the hair surface, improving shine (by 29.42%) and smoothness (by 21.84%). These results showed that the biopolymer has potential to be applied as a film-forming substance in hair care products by reducing hair-environment interaction.