[This.Formulating.Life]

Monograph from IFSCC on stability testing which I think you will find useful: https://ifscc.org/wp-content/uploads/2018/05/2-Fundamentals-of-Stability-Testing.pdf

To answer your first question, in addition to viscosity and thermal stability, I would add pH testing (essential for skin/ingredient compatibility and formulation stability), centrifuge testing (quick look at stability, cannot be relied upon, not always accurate representation of real life conditions), microscopic analysis (not essential but helpful for looking at droplet size and distribution), microbial stability/preservative efficacy testing (essential, self explanatory), cycling testing, sensory evaluation (user experience), photostability (light exposure, stability, I’d say important but not essential), packaging compatibility (asses product/packaging compatibility), and rheological testing (flow behaviour).

There are other types of testing too but it depends on what you’re formulating, what your end goals are etc. I’d encourage you to read the monograph at a minimum, it is a basic overview of stability, easy to read (even novice formulators can understand). There are also multiple chapters on both subjects in various textbooks, if you want to learn they would be your best avenue.

As for your second question, to conduct a simple spreadability test, you do not need complex equipment. The glass plate method is easy to set up. You place a known quantity of lotion, typically around 0.5-1.0g, between two glass plates. Then apply a specific weight on the top plate (e.g.. 500g), leave for a set time (e.g. 1min). Then you remove the weight, measure the diameter or area of the lotion spread (larger area = better spreadability). This test is best when comparing different iterations (or even batch to batch) especially when adjusting emollients, thickeners or emulsifiers. You could also use a texture analyser, if available, to measure the force needed to spread the product. This gives you numerical data, which is useful for tracking formulation improvements. Even sensory panels can give insight. Have multiple people apply a fixed amount of lotion to the skin and rate it on ease of spread, greasiness and after-feel but this is subjective. Plate testing is easy, quick and cheap.

[This.Formulating.Life]

@Fekher …Do you mean you don’t understand my point about glyceryl laurate? You are creating a lamellar gel network when using something like a 165 blend, so anything that disrupts the orderly stacking of those liquid crystalline layers (as I said in my previous message, like short-chain esters such as glyceryl laurate or even certain polar solvents like phenoxyethanol) can weaken that structure, reduce the viscosity, and destabilise the emulsion.

LGNs rely on consistent chain length and polarity to pack tightly, so when you introduce ingredients that don’t integrate well with the C16 and C18 fatty chains the system loses some of its internal scaffolding (support). This is especially noticeable when no gelling agent is present to provide backup thickening or support. You don’t have a gelling agent to provide backup support, so you should introduce a gelling agent. You also shouldn’t need to use so much emulsifier for such a small oil phase, which I did try to get across in my last message, but obviously, not well.

I agree it’s formulation based, but I’ve found piroctone olamine typically increases viscosity when used around 0.3–0.4 % in surfactant systems, acting almost like a secondary thickener (this has been my experience with it, however I’ve not used it as a preservative) and obviously this is dependant on the chemical environment and surfactant composition, which in your case seems to reduce viscosity, which was why I suggested that perhaps you were disrupting of LGN.

Sabowax AE and Neowax 165, might have the same INCI name, but it doesn’t mean they act exactly the same, slight differences in their molecular structure (ie PEG chain length or glyceride ratios) affect crystalline structuring and thickening. Even small molecular variations can significantly alter performance, especially in LGN formation. It isn’t surprising that you have found they act slightly different, and is the reason we use trade names on formulae not just the INCI name.

“About the used level of emulsifier you have right however it is not just to stabilise oil but to reach a desired viscosity and texture .”

I’m really not sure what you mean here? I don’t believe I said that an emulsifier is used just to stabilise oil?? Can you point me to where I did, because that would be egregious on my account.
I’m wondering if you are referring to me saying something in response your question 3? About cetearyl alcohol? I think maybe you misread what I wrote or lost in translation?

Cetearyl Alcohol is a fatty alcohol, a waxy solid blend of cetyl and stearyl alcohols, it is oil‑soluble and does not have a hydrophilic head to reduce interfacial tension, so it is not a primary emulsifier or surfactant. It has a REQUIRED HLB so it goes into your oil total calculation. I believe it is misleading to refer to it as an emulsifier because unlike true emulsifiers, cetearyl alcohol doesn’t stabilise oil–water droplets at the molecular interface. Its stabilising effect comes from forming a lamellar network, increasing viscosity in the oil phase, which slows droplet movement and coalescence. therefore it improves stability, this is via physical structuring (like other fatty alcohols and fatty acid, it doesn’t use interface chemistry.

