Home Cosmetic Science Talk Formulating Skin Stable Hydroquinone Cream formulation.

  • belassi

    Member
    December 4, 2017 at 3:39 pm

    Not likely because it is a banned ingredient in most countries.

  • bill_toge

    Member
    December 4, 2017 at 11:39 pm

    in what way is it unstable?

  • oldperry

    Member
    December 5, 2017 at 12:14 am

    Just to add clarification, Hydroquinone is not banned in the US. It is a monograph ingredient however so you have to follow the FDA monograph guidelines.

    It’s also not technically banned in the EU. It’s just that it is a drug product that requires a prescription.

    As @Bill_Toge said, we’d need to know how your current product is unstable. 

    Here’s a starting formula
     

  • belassi

    Member
    December 5, 2017 at 4:00 am

    Sorry to assume it was a cosmetic.

  • Mamun

    Member
    December 5, 2017 at 4:27 am

    Bill_Toge , it discolors after 2-3 days. I need to preserve the formulation for at least 1 and 1/2 yrs.

  • belassi

    Member
    December 5, 2017 at 5:30 am

    What colour change did you notice?

  • bill_toge

    Member
    December 5, 2017 at 8:58 am

    @Mamun chances are the ascorbic acid is the culprit here; something like sodium erythorbate will do the same job with less discoloration

  • Mamun

    Member
    December 5, 2017 at 9:02 am

    Belassi it changes to reddish brown and ultimately black .

  • Mamun

    Member
    December 5, 2017 at 9:04 am

    Bill_Toge can u plz explain why ascorbic is responsible for discoloration? any other ingredient instead of sodium erythorbate?

  • em88

    Member
    December 5, 2017 at 11:23 am

    Ascorbic acid is not stable and it changes the color to yellow-orange, by transforming in L-Threonic and oxalic acid.

  • drbobverdient-biz

    Member
    December 5, 2017 at 4:35 pm

    @em88   i agree as i saw the problem before any posts but waited to be sure the instability was due to color change.

  • belassi

    Member
    December 5, 2017 at 5:53 pm

    You are using actual ascorbic acid rather than one of its more complex derivatives? If so, I don’t think you will ever get acceptable stability.

  • drbobverdient-biz

    Member
    December 5, 2017 at 6:47 pm

    I think MAP would be the best choice as ascorbyl glucoside/ etc will react with semiquinone radicals formed from hydroquinone.

  • Mamun

    Member
    December 6, 2017 at 9:08 am

    Dr. Bob… is it due to the effect of pH of the media on ascorbic acid? as far as I know in the pH range of 1.0–4.4, the decomposition rate of ascorbic acid increases, while at pH 5.4–7.2, it decreases. due to alkaline pH, hydroquinone rapidly oxidized,tht’s why I kept the pH of the emulsion at 5-5.5. 

  • drbobverdient-biz

    Member
    December 6, 2017 at 3:19 pm

    The ascorbic acid is unstable below 7 and discolors.Rate is likely Ph dependent.I would use MAP at the the current Ph of the system:should not discolor.____https://www.sciencedirect.com/science/article/pii/S0731708596019048

  • doreen

    Member
    December 12, 2017 at 3:35 am

    @Belassi
    I can understand why one would prefer ascorbic acid over stabilized forms:
    http://thebeautybrains.com/2014/05/which-kind-of-vitamin-c-is-best-for-skin-the-beauty-brains-show-episode-31/
    And it is stable in anhydrous systems (the brand CSI has 12% LAA + 98% butylene glycol).

  • amitvedakar

    Member
    February 15, 2018 at 7:47 am

    Try sodium  Metabisulphite It makes cream whiter.

  • teewaya

    Member
    February 18, 2020 at 3:40 pm

    I’m a year late, I see. 
    I work with HQ a lot. I include sodium sulfite at 0.1% and keep pH between 6.3 - 6.7. Never had a problem. 
    If you decide to stick to including Vit. C, you’re better off choosing one of it’s more stable forms such as MAP

  • Uchenna

    Member
    August 24, 2020 at 6:34 am

    teewaya said:

    I’m a year late, I see. 
    I work with HQ a lot. I include sodium sulfite at 0.1% and keep pH between 6.3 - 6.7. Never had a problem. 
    If you decide to stick to including Vit. C, you’re better off choosing one of it’s more stable forms such as MAP

    Can you please recommend me a stable formula

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