Daun sirih diketahui mengandung banyak polifenol yang memiliki aktivitas antioksidan kuat sehingga dapat menghambat pembentukan radikal bebas ROS (Reactive Oxygen Species) yang merusak kulit. Ekstrak daun sirih diformulasikan dalam krim dengan konsentrasi 0,5%, 1%, dan 2%, dan divariasikan dengan penambahan BHT 0,05%, 0,075%, dan 0,1%. Penelitian ini bertujuan menguji stabilitas fisik dan menentukan pengaruh penambahan BHT pada aktivitas antioksidan krim setelah penyimpanan selama 8 minggu pada suhu kamar. Kestabilan fisik diuji dengan uji mekanik, cycling test, dan penyimpanan pada suhu rendah (7+2oC), suhu kamar (27+2oC), dan suhu tinggi (40+2oC).Hasil penelitian menunjukkan bahwa krim daun sirih 0,5%, 1%, dan 2% stabil pada penyimpanan suhu rendah dan suhu kamar, sedangkan krim daun sirih 2% tidak stabil pada suhu tinggi. Pada cycling test, krim daun sirih 2% tidak stabil, sedangkan pada uji mekanik ketiga formula krim tidak stabil. Aktivitas antioksidan diukur menggunakan metode peredaman DPPH. Hasilnya adalah krim yang diberikan BHT konsentrasi 0,1% bisa menjaga stabilitas antioksidannya selama penyimpanan 8 minggu pada suhu kamar. Tetapi, krim yang diberikan BHT konsentrasi 0,05% dan 0,075% belum mampu menjaga stabilitas antioksidannya selama penyimpanan 8 minggu pada suhu kamar.

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Betle leaf known contained high level of polyphenol, a strong antioxidant which inhibit ROS (Reactive Oxygen Species) formation causing skin damage, was formulated into cream with concentration of 0,5%, 1%, and 2% and varied with BHT concentration of 0,5%, 0,075%, and 0,1%. This research was designed to investigate the physical stability and the influence of BHT addition on the antioxidant activity of cream after 8 weeks storage at room temperature. Physical stability was tested with the centrifugal, cycling test, and storage at low (7+2oC), room (27+2oC), and high temperatures (40+2oC).The results showed that cream of 0,5%, 1%, and 2% was stable stored at low and room temperature, whereas at high temperature cream 2% did not. On cycling test, cream of 2% was not stable, all creams were not stable on centrifugal test. Measurement of antioxidant activity was done using DPPH radical scavenging method. The results showed that creams given BHT concentration of 0,1% to maintain the stability of antioxidant during 8 weeks of storage at room temperature. However, the creams that given BHT concentration 0,05% and 0,075% have not been able to maintain the stability of the antioxidant during 8 weeks of storage at room temperature.