In your example containing 5% cetearyl alcohol, 10% oils, and 5%, the correct classification would be 5% primary emulsifier, 10% oils, and 5% co-emulsifier or structural agent. Because as I said in my previous message, cetearyl alcohol is not part of the emulsifier percentage. It contributes to the oil phase and supports emulsion stability, but it does not carry out emulsification at the interface.

I really believe that this distinction is important. Including cetearyl alcohol in the emulsifier percentage can lead to miscalculations, particularly when formulating for stability and sensory performance. High levels of cetearyl alcohol, such as 5%, in combination with standard emulsifiers like glyceryl stearate and PEG-100 stearate, often result in products that are waxy, draggy, or slightly soapy in feel. Substituting it with structuring agents like stearic acid further increases viscosity and drag due to their high melting points and crystalline structure. In my opinion these effects, while useful in formulation design, are distinct from emulsification and should be accounted for separately.

[This.Formulating.Life]

What Phil said, free from claims are being phased out worldwide. It’s taking a while but in general we cannot say something is “free from”.
Like most countries, here in Australia “Free from” claims must be substantiated and not misleading under the Australian Consumer Law (ACL). TGA intervenes if claims imply therapeutic benefits or risk, e.g. “free from chemicals” could imply other products are harmful.

NZ follows similar rules via the Fair Trading Act 1986 enforced by the Commerce Commission.

In Canada “Free from” claims are discouraged when they imply a hazard that does not exist (e.g., “preservative-free” on a product that doesn’t need preservatives). If used, claims must be truthful, not misleading, and supported by evidence. Oh and if the ingredient is on the hotlist you can’t say it’s free from them. so, ingredients already prohibited cannot be referenced in “free from” claims.

If you read the document/regulations that Phil linked in the previous comment, you will see that “Free from” claims may render a product misbranded if they misrepresent safety or composition. e.g., claiming “free from parabens” can be misleading if implying that parabens are unsafe, given FDA has not banned them.

The EU rules basically say claims must be truthful, honest, fair, and supported by evidence; “free from [ingredient]” is not allowed if the ingredient is already banned; they must not denigrate legally allowed ingredients (aka, sulphate free is a HUGE no-no) and they must be relevant to the product (e.g., “alcohol-free” on water-based products is irrelevant).

ASEAN countries follow similar rules to the EU and the UK, aka, must not mislead consumers, must be substantiated by data and negative claims (e.g., “free from harmful chemicals”) are discouraged as they imply legal products with such ingredients are unsafe.

Mexico accepts “free from” claims if truthful and not misleading, but there’s growing scrutiny. Brazil discourages “free from” claims that imply superiority or safety gaps with approved ingredients. Argentina and Chile align with similar standards, can’t imply that other permitted ingredients are unsafe, must not mislead consumers, etc..

Japan, Korea, China, and most other countries have similar rules, free from is generally discouraged worldwide.

[This.Formulating.Life]

Cetearyl alcohol is a popular fatty alcohol because it provides excellent stabilisation and viscosity enhancement, it’s also cheap. Stearic acid provides good viscosity but less smoothness because it tends to form a different type of gel structure and can sometimes feel slightly draggy or waxy.

Cetyl palmitate is an ester rather than a fatty alcohol or fatty acid, which explains the thinner consistency, esters typically provide minimal structural support to emulsions. They are classed as emollients and contribute to your total oil phase.

Regarding combinations, yep, synergistic effects can produce superior results. You can mix a few different acids and alcohols to form a more robust system. Cetearyl alcohol is an example of a synergistic blend of fatty alcohols (It’s a mixture of cetyl and stearyl alcohols).

If you want to make a stable emulsion using stearic acid as an emulsifier you would need to use TEA, NaOH, KOH etc to form a soap emulsifier. This is how older emulsions were made. I believe Lush use this type of system in a few of their creams and lotions, the issue with this type of emulsifier is the higher pH and very inelegant skin feel. But I also think every formulator should learn how to react fatty acids to form emulsifiers. Maybe then people would stop referring to stearic acid as a “strong anionic emulsifier.” On its own, it’s not an emulsifier.

