Background
Quercetin acts as an antioxidant, anti-inflammatory, wound healing, and anti-aging so quercetin can be used as a topical preparation. However, it has low solubility in water at 0.01 mg/ml at 25oC. Increasing the solubility of quercetin in water was done by the addition of surfactants.
Conclusion
Polysorbate 80 can increase the solubility of quercetin in citrate buffer pH 4.5±0.2 higher than Polysorbate 20.
Methods
The surfactants Polysorbate 80 and Polysorbate 20 differ in their alkyl chain length. Polysorbate 80 has an alkyl chain length of 18, while Polysorbate 20 has an alkyl chain length of 12. The concentrations of surfactant are above, below, and at the critical micelle concentration (CMC) values. The concentrations of quercetin were determined at the maximum wavelength by spectrophotometric method.
Objective
This study compared the solubility of quercetin in Polysorbate 20 (P20) and Polysorbate 80 (P80) in a citrate buffer medium pH 4.5±0.2.
Results
The results of the quercetin solubility test without surfactant were 3.89±0.59 mg/L. The results of the quercetin solubility test by adding Polysorbate 20 at a concentration of 42.0 ppm; 57.5 ppm; and 73.0 ppm were 3.62±0.72, 4.04±0.23 and 8.35±1.97 mg/L, respectively. While the solubility of quercetin by adding Polysorbate 80 at a concentration of 4.0 ppm, 11.5 ppm, and 19.0 ppm was 11.15±0.72, 11.37±1.23 and 14.17±1.96 mg/L, respectively. The solubility of quercetin is greater after the addition of surfactant Polysorbate 20 only at the concentration above the CMC value and the solubility of quercetin is greater with the addition of surfactant Polysorbate 80 at all concentrations. Surfactant Polysorbate 20 increases the solubility of quercetin in citrate buffer pH 4.5±0.2 only at concentrations above the CMC value of 2.14 times. Polysorbate 80 can increase the solubility of quercetin in citrate buffer pH 4.5±0.2 at concentrations below, at, and above CMC by 2.87, 2.92, and 3.63 times, respectively.