Why kojic acid dipalmitate become popular than kojic acid in cosmetic filed

1. What Is Kojic Acid Dipalmitate?

Cas No.: 79725-98-7

Molecular formula: C38H66O6

Molecular weight: 618.93

Kojic acid dipalmitate is a derivative of kojic acid and a fatty acid (palmitic acid), and one of the many active we use to alleviate the problem of hyperpigmentation.

It is an off-white powder with excellent anti-oxidant ability.

It is one of our most hot-selling cosmetic ingredients.

People use Kojic acid dipalmitate widely in cosmetics to lighten and even out skin tone and to treat acne scars, sunburns, and age spots.

It is regarded as one of the most popular and effective skin-whitening agents in the cosmetic industry.

Studies have found that after coupling kojic acid palmitate with glucosamine derivatives, its whitening effect will increase exponentially.

Kojic acid palmitate is superior to kojic acid in skin whitening and you check their differences below.

2. Kojic acid dipalmitate vs kojic acid

Kojic acid palmitate is a derivative of kojic acid and it is regarded as the best kojic acid version in the kojic acid family so far.

From the above, you can see their structural differences.

Here we skip their differences in physical and chemical properties such as molecular weight, molecular formula, etc, we only compile their differences when they are used in cosmetics as below:

#1 Different water solubilities

Kojic acid dipalmitate is a lipid-soluble substance insoluble in water or ethanol.

If you want to use it for skin-whitening, you must choose oil-based lotions or serums, or it will not be dissolved and absorbed by your skin to achieve whitening effects.

While Kojic acid is insoluble in lipids but soluble in water.

So mix kojic acid into your water-based serums or lotions.

#2 Pigmentation and melasma eliminating effects

Clinical trials have shown that the efficiency of kojic acid dipalmitate is over 50%, and the total effective rate is over 90%, but the effect of kojic acid is much lower.

#3 Whitening efficacy

Kojic acid ester has a stronger inhibitory effect on melanin production than kojic acid.

For example, kojic acid dibutyrate ester is twice powerful in stopping melanin production as kojic acid

#4 Stability

As an ester, Kojic acid dipalmitate is more stable than kojic acid.

Because there are two active hydroxyl groups in kojic acid within kojic acid, kojic acid is easier to be oxidized to change color or its character, while kojic acid dipalmitate is more difficult to be oxidized to be something else when these two hydroxy groups are protected, then it is less likely for kojic acid palmitate to go yellow or bad when exposed to air, heat, light, and moisture.

Plus, kojic dipalmitate will not chelate with many metal ions like kojic acid does within the cosmetics, so kojic dipalmitate lotion will not easily go yellow or change color compared with lotions made of kojic acid.

Plus, kojic acid is not stable in an alkaline environment due to its acid nature, while kojic dipalmitate is relatively more stable when the environmental PH value is between 3 to 10.

#5 Compatibility with other whitening ingredients

Kojic acid palmitate is almost compatible with any preservatives and sunscreens used for cosmetics.

It blends well with Vitamin C, alpha arbutin, and Vitamin C derivatives to get a better-whitening effect.

Research has shown that the combined-whitening effect increased exponentially.

#6 Safety

As an ester, kojic acid palmitate is neutral to your skin.

But your skin will get itchy when exposed to a formula containing acid such as kojic acid, glycolic acid, etc.

Research has shown that Kojic acid solution is more likely to cause itching or irritation to your skin.

#7 Cost and Purity

After so many advantages of dipalmitate over kojic acid, kojic acid powder has its advantages.

Kojic acid is cheaper, it costs about 1/9 of dipalmitate powder.

Also, the purity of kojic acid powder is 99% as min, and dipalmitate kojic acid purity is 98% as min.

3. How Is Kojic Acid Dipalmitate Manufactured?

First, we obtain palmitoyl chloride through PC13 and palmitic acid reactions.

Then we let palmitoyl chloride react with kojic acid to obtain the crude product, and then wash and recrystallize it to obtain pure kojic acid dipalmitate crystals

(1) Synthesis of palmitoyl chloride

Add palmitic acid to a three-neck flask, and dissolve it with CC14. Slowly drop PC13 into the flask by a funnel.

We start the reaction at a low stirring speed.

Later when the reaction begins, we let them react at 54~55 degrees celsius for several hours.

later we heat it to 60 degrees and let the reaction goes on for another hour, then we stop the reaction and remove H3P03.

(2) Synthesis of kojic acid dipalmitate

First, dissolve kojic acid in an acetone/pyridine solution in a three-neck flask, then slowly drip the palmitoyl chloride by a funnel and let them react at room temperature.

At the end of the reaction, we wash the target solid with cold water 3 times and filter it on a Brinell funnel.

At last, we recrystallize and dry it under a vacuum to obtain white flaky crystals.

Results and conclusion:

(2.1) Water-free reaction conditions

PCl3 is a pungent-smelling liquid, which will decompose to produce white smoke when exposed to water.

The yellow by-product in the flask during the reaction is phosphoric acid.

Because of the active nature of palmitoyl chloride and PCl3, we must carry out the entire experimental procedure under dry conditions.

(2.2) Different molecular ratios.

When the molar ratio of n(palmitic acid)/n (PCl3) is 1:2, the reaction has the highest conversion rate and the purity of palmitoyl chloride is estimated to be 95% as min.

(2.3) The reaction temperature.

When the reaction temperature is lower than 55 degrees Celsius, the chlorination reaction cannot be carried out completely, and only when the temperature is higher than 55 degrees and the final reaction temperature reaches 60 degrees, the chloride reaction tends to reach completion.

Thus, a suitable reaction temperature for the preparation of palmitoyl chloride is 55-60 degrees, and the final reaction temperature must be raised to 60 degrees Celsius and maintained for 1 hour to get the highest yield.

4. How To Dissolve Kojic Acid Dipalmitate Powder?

#1. As kojic acid dipalmitate is insoluble in water, it is difficult for you to mix it directly in water-based cosmetics.

Even when you manage to blend in some, it is easy for it to form crystal precipitates afterward.

To solve this crystalization problem, you can add isopropyl palmitate or isopropyl myristate to the oil phase containing kojic acid dipalmitate, heat the oil phase to 80 ℃, and keep it warm for 5 minutes until kojic acid dipalmitate is completely dissolved.

Then add the oil phase to the water phase and emulsify for about 10 minutes.

The pH value of the end products obtained is usually between 5.0 and 8.0.

The recommended dose of kojic acid dipalmitate in cosmetics is 3-5%.

#2. Or you can mix kojic acid dipalmitate powder directly into your creams to get 3~5% whitening creams.

Take 3~5g pure kojic acid dipalmitate powder and mix it in a 100ml-cream by stirring and shaking till all is dissolved.

You can also dissolve it in white oil first before mixing the oil into a cream formulation.

5. Benefits

Stable from pH 3 to 10

Does not complex with metal ions and will not change color

Light and heat stable

Compatible with most cosmetic ingredients.

6. Applications

Sunscreens and after-sun products

Makeup products

Skin lightening products

Anti-aging products

Creams and lotions

7.How to use it?

Beginner: Add up to 1 tube to 4 oz of your favorite base cream.

Advanced: This ingredient is recommended for use at up to 5% in formulations. Do not use at a stronger concentration. For best results, dissolve the powder in a white oil (such as cosmetic grade mineral oil or paraffin liquid) before adding to a cream or oil-based formulation. We recommend using this ingredient in formulations with a pH range of 4-7.