Honestly the HLB system remains controversial among formulators. While it provides a useful starting point, it has some big limitations in my opinion. It doesn’t account for formula complexity and ingredient interactions. It doesn’t take into account that things like temperature, pH, and electrolyte concentration affect emulsifier performance. Most modern emulsifier systems often work through multiple mechanisms beyond traditional HLB theory. Use HLB as a guide and rely on more practical testing and observation

Cetearyl alcohol functions as both an emulsion stabiliser (or structuring agent) and a rheology modifier. In your example with 5% cetearyl alcohol it should not be calculated as part of your primary emulsifier system (the 5% emulsifier you mentioned). However it does contribute to stabilisation and helps the emulsifier at the oil/water interface. It is better classified as a co-emulsifier or structural component. It does contribute to the oil phase % in practice.
So (again, in your example, as seems too much emulsifier for 10% oil) the most accurate interpretation would be, 5% primary emulsifier, 10% oils, and 5% structural agent (or co-emulsifier).

If you used 5% cetearyl with 5% GS+ PEG100S (165 bland) the result would be quite waxy/draggy/soapy and quite viscous. If you used stearic acid it would be thicker again, more draggy, more waxy.

Your experience with GS + PEG100S and Sensicare C1060 compatibility issues is interesting. Do you have a polymer in your water phase (0.2% Xanthan gum would help stability,) ? While I have not used sensicare C1060 (Piroctone Olamine (and) Phenoxyethanol (and) Glyceryl Laurate) as a preservative system myself, I do know that phenoxyethanol can sometimes affect viscosity.

I do wonder if presence of glyceryl Iaurate, which is a shorter-chain fatty acid ester (C12), could disrupt the formation or integrity of the lamellar gel network because it’s primarily built by the longer-chain stearyl components (C18). I wonder this because i know that systems combining fatty alcohols or esters with different chain lengths can affect packing and phase behaviour. Maybe this could potentially lead to less stable or lower-viscosity structures? I’m guessing here as not used this preservative.

Do you know what is the ionic change of the preservative is? Olamine usually refers to an anime salf. Could this potentially interact with the polar components of the lamellar gel network? or other ingredients in your formulation (as we don’t know the formula or process)? Ionic interactions can destabilise emulsifier structures or polymers, which can result in a viscosity drop or formama instability.

Maybe there’s another culprit? I’m not sure, as it could be other things in your system, and without a full formula and full process, it’s hard to give an answer or direction to follow. Others might have a better answer. Have you tried using another preservative ? Does it still happen? Have you done knockout experiments to work out actually cause the viscosity drop? Have you use this preservative in other formulae?

[This.Formulating.Life]

Is this The Mane Choice Dangerous Luster And Shine Illuminator (hair) oil? This product?https://www.myhairandbeauty.co.uk/the-mane-choice/curl-boost-spray/dangerous-luster-and-shine-illuminator Or https://www.youtube.com/watch?v=4FUN3c3c7L8 ?

If it is, it doesn’t have EHG (ethylhexylglycerin) only phenoxyethanol. It is just a thickened oil. It’s also from the UK, so that retinyl palmitate is has in it, needs to be less than 0.05% retinol Equivalent (RE) as it’s not a facial skin care product, which limits leave-on and rinse-off to 0.3%.

It’s been thickened with fumed silica (something like Aerosil 200, I’d assume). Fumed silica stabilises formulations by thickening the oil (creates 3D hydrogen-bonded network that entraps oil) and suspending insoluble or particulate matter (like botanical extracts).

In reality It is just Glycine Soja (Soybean) Oil, Cocos Nucifera (Coconut) Oil, Silica, Prunus Armeniaca (Apricot) Kernel Oil, Persea Gratissima (Avocado) Oil, and Tocopheryl Acetate. The rest is marketing.

They only have small amounts of water based extracts, likely totalling 0.010 - I counted 6 extracts? likely added @ 0.001%. each. Thus making the water phase well under 1.0%.

[This.Formulating.Life]

Yep. DF Williams textbook 2nd Edition (1996). Specifically Chapter One: Raw Ingredients. by E. SPIESS Cream Bases Chapter 1.11 p.p 28-29

[This.Formulating.Life]

I live in a high humidity area, and taught workshops for kids, I prefer to use an emulsifier rather than a solubiliser as I have issues with the solubilised kind. Have had luck with just water, but much better and never fails (esp. important when doing workshops with kids) so I use an emulsifier.

The spinning effect of a bath bomb depends on how the gases (CO₂) from the citric acid and baking soda reaction escape, as well as how foam and surfactants interact. Yep, I’d wager your SLSa is likely contributing to the excess foam. While 2.6% SLSa is within reasonable limits, it could be overpowering when combined with other factors, such as the tightness of the press or the amount of binding agent used. I’d try reducing it and see if it improves.

