Home Cosmetic Science Talk Formulating How to use two emulsifiers, that both have low HLB numbers?

  • How to use two emulsifiers, that both have low HLB numbers?

    Posted by Transformize on September 4, 2023 at 10:35 am

    Here’s a quote, “You’ll get better stability with blends of high HLB and low HLB emulsifiers versus a single emulsifier.” I just had an HLB question. How can you use two emulsifiers if both HLB values are low? A store product is using glyceryl stearate (HBL 3.6), glycol stearate and stearamide AMP (HLB 5.5). So, to make it easy, I’ll just use soybean oil (HLB 7) at 15% and coconut oil (HLB 8) at 5%. Total oils equal 20%. Therefore, the required HLB of the oil phase = 7.25, but when calculating these two emulsifiers, even at 0% for glycol stearate, and 100% for glycol stearate IP (covers both glycol stearate and stearamide AMP) the highest number I can get is 5.5, not even close to 7.25.
    Thanks in advance for your help.

    Lotion ingredients label, I got this idea from:

    water

    glycerin

    stearic acid

    caprylic/capric triglyceride

    glycol stearate - emulsifier #1 (HLB 5.5)

    shea butter

    soybean oil

    coconut oil

    glyceryl stearate - emulsifier #2 (HLB 3.6)

    caprylyl glycol

    triethanolamine

    cetyl alcohol

    phenoxyethanol

    fragrance

    carbomer

    hydroxyethylcellulose

    cocoa seed butter

    stearamide AMP - emulsifier #1 (HLB 5.5)

    disodium edta

    chamomile extract

    Transformize replied 8 months, 1 week ago 5 Members · 11 Replies
  • 11 Replies
  • Transformize

    Member
    September 4, 2023 at 6:31 pm

    Asking chatGPT, it looks like glyceryl stearate SE is the only emulsifier.

    Glyceryl stearate SE and glycol stearate IP are two different chemical compounds that are commonly used in cosmetics and personal care products as emulsifiers, thickeners, and stabilizers. They serve similar functions but are distinct in their chemical composition and properties.

    1. Glyceryl Stearate SE:

      • Glyceryl stearate SE stands for Glyceryl Stearate Self-Emulsifying. It is an ester formed from glycerin and stearic acid, which are both naturally occurring substances.
      • Glyceryl stearate SE is often used in cosmetic formulations to help mix oil and water-based ingredients. It is known as a self-emulsifying emulsifier, meaning it can create stable emulsions (mixtures of oil and water) without the need for additional emulsifying agents.
      • This ingredient is commonly found in creams, lotions, and other skincare products where a smooth, stable texture is desired.
    2. Glycol Stearate IP:

      • Glycol stearate IP stands for Isopropyl Palmitate, and it is not the same as glyceryl stearate SE. It is an ester derived from isopropyl alcohol and palmitic acid.
      • Glycol stearate IP is primarily used in cosmetics and personal care products as a thickening agent, emollient, and moisturizer. It can help improve the texture and feel of skincare products.
      • Unlike glyceryl stearate SE, glycol stearate IP is not typically used as an emulsifier to mix oil and water phases but is instead used to add richness and thickness to the product.

    In summary, the key differences between glyceryl stearate SE and glycol stearate IP are:

    1. Chemical Composition: Glyceryl stearate SE is derived from glycerin and stearic acid, while glycol stearate IP is derived from isopropyl alcohol and palmitic acid.

    2. Function: Glyceryl stearate SE is primarily used as a self-emulsifying emulsifier, helping to combine oil and water phases in cosmetic formulations. Glycol stearate IP is mainly used as a thickening agent and emollient.

    3. Emulsification: Glyceryl stearate SE can create stable emulsions on its own, whereas glycol stearate IP is not typically used for this purpose.

    Both ingredients have their own unique roles in cosmetic formulations, and their selection depends on the specific properties and functions desired for a given product.

    • Perry44

      Administrator
      September 5, 2023 at 4:55 am

      While ChatGPT can be helpful it can also be incredibly misleading. I wouldn’t put much faith in anything factual that it tells you. It has been trained on things written on the Internet which have a wide range of factual accuracy.

      The problem with your question is that there is no simple answer. HLB is a helpful guide but the numbers make it seem more precise than it actually is. Just because a number is placed on a characteristic doesn’t mean it is accurate or predictive.

      Also, your simple classification of “emulsifier” and “oil phase” is not accurate. For example Cetyl Alcohol will have an impact on your emulsion particles. So will Stearic acid. Carbomer will also impact emulsion stability which is what you’re really interested in. This is not taken into account when using the HLB system.

      Bottom line…systems are complicated. HLB can help clear things up but only in the most simple systems. The one you posted is not simple & HLB will not be helpful.

  • gordof

    Member
    September 5, 2023 at 12:13 am

    hi there

    I would like to say that HLB is a nice tool to get some Surface basic information about how your emulsifier will act in your formulation but, and it’s a big one in my opinion, you can and should not only use it on a calculation that you made for your formulations.

