BIOCOMPATIBILITY OF ASTAXANTHIN GEL: CHARACTERIZATION, ANTIOXIDANT, AND SKIN SAFETY ASSESSMENT

Objective: Astaxanthin is a natural compound that possesses a strong antioxidant activity. This substance demonstrates huge potential for both maintenance and therapy. Previous studies suggested this substance could be used as gel therapy for oral cavity ulcers. This research aims to explore the characterization and antioxidant properties of gel formulations or conducted skin safety assessments to evaluate the biocompatibility of astaxanthin gel. Methods: Characterization assessment of astaxanthin gel at concentrations of 0.1%, 0.5%, 1%, and 5%, measuring material viscosity, pH, homogeneity, spreadability, adhesiveness, and organoleptic qualities. Antioxidant assessment was carried out in vitro using the DPPH technique by observing the value of antioxidant inhibition (IC50). The acute skin sensitivity and irritation tests were performed in vivo, and the effects were for 14 days. The result of observing clinical changes and the death of rats were noted. The irritation test is observed from the redness on the skin and scored using the Draize-FHSA scoring system and primary irritation index (PII). Results: Astaxanthin gel 0.1%, 0.5%,1%, and 5% have a viscosity value of 3250-3500, pH 7.7-7.85, homogeneous, with spreadability of 3.1-3.5 cm. Astaxanthin gel 1% has the maximum viscosity, pH range, and spreadability with adhesion duration is 3 min and 7 seconds. The IC50 test showed a value of<50 ppm. The gel exhibits no alterations in the skin, fur, eyes, or behavior of rats. The redness and edema score results in all groups are zero, indicating no irritation. Conclusion: The outcomes of this experiment show that 1% astaxanthin gel has the highest antioxidant impact compared to other concentrations. The acute skin toxicity and irritation tests revealed that this gel is acceptable in all concentrations.