And it could also be the amount of tapioca starch you are using. Your ratio between Na Bicarb and Citric seems okay, but your tapioca might be a bit high and will effect spin. I’d personally reduce it, it’s just filler and really isn’t a necessary add.

PS80 doesn’t directly dampen spread but too much can add viscosity to the bath water, so will slow the fizz or cause clumping. Although your input is low, so I personally don’t think this would be too much of an issue.

But I find you need some air in them to spin, some people put pins etc to add airholes, I don’t both but I don’t pack tightly. The more densely it is packed the more likely it will trap air and not spin, when packing play around with how much you compress, if you are using a pneumonic press you are more likely to be packing tightly, but you can alter this. Just play around with it, and work out what works best for you.

You could add some PEG40-HCO but you would want to reduce your PS80 I would think, mix your PEG40 with your PS80 and water mix to homogenous before adding to dry phase.

[This.Formulating.Life]

the smell was there before the oxprotect, yes? I’ve not had a smell from oXprotect (I have all of that range from MSR). I would try formulating without zinc ricinoleate to see if the smell dissipates. Maybe also consider switching from Germall Plus to a non-formaldehyde-releasing preservative.

the amount of oxprotect you are using seems high? the use rate is 0.1-1.0 isn’t it?

[This.Formulating.Life]

because it acts as both an emollient and a solvent. so it helps the deodorant go on smoothly and feel soft, balancing out the drying effect of the aluminium. Plus, it gives a lightweight, non-greasy feel, which reduces irritation and makes the deodorant comfortable to wear, especially for sensitive skin. basically, it makes the deodorant work better and feel better, What’s your issue with it? Oh, it might help a bit with stability too?

[This.Formulating.Life]

Without formula and process, it’s hard to know what has happened, but in general benzoyl peroxide (BPO) BPO is not very soluble in water. When you dissolve it in ethyl alcohol, it may not be completely mixed into the water-based part of your face wash, potentially creating a suspension. This could cause it to look creamy or opaque (I think it’s bc the crystals would scatter light? that’s my understand but could be wrong).

But for viscosity loss, alcohol is a solvent and can always affect the performance of the surfactants in a system, so this could easily be the cause of the viscosity loss.

I would try using a solubiliser to help incorporate the BPO, like PEG-40 hydrogenated castor oil. I would also look at the concentration % of alcohol in the formula as it could be causing the viscosity loss. Is your rheology modifier compatible with alcohol? not all are.

As said, without formula and process, this is just guessing but might help you to work through what is happening.

[This.Formulating.Life]

I’m thinking that the phrase “doesn’t require both the presence of oil and water” in this context is a bit misleading. Glyceryl stearate S/E is a self-emulsifying version of glyceryl stearate, meaning that it can form an emulsion (blend oil and water) more easily because it contains additional emulsifying agents, like sodium and potassium stearate.

What it’s likely trying to say is that, unlike regular glyceryl stearate, which needs a separate emulsifier or both oil and water to create an emulsion, glyceryl stearate S/E has the ability to emulsify on its own due to the presence of those extra agents. However, it still needs oil and water to create an emulsion—it just doesn’t need extra emulsifiers to do the job. ??

[This.Formulating.Life]

For some reason my reply isn’t showing, but, yes, tromethamine usually comes as a powder, and yes, it’s normally hydrated before use. You just dissolve it in water to make pH adjustments easier. A 10% solution (10g Tromethamine in 90g water) is pretty standard, but you can adjust it depending on your needs. Water is best for dissolving Tromethamine—just make sure it’s RO/distilled to avoid any impurities affecting the pH.

[This.Formulating.Life]

Tromethamine usually comes as a powder, and yes, it’s normally hydrated before use. You just dissolve it in water to make pH adjustments easier. A 10% solution (10g Tromethamine in 90g water) is pretty standard, but you can adjust it depending on your needs. Water is best for dissolving Tromethamine—just make sure it’s RO/distilled to avoid any impurities affecting the pH.

[This.Formulating.Life]

You will need a PIF, Evidence of GMP Certification (compliance with ISO 22716), A safety assessment, Free Sale Certificate (TGA), Evidence of stability testing. Labels must be in both Arabic and English.

In regards to your question about the percentages, you list the percentage of the raw material, not just the actives. This is standard for both Dubai and EU regulations. For example, a surfactant blend used at 10% in your formula should be listed as 10%, even if it’s only partially active. For blends include the percentage of the entire raw material in the formula. In the EU, you need the exact percentages for ingredients, but for trade secrets or proprietary blends, it’s often acceptable to provide percentage ranges (e.g., “1-5%”) as long as the regulatory authority accepts it. You might need to check if Dubai allows for similar practices.

