PENGGUNAAN KUBIS UNGU (Brassica oleracea L. var. capitata f. rubra) SEBAGAI BAHAN KOSMETIK ANTIOKSIDAN : OPTIMASI FORMULA GEL MENGGUNAKAN SIMPLEX LATTICE DESIGN DAN PENGUJIAN AKTIVITAS ANTIOKSIDAN SECARA IN VITRO

Rima Yulia Senja, Dr. Akhmad Kharis Nugroho, M.Si.,Apt

2014 | Tesis | S2 Ilmu Farmasi

Telah dilakukan penelitian tentang penggunaan ekstrak kubis ungu (Brassica oleracea L. var. capitata.f.rubra) sebagai bahan kosmetika antioksidan: optimasi formula gel menggunakan metode Simplex Lattice Design dan pengujian aktivitas antioksidan secara in vitro. Kubis ungu diekstraksi dengan soxhletasi. Penentuan formula optimum gel antioksidan ekstrak kubis ungu dengan metode Simplex Lattice Design menggunakan software Design-Expert® versi 7 (DX7) dan pengujian aktivitas antioksidan gel ekstrak kubis ungu dilakukan secara in vitro menggunakan metode spektrofotometri Ultra Violet. Stabilitas formula optimum gel dilihat melalui perbandingan sifat fisik pada awal pembuatan dan setelah penyimpanan 4 minggu menggunakan ANOVA, dengan taraf kepercayaan 95%. Hasil pengujian menunjukkan bahwa IC50 ekstrak kubis ungu sebesar 168,78±5,15μg/mL. Formula optimum gel antioksidan ekstrak kubis ungu diperoleh pada proporsi metolose 3,883%, propilenglikol 13,5%, Tween 80 1,117%. Hasil evaluasi formula optimum gel ekstrak kubis ungu adalah luas permukaan sebar gel 38,99±3,27cm2; viskositas gel 295,56±1,93 dPa.S dan perubahan viskositas 3,89±0,96%. Dari hasil analisis statistik uji-t satu sampel disimpulkan bahwa tidak ada perbedaan antara harga prediksi software dengan hasil observasi (p>0,05). Hasil pengujian IC50 gel ekstrak kubis ungu adalah 257,25±0,35 μg/mL. Hasil pengujian stabilitas fisik formula optimum gel antioksidan ekstrak kubis ungu mengalami penurunan pH pada penyimpanan setelah 4 minggu (p<0,05).

A Study on the using of Red cabbage (Brassica oleracea.L. var. capitata. f. rubra) extract as antioxidant cosmetics material in gel formulation optimization had been performed based on Simplex Lattice Design (SLD) method. Antioxidant activity of the formula was also evaluated in vitro assay. The Red cabbage was extracted using soxhletation and followed by optimization of Red Cabbage extract in antioxidant gel preparation using SLD method using Design-Expert® software version 7 (DX7) and determination of its IC50 using UV-Spectrophotometry. Stability of formula gel optimum seen through comparison of physycal properties at the beginning and after four week of storage using ANOVA, with a 95% confidence level. The result showed that IC50 of Red Cabbage extract 168,78±5,15 μg/mL. Optimum Red cabbage extract gel formula obtained in the proportion of metolose 3,883%, propilenglikol 13,5%, Tween 80 1,117%. The evaluation results of the dispersive surface area, viscosity and viscosity change were respectively 38,99±3,27cm2; 295,56±1,93 dPa.S and 3,89±0,96%. One sample t-test was conducted to determine the differences between the predictions of the physical properties of the optimum formula that is determined using the software with the experimental results. The antioxidant activity result showed that IC50 values of Red cabbage extract gel was respectively 257,25±0,35 μg/mL. Optimum gel formula has decreased pH after four week of storage (p<0,05).

Kata Kunci : Kubis ungu, gel, optimasi, antioksidan