Electronic Theses and Dissertation

Paparan radikal bebas berlebihan pada kulit wajah memicu stres oksidatif yang menyebabkan hiperpigmentasi, penuaan dini, dan kulit kering, sehingga diperlukan antioksidan topikal berbasis bahan alam. Penelitian ini bertujuan untuk menentukan aktivitas antioksidan ekstrak etanol bawang merah Gayo (Allium ascalonicum L.), memformulasikannya ke dalam sediaan masker gel peel off, serta mengevaluasi stabilitas fisik dan aktivitas antioksidannya. Ekstraksi dilakukan dengan metode maserasi etanol 96%, kemudian diformulasikan ke dalam empat formula masker gel peel off dengan variasi konsentrasi basis HPMC, yaitu F0 (HPMC 1,5% tanpa ekstrak) sebagai kontrol negatif, F1 (HPMC 1,5%), F2 (HPMC 2%), dan F3 (HPMC 2,5%) yang masing-masing mengandung ekstrak, lalu dievaluasi sifat fisik, stabilitas, serta aktivitas antioksidan ekstrak dan sediaan menggunakan metode DPPH. Ekstrak menunjukkan aktivitas antioksidan sangat kuat dengan IC₅₀ 17,65 ppm dan AAI 2,27. F0, F1, dan F2 memenuhi seluruh parameter evaluasi fisik dan stabil sebelum maupun sesudah cycling test, sedangkan F3 tidak memenuhi syarat waktu mengering setelah cycling test. Nilai IC₅₀ dan AAI sediaan yaitu F0 (IC₅₀ 125,02 ppm; AAI 0,32), F1 (IC₅₀ 34,12 ppm; AAI 1,17), F2 (IC₅₀ 50,90 ppm; AAI 0,79), dan F3 (IC₅₀ 56,66 ppm; AAI 0,71). F1 dengan IC₅₀ 34,12 ppm dan AAI 1,17 dikategorikan sebagai antioksidan sangat kuat dengan efektivitas optimal dibandingkan formula lainnya.

Kata kunci: Allium ascalonicum L., antioksidan, bawang merah Gayo, DPPH, masker gel peel off

ABSTRACT Excessive exposure to free radicals on the facial skin triggers oxidative stress, leading to hyperpigmentation, premature aging, and dry skin; therefore, topical antioxidants derived from natural ingredients are needed. This study aims to determine the antioxidant activity of Gayo red onion (Allium ascalonicum L.) ethanol extract, formulate it into a peel-off gel mask, and evaluate its physical stability and antioxidant activity. Extraction was performed using the 96% ethanol maceration method, followed by formulation into four peel-off gel mask formulations with varying HPMC base concentrations: F0 (1.5% HPMC without extract) as the negative control, F1 (1.5% HPMC), F2 (2% HPMC), and F3 (2.5% HPMC), each containing the extract. The physical properties, stability, and antioxidant activity of the extract and formulations were then evaluated using the DPPH method. The extract exhibited very strong antioxidant activity with an IC₅₀ of 16.75 ppm and an AAI of 2.27. F0, F1, and F2 met all physical evaluation parameters and remained stable before and after the cycling test, whereas F3 did not meet the drying time requirement after the cycling test. The IC₅₀ and AAI values of the formulations were as follows: F0 (IC₅₀ 125.02 ppm; AAI 0.32), F1 (IC₅₀ 34.12 ppm; AAI 1.17), F2 (IC₅₀ 50.90 ppm; AAI 0.79), and F3 (IC₅₀ 56.66 ppm; AAI 0.71). F1, with an IC₅₀ of 33.77 ppm and an AAI of 1.18, was categorized as a very strong antioxidant with optimal efficacy compared to the other formulations. Keywords: Allium ascalonicum L., antioxidant, Gayo red onion, DPPH, peel-off gel mask