Dubai follows the guidelines set by the Dubai Municipality and its regulatory body is the Consumer Products Safety Section (CPSS). They do have guidelines on their website.

• This reply was modified 9 months, 2 weeks ago by  This.Formulating.Life.

[This.Formulating.Life]

I think you are breaking the gel with the shear.

I believe that excessive shear can potentially degrade HA molecules, leading to reduced effectiveness or even instability in the formulation.

Try adding HMW HA to the cool-down phase after emulsification is complete and the mixture has cooled down to around 40–45 °C. This might help improve stability as it reduces the exposure of HMW HA to high temperatures and shear forces during the emulsification process. Or only use low shear once you’ve added the HA like you’d do with carbomer.

[This.Formulating.Life]

Atomic Pom? I would say they might be able to help, they are in Canada. Can’t hurt to send a message and ask. https://www.atomicpomlabs.com/

atomicpomlabs.com

Canadian Cosmetic Lab for Entrepreneurs

A full service cosmetic lab dedicated to small brands making a big impact. We offer expert and innovative formulations, customizable private label products as well as small batch production. Expand, start or complete your skincare line with us.

[This.Formulating.Life]

You didn’t formulate the IPCS formula @Rhys you altered a formula and any changes made, especially ones where you are changing the main materials you will change the outcome. it even says of the formulation sheet that testing should be done. You should not really have been testing on inner forearm before even thinking about putting it under your arms.

 

But you cannot say you made an IPCS formula when you didn’t. You altered an IPCS formula and had a fail.
IPCS formula:

 

[This.Formulating.Life]

According to this: https://www.linkedin.com/pulse/shea-butter-market-size-statistics-comprehensive-outlook-sxfef/
The shea butter market is experiencing growth driven by several key factors: a rising demand for natural and organic skincare products, with shea butter’s natural benefits drawing health-conscious consumers; its expanding use across various cosmetic products; increased consumer awareness and market accessibility; the positive socio-economic impact on African communities involved in its production, appealing to ethically minded consumers; and technological advancements in extraction and processing that enhance its quality and appeal. These elements collectively contribute to the broader adoption and market success of shea butter.

linkedin.com

Shea Butter Market Size And Statistics: A Comprehensive Outlook And Forecast For 2032

Our recent report predicts that the Shea Butter Market size is expected to be worth around USD 4.5 Bn by 2032 from USD 2.

[This.Formulating.Life]

Not sure where you are @RKB but “free from” claims have some strict guidelines in the EU and there’s hope that this will turn into law rather than just guidance and push to stop companies using “free from” claims especially if all ingredients are used within regulatory limits (and thus seen as safe). In the EU if there are allergens in the fragrance used (components of fragrance), they may need to be listed on labels as well. (ref: https://food.ec.europa.eu/system/files/2018-07/codex_ccfl_cl-2018-24_ann-02.pdf )

A couple of articles:
https://www.cosmeticsdesign-europe.com/Article/2019/09/06/Cosmetics-free-from-claims-guidance-EU-explained
https://www.cosmeticsdesign-europe.com/Article/2019/09/09/Free-from-claims-cosmetics-EU-requires-honesty-fairness-and-safety-says-expert

https://bespokelaw.com/wp-content/uploads/2019/07/Bespoke-Free-from-and-hypoallergenic-claims.pdf

[This.Formulating.Life]

are you experiencing soapness? P20 is less “heavy duty” so to speak, ( better for solubilising small amounts fragrance etc), so maybe it is percieved as less soapy?

I don’t use liquid emulsifiers I use ones I need to heat first, I tend to use a blend that is cheap like like glyceryl stearate and peg 100 stearate.

[This.Formulating.Life]

I feel @Perry44 answered these questions for you with much better brevity than I have.

The first question “why does it have lower viscosity when you stick to same method” is pretty common (well I thought it was?) when scaling up? Because with industrial scale small inconsistencies are much harder to control. Industrial tanks may not provide the same level of shear as lab equipment, which will lead to uneven blending of ingredients. Temperature control can also be trickier and slight variations across the batch can affect things like fatty acids and fatty alcohols, and they can crystallise. Even raw materials, which seem identical, can have minor differences in composition that don’t cause issues in the lab but become more noticeable in bigger batches. Cooling speed would also affect the way a structure forms.

