Sambiloto leaves (Andrographis paniculata (Burm.f.) Wall. Ex. Nees) nanoemulsion preparations: Optimization of Tween 80 and PEG-400 concentrations as photoprotective agents

Sambiloto leaf (Andrographis paniculata (Burm.f.) Wall. Ex Ness) has the potential to be employed as a photoprotective agent due to its high antioxidant content in the form of quercetin and andrographolide. The nanoemulsion preparations can boost the photoprotective activity of sambiloto leaf extract due to its deepest penetration. This study aims to determine the optimum Tween 80 and PEG-400 concentration in the Sambiloto leaf extract nanoemulsion preparation using the factorial 22 design method through Design Expert 12® on pH response, specific gravity, viscosity, and percent transmittance. The optimum formula was tested for sun protection factor (SPF) and DPPH Radical Scavenging activity (IC50). The amounts of andrographolide and quercetin detected in the sambiloto leaf extract were 3.411% and 3.272%, respectively. The optimum formula for nanoemulsion preparations is at Tween 80 and PEG-400 concentrations of 15% and 25%. The optimum Sambiloto leaf extract nanoemulsion formula had a globule size of 172.433±24.312 nm, a PDI of 0.245±0.060, and a zeta potential of -18.100±0.755 mV. The optimum formula for sambiloto leaf nanoemulsion has an SPF value of 44.427 ± 0.081 and an DPPH Radical Scavenging activity (IC50) of 124.863 ± 4.045 ppm. The cycling test showed no significant difference (p>0.05) on organoleptic parameters, pH, specific gravity, and percent transmittance. Based on the results obtained, the optimum formula of Sambiloto leaf extract nanoemulsion has high potential as a photoprotective agent with good globule characteristics and stability.