    Cosmetic development is next to science although a lot of trial and error and even if HLB can help you with a selection of Emulsifiers to determine their role it will not give you the Perfect mathematical tool for the formulation of a Cosmetic Product. The HLB from oils in different combinations is very versatile and I would never go to that point to say coconut oil has XXX HLB and Soja XXX HLB and I use XXX % of each so the Mixtuer HLB is XXX and my Emulsifier needs to match that.

    It would be so nice if that would work but in my experience that is not the case. You have so many influence factors like Liquid Crystalin structures Polymer network within your formulation Dropplet Size and so on that have a similar influence on the stability appearance and Touch of your formulation as the Emulsifier system.

    General Advice. Use 2 Emulsifiers, one is bigger (molecular wise) and one is smaller It gives you a denser packt surface area of your droplets and increases the necessary energy to brack the droplets and therefore gives more Stability. it can Limit the size of the droplets but normally the stability would be increased. Don’t use high (from 8-18 Froms O/W emulsions) and low HLB (from 3-8Forms W/O emulsions) together they want to make different kinds of emulsions and maybe don’t like the presence of the other Emulsifiere very much at least in my experience. There is a Gray Area between the HLB values but a generalistic rule, if something like that exists in cosmetic formulation, would be to not mix this kind of emulsifiers

    best wishes Tobi

  • Transformize

    Member
    September 5, 2023 at 9:52 am

    I’d like to thank both of you for your responses.

    gordof, thanks for the detailed breakdown, and bringing to my attention not to mix these types of emulsifiers.

    perry44, you are correct, there’s a lot of incorrect information on the internet. Thank you for your guidance, and mentioning carbomer.

  • Transformize

    Member
    September 8, 2023 at 1:56 pm

    1- Would Glycol Stearate IP (Glycol stearate, stearamide AMP) be a sufficient emulsifier to make a liquid lotion?

    2- If so, would adding the Glyceryl Stearate SE keep it liquified, so I can adjust other ingredients to make it the pourable thickness that I want. I’ll be using refined shea butter, or shea nut oil, and cetyl alcohol.

    Since I tried the lotion (ingredients in first post) and liked the slickness, I was wanting to replace the lotionpro 165 (50% glyceryl stearate, 50% peg-100 stearate) and BTMS-50 (50% Behentrimonium Methosulfate, 45% Cetyl Alcohol, 5% Butylene Glycol).

    Since I got the information about the carbomer, it may fix my emulsion stability when re-formulating this. I’m currently having two problems. Problem 1- The emulsion doesn’t separate, but over time the thickness turns more like water. Problem 2- As the lotion gets used, the Guar Hydroxypropyltrimonium Chloride makes the lotion stick to the sides of the bottle. This just makes the appearance look gross.

    My current liquid cream lotion ingredients are:

    water

    glycerin

    C12-15 alkyl benzoate (will be changing to caprylic/capric triglyceride)

    sorbitol

    panthenol

    colloidal oats

    allantoin

    fragrance

    Euxyl PE 9010 (1%)

    Euxyl K 900 (1%)

    disodium EDTA (0.2%)

    guar hydroxypropyltrimonium chloride (0.15%)

    LotionPro 165 (glyceryl stearate, peg-100 stearate)

    BTMS-50 (behentrimonium methosulfate, cetyl alcohol, butylene glycol)

    menthol

  • Fekher

    Member
    September 8, 2023 at 3:29 pm

    why using two Preservative with total level 2% that seems soo fake.

    Then stearic acid with Triethanolamine give Triethanolamine stearate which is high hlb emulsifier.

    • Transformize

      Member
      September 8, 2023 at 3:52 pm

      I’ve attached a pic, why I’m using two preservatives at the 1%. Looking at Euxyl K 940, this gives the guidance to mix both Euxyl PE 9010 and Euxyl K 900, and at 1% each both phenoxyethanol and benzyl alcohol are under their maximum usage rates. I could drop both preservatives down to 0.75%. This would be closer numbers to Euxyl K 940.

    • Transformize

      Member
      September 8, 2023 at 4:01 pm

      I would like to remove the triethanolamine, as I won’t be using the stearic acid. For a pourable product, stearic acids adds too much thickness. The shea butter, or shea nut oil’s percent is going to have to be very low. When using the emulsifier, which thickens (BTMS-50), 1% of shea nut oil made the lotion thick and not pourable.

  • ggpetrov

    Member
    September 9, 2023 at 1:03 am

    Your formulation sounds like a nightmare! GS SE is weak when used alone, but it also gives a very pleasant emulsions. I use it a lot in my lotions, but always in combinations. For example GS SE + Ceteareth-25, or GS SE + Emulsan.

    • Transformize

      Member
      September 9, 2023 at 11:07 am

      “GS SE is weak when used alone, but it also gives a very pleasant emulsions.”
      Thanks for mentioning this.

  • Transformize

    Member
    September 11, 2023 at 1:59 pm

    Reading about the Ceteareth-25, it mentions that it stabilizes. Changing the formula to Ceteareth-25, and another emulsifier, as I’m liking the feeling of gel, would I be able to eliminate the carbomer?

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