The main problem with the use of extracts is that the active substance inside is trapped in a large extract/simplicia then it is difficult to penetrate the lipid membranes of body cells. The way to solve this problem is to reduce the particle size of the extract, one of which is by converting it into an extract suspension. The study was initiated by extracting waru leaves (Hibiscus tiliaceus) by remaceration method using methanol as a solvent. After that, the suspension of Hibiscus tiliaceus leaves extract was made by ionic gelation method. Then both (methanol extract and extract suspension) were measured for total flavonoid and phenolic content and antioxidant activity by UV-Vis spectrophotometry method. The purpose of this study was to compare the total flavonoid content, total phenolic content, and antioxidant activity of methanol extract and suspension extract of Hibiscus tiliaceus leaves. The results showed that the particle size of the methanol extract and the extract suspension were 1.509 ± 0.553 µm and 0.715 ± 0.390 µm, respectively. The total flavonoid content of the methanol extract was 3434.890 ± 0.008 µgQE/mL while the suspension extract was 409.891 ± 0.001 µgQE/mL. The total phenolic content of the methanol extract was 244352.685 ± 1016.713 µgGAE/mL while the suspension extract was 12068.316 ± 86.970 µgGAE/mL. The IC50 value of methanol extract was 58.564 ± 1.412 µg/mL while the extract suspension was 7917.333 ± 21.385 µg/mL. In conclusion, the total flavonoid content, total phenolic content, and antioxidant activity of the methanol extract were higher than the suspension extract.

Daun waru (Hibiscus tiliaceus) adalah salah satu jenis tanaman yang mengandung flavonoid dan senyawa fenolik alami serta bermanfaat sebagai antioksidan. Flavonoid dan fenolik dapat diekstraksi dengan optimal jika menggunakan pelarut ekstraksi yang sesuai. Penelitian ini bertujuan untuk mengetahui kadar flavonoid total, fenolik, dan antioksidan ekstrak daun waru menggunakan beberapa pelarut. Pengujian kadar flavonoid total dengan metode kolorimetri AlCl3, kadar fenolik total dengan metode Folin-Ciocalteu, dan kadar antioksidan dengan metode DPPH. Kadar flavonoid total ekstrak dengan pelarut metanol, etanol, dan air secara berurutan adalah 121,630 ± 2,014 µgQE/g; 133,190 ± 1,434 µgQE/g; 78,320 ± 1,799 µgQE/g. Kadar fenolik total ekstrak dengan pelarut metanol, etanol, dan air secara berurutan adalah 9.151,480 ± 58,969 µgGAE/g; 7.978,610 ± 84,845 µgGAE/g; 4.789,690 ± 14,576 µgGAE/g. Ekstrak dalam pelarut metanol memiliki aktivitas antioksidan sangat lemah (IC50 = 710,680 ± 3,747 µg/mL). Ekstrak dalam pelarut etanol memiliki aktivitas antioksidan sangat lemah (IC50 = 989,150 ± 0,798 µg/mL). Ekstrak dalam pelarut air memiliki aktivitas antioksidan sangat lemah (IC50 = 1.643,480 ± 1,828 µg/mL). Ekstrak etanol memiliki kadar flavonoid total tertinggi. Ekstrak metanol memiliki kadar fenolik total tertinggi dan aktivitas antioksidan sangat lemah..