Issues with Colour Stability in Body Wash

SarahSarah Member
edited November 2013 in Formulating
Hi,

I am having some issues with maintaining colour stability in a range of body washes. They are currently SLS based with CAB, methylcellulose etc.

I have tried the addition of Benzophenone-4 but I am not really seeing much improvement. I suspect that the issue is that the colours are in the product at very low concentrations - to give the product a "natural" appearance. The customer will not agree to increase the colour intensity.

Apart from moving to tinted bottles does anyone have any advice for a newbie?

Cheers
Sarah

Comments

  • I fixed something like that with Tinogard TS from BASF. The problem was caused by the perfume.
  • you can use sodium meta sulfate to protect colour
  • DuncanDuncan Member, Professional Chemist
    Is the colour dropping off due to light exposure, or just disappearing in the dark as well. If the latter the Benzophenones won't really help
    UK based, Over 20 years in Toiletries, After a 5 year sabbatical doing cleaning products, back in the land of Personal Care
  • Thanks Ayla - I have contacted my supplier for a sample however the samples I make in the lab without fragrance still fade. 

    Duncan - the light accelerates the process but the colours still fade when stored in a carton. 


  • DuncanDuncan Member, Professional Chemist

    That's interesting. Fading in the dark can be down to a couple of things. Either an oxidation reaction going off in there, or a preservative system that isn't quite as biocidal as it should be.

    For oxidation reactions an antioxidant such as BHT (or Vitamin E Acetate if BHT is verboten) can help, as can some of the Tinogards.

    Has the formulation passed a challenge (PAT) test. I had a foam bath that had a lot of royal jelly in it. A spore rich natural material. That needed both kathon and another preservative in there to keep it's colour. Without the second preservative although the product would have a TVC <10, there was a residual microbial activity in there. Spores would activate, bugs would grow, and get killed quickly. They would however eat the colour out before they died.

    Another question: Are you using regular dyes such as (for instance Red 33, Blue 1 etc) or are you using natural food dyes such as say Copper chlorophyll. The latter are notoriously unstable, and will not have a good shelf life in product without precautions.

    An idea of the formulation you are trying would give us a better idea

    UK based, Over 20 years in Toiletries, After a 5 year sabbatical doing cleaning products, back in the land of Personal Care
  • Chemist77Chemist77 Member, PCF student
    I have seen microbial presence interfering with the pH which can lead to color fading as well. But as Duncan pointed out every aspect has to be checked even the stability of pigments as well.
  • I have one face wash formula where I feel this problem and I have checked all the preservative test and it's passing
    I have taken atrial with different anti oxidants finally I success where I add sodium meta bisulfite
  • Chemist77Chemist77 Member, PCF student
    Keep the dosage of Na Metasulfite in check as it is known to cause dermatitis on sensitive skin.
  • I inherited this formulation - it is very basic/cheap:

    Water 31%
    SLS  46%
    CAB 2.5%
    Glycerin 1%
    Fragrance 0.8%
    Sodium Choloride 4%
    Hydroxypropyl methylcellulose 0.4%
    Tetrasodium EDTA  0.2%
    Citric Acid 0.2%
    Potassium Sorbate 0.3%
    Sodium Benzoate 0.3%
    Benzophenone-4 0.15%
    CI colours 0.002%

    The pH range is 5.35-5.55 on the spec and retention sample records.

    I have not had the wash micro tested - I will send a sample off today - it had never occurred to me that micro could be an issue in this circumstance. 

    Ditto with the oxidation - I will make up a batch with Vit E acetate - the BHT is a no go as this is a "natural" product. What rate of addition would you recommend Duncan? 0.1%?  



  • DuncanDuncan Member, Professional Chemist

    0.1% should do it Vitamin E Acetate wise.

    pH: Sorbates and Benzoates tend to be more optimum at slightly lower pH's thsn thst spec. Might be worth tweaking it down to 4.5 - 5

    UK based, Over 20 years in Toiletries, After a 5 year sabbatical doing cleaning products, back in the land of Personal Care
  • Chemist77Chemist77 Member, PCF student
    Further to the formula structure I notice that you have almost reached 50% level with SLS. You can bring it down to 25-30% level, increase cellulose a little to maintain the viscosity. It might bring down the cost too. I have seen most formulations with SLES and I also work with it and I feel it is easier to handle and never creates an issue with the colors. Since I don't see a solubilizer in the formula I am guessing clarity ain't an issue with you.
  • You have to use Disodium EDTA instead off Tetrasodium EDTA for < 7 pH , it will work better.
  • charmercharmer Member
    edited July 2015
    l'EDTA tétrasodique 0,05 à 0,1% MAX
    Certaines couleurs sont stables par rapport à AUTRES
    BENZOPHERONE3 0,02 à 0,05%WITH SMALL  AMOUNT OF AQUA

  • Change the colours. I had a similar issue with shampoo colours. My beautiful purple (blue + pink) turned to turquoise on exposure to light. Another combination just slowly faded. 
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • This preservative combination will actually turn a clear system (no color) yellow over time.  I have seen this time and again. If you can, I would try a different preservative system.

    Also, I have seen where suppliers will "bleach" their SLS so that the material itself has less color.

    If this bleach is not removed, it can remove your colorants as well.

     

  • we used Cibafast H Liquid (BASF) for colour stability..
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