Abstract
Introduction: Light skin tone has been desired by many Asian women thus the search of effective depigmenting agent has been conducted by many researchers. Tranexamic acid, an anti-fibrinolytic drug, is now gaining popularity as a new depigmenting agent. However, studies on tranexamic acid have shown mixed result of its comparison to hydroquinone. Galactomyces ferment filtrate, niacinamide and alpha arbutin have been known of their depigmenting effect. Combined materials with different targeting mechanisms are used to enhance the effectiveness of the lighting agent
Objective: To compare the skin lightening effect of combination of tranexamic acid 3%, galactomyces ferment filtrate 2%, niacinamide 4%, and alpha arbutin 2% to hydroquinone 4%.

Methods: In this study, each of 30 participants applied a combination of tranexamic acid 3%, galactomyces ferment filtrate 2%, niacinamide 4%, and alpha arbutin 2% and hydroquinone 4% to the left forearm using a special patron. Subject then evaluated each week for four weeks. Clinical effects were evaluated using a chromameter including L* for skin brightness and a* for skin erythema. All measurements were taken three times, and the mean value was used. To assess the comparison of skin brightness score and pigmentation intensity between the two serum groups, the Independent T-test was used. As for assessing the change in scores based on measurement time in each serum group, Pearson's Correlation was used. The test results are significant if the value of p <0.05.

Results: Skin brightness (L*), as measured by chromameter, when sample first came (T0) on the area applied with serum combination of tranexamic acid 3 % got the average of brightness of skin 56,81, whereas in area applied 4% hydroquinone got average brightness of skin 55,66. In the last control of the area applied a serum combination of 3% tranexamic acid had an average skin brightness of 58.34 and the area applied with 4% hydroquinone serum had an average skin brightness of 57.48. There was a significant increase of skin brightness of the skin both in the area applied with tranexamic acid 3% (p <0.05) serum combination and in the area applied with hydroquinone 4% serum (p <0.01). The degree of decreased a* score was higher in combination of tranexamic acid 3% serum than hydroquinone serum, ie 0.314 compared to 0.221.

Conclusion: Serum combination of tranexamic acid 3%, galactomyces ferment filtrate 2%, niacinamide 4% and alpha arbutin 2% can be considered as a safe and effective option to increase skin brightness with no significant side effect.

Key words: Depigmenting, tranexamic acid, galactomyces ferment filtrate, niacinamide, alpha arbutin