Rachmatya W. Tuna. 2023. The Effect of HPMC and Na-CMC Polymer Combination on Physical Properties of Astaxanthin Nanoemulsion Patches. Undergraduate Thesis. Undergraduate Program, Department of Pharmacy, Faculty of Sports and Health, Universitas Negeri Gorontalo. The Principal Supervisor is Dr.rer.med. Robert Tungadi. M.Si., Apt., and the co-supervisor is Nur Akn Thomas, S.Si., M.Si., Apt Astaxanthin is a xanthophylls carotenoid group compound found in various microorganisms and marine animals with biological activity as antioxidants. However, the utilization of the potential benefits of astaxanthin in medicines is still limited because the solubility of astaxanthin in water is very low which leads to low bioavailability. This study aimed to observe the effect of HPMC and Na-CMC polymer combination. This research began with the manufacture of astaxanthin nanoemulsions which then characterized the particle size through a Particle Size Analyzer and evaluated the pH and viscosity of astaxanthin nanoemulsions. The particle size of the three astaxanthin nanoemulsion formulas ranged from 10,2 nm-12,8 nmwith PDI values of 0,1055-0,5575. Furthermore, the finest formula of the nanoemulsion was formulated in a patch preparation with three variations in Na-CMC concentrations of 0,5%, 1%, and 1,5% combined with 3% HPMC as a polymer. The three formulas evaluated included the organoleptic test, pH test, weight uniformity test, patch thickness test, drying shrinkage test, and folding resistance test. The test results revealed that the HPMC and Na-CMC polymers affected the formulation of astaxanthin nanoemulsion patches, where the addition of Na-CMC on each formula affected evaluation testing, particularly increased thickness, patch weight, and drying shrinkage. The three formulas of the patch preparation have fulfilled the evaluation terms of organoleptic, pH, weight uniformity, patch thickness, % drying shrinkage, and folding resistance. To sum up, there was a significant effect between the combination of HPMC and Na CMC polymer and the physical properties of astaxanthin nanoemulsion patch. preparation particularly in weight uniformity test, patch thickness test, and % drying shrinkage.