kojic acid & glycollic acid cream stability problem

Skin

kojic acid & glycollic acid cream stability problem

Posted by amitvedakar on February 8, 2018 at 10:41 am

My skin cream formulation contains:
Active:
2% kojic acid
5% arbutin
10% glycollic aicd (70%)
0.1% vitamin E

Other ingredients:
Cetosteryl Alcohol, cm 1000, EGMS, Stearic acid, Carbomer940, Triethylamine,
Phenoxy ethanol, Di-sod. EDTA, Benzyl alcohol & silicon oil & Light Liquid Paraffin.

Cream color change started after 8 months form white to pale yellow.
After 18 months it started to become blackish.

Can anybody help?

Chizzy_Skinnergy replied 1 year, 7 months ago 7 Members · 13 Replies
13 Replies

amitvedakar

Member
February 8, 2018 at 10:43 am

It is packed in Lami. tube. & it has also a leakage problem.
em88

Member
February 9, 2018 at 2:23 pm

i guess kojic acid is not stable, probably an oxidation reaction happens.
Doreen

Member
February 9, 2018 at 4:02 pm

You’re not using broad spectrum preservatives. Fungi maybe? They come in all colours.
amitvedakar

Member
February 11, 2018 at 4:27 am

Thanks

Should I test that Blackish for microbes?
will it help to select preservative.
Doreen

Member
February 13, 2018 at 7:14 am

Yes, you can test it for microbes.
What is cm1000 and EGMS btw? I also don’t see water mentioned, what is the whole formula?
If benzyl alcohol and phenoxyethanol are your only preservatives, I would definitely add an anti-fungal, like paraben(s). Also benzyl alcohol and phenoxyethanol cover more or less the same, maybe you can do with only one of these +anti-fungal/yeast.
Bill_Toge

Member
February 13, 2018 at 11:00 pm

is the entire product going dark, or just the surface?

is the discoloration uniform, or does it just happen in irregular patches?

if possible, a photo would be very helpful
- Chizzy_Skinnergy
  
  Member
  April 24, 2023 at 2:23 am
  
  What is the difference if the discoloration is uniform or just sitting at the top?
Danger

Member
February 14, 2018 at 8:47 am

It’s because oxidation of kojic acid. You can use additional antioxidants. Try sodium hydrogen sulphites
Microformulation

Member
February 14, 2018 at 5:00 pm

Try the dipalmitate salt which is much more stable. On another note, I have done so many of these whitening products. A. That might be a bit aggressive and could have a great deal of inflammation. B. With the multiple raw materials, I imagine you could see some issues with incompatibilities, especially with those actives.

What is your final demographic and what is there Fitzpatrick rating?
amitvedakar

Member
February 15, 2018 at 4:30 am

Thanks sirs,

cm 1000 is ceto macrogol & EGMS - Ethylene Glycol Monostearate .
I use D.M. Water.
Will use of Sodium Metabisulphite increase stability?
The cream became brown first & than Blackish from the end of tube.
I have also added Methyl Paraben & Propyl papraben.
Image of cream as shown above.

Thanks again for your Interest & Suggestion.
em88

Member
February 15, 2018 at 8:01 am

omg, it looks like chocolate.
Probably the color is more darker at the end because is less cream.
That is an oxidation issue (I was right finally lol)
You can use Kojic Acid Dipalmitate instead of Kojic acid, it appears more stable.
https://www.in-cosmetics.com/__novadocuments/2888
“2. Light and Heat Stability
Kojic Acid Dipalmitate is light and heat stable, while kojic acid tends to oxidize over time”
amitvedakar

Member
February 15, 2018 at 9:19 am

Thank you all.
I am going to experiment with sodium metabisulphite & Dipalmitate.
em88

Member
February 15, 2018 at 9:53 am

You should avoid heat as well. Based on the ingredients you are using, you have a hot emulsion process. Try adding kojic acid at the end of the process when the cream is cool.
The pH of the cream should be slightly acidic