“the second question why the batches have lower viscosity become fine in industrial scale by reheating to 50 C degree and even lower with mixing?”
I’m going to assume this fixes the viscosity because it essentially allows the emulsion to reset. Like would re-melting the crystallised components, like fatty acids/alcohols helps them reorganise into a more stable structure, which boosts thickness. Maybe it’s also like breaking up clumps or poorly blended areas and helping dispersion or it could be reforming droplets or adjusting the drop size, too, right? So maybe that is increasing viscosity and stability.

So with some brevity (something I suck at), it’s most likely due to inconsistencies in mixing, cooling, or raw material quality, and reheating effectively gives the emulsion a second chance to form correctly.

[This.Formulating.Life]

Cosroma and DKSH both sell ascorbyl glucoside. I would contact your local supplier of these two companies. Ashland also have some AG in their perfectyl™ biofunctional (supplier blurb reads: perfectyl™ biofunctional is a high-tech chamomile extract, inspired by new aesthetic techniques, to clarify & smoothen skin flaws (such as pores & hyperpigmentation) for all ethnicities. Ashland uses fresh & living chamomile, Zeta Fraction™ technology and A.I to reveal the science of clear skin with a pure, patented extract naturally rich in GABA & flower acids.)

I’m with Mark on this though, I believe it’s better than SAP. I did struggle to find a supplier in Australia though. But, in general, I think ascorbyl glucoside coverts to AA quicker than SAP. It’s also more gentle (anecdotal). I also think it’s better for brightening formulations over SAP.

• This reply was modified 8 months, 2 weeks ago by  This.Formulating.Life.

[This.Formulating.Life]

@andy982183 So, so using your SLES example, you are correct, 28% becomes 0.28.

But you would then multiply it by the concentration/input% of surfactant you’re using. For instance, if your formula uses 10 % of SLeS, the calculation would be:

???????????? = 10 × 0.28 = 2.8

You then add all of them up together. I will base on known averages, but you would need to refer to datasheets in general as it changes from supplier to supplier. But using some averages so SLES (typically 30% or 70% active); AOS Liquid (typically 40% active); CDEA (Around 85% active); SLS Needle (Typically 95% active.)

SLES 9% × 0.28 = 2.52%
AOS 1.5% × 0.40 = 0.6%
CDEA 1% × 0.85 = 0.85%
SLS 0.5% × 0.95 = 0.475%

So then you have 2.52% + 0.6% + 0.85% + 0.475% = 4.445%

The total ASM is 4.445% and as @Aniela said that is around the ASM of facewash. I don’t formulate for homecare, so you would be best to refer to someone else about how much surfactant to use. But if the average shampoo is between 10% and 15% ASM, I would wager it’s a lot higher.

• This reply was modified 8 months, 2 weeks ago by  This.Formulating.Life. Reason: formatting, didn't want to add bold

[This.Formulating.Life]

But you have both listed in your formula? What was the emulsifying wax you used? An INCI name would help, but a trade name would be better. As @ketchito said, make sure your emulsifier works well with the amount of oil you’re using (especially the paraffin oil). If you’ve got a lot of oil in there (like 10% paraffin oil), you might need extra stabilisers &/or thickeners to keep things thick after it cools. As @ngarayeva001 suggested, GS+GSPEG100 would work if you kept the formulation unchanged. Like her, I’ve used mineral oil with GS+GSPEG100 lots of times over the years without issue.

The observed viscosity drop at around 40°C might be related to phase separation or incomplete emulsification, particularly if the emulsion hasn’t been given enough time to stabilise during cooling. I’m basing this on [quote] u(75°C) > u(70°C) > u(49°C) > u(53°C) > u(60°C) [/quote] as I think this suggests that the conditioner’s viscosity is sensitive to temperature.

Another thing is phase inversion could indeed be the reason your cream is losing viscosity. Gradual cooling and reducing mixing speed at lower temperatures can help prevent this, along with adjusting the emulsifier ratio to better handle the oil phase. So, make sure the oil and water are properly mixed at 70°C and let the emulsion cool down gradually so you don’t end up with crystals forming or the structure breaking down. Keep stirring gently as it cools. It’s fine to keep mixing at 600 rpm when it’s hot, but once it starts thickening (around 50°C), drop the speed to about 300-400 rpm.

[This.Formulating.Life]

“According to Custom Market Insights (CMI), the Global Shea Butter Market was estimated at USD 2.5 billion in 2021 and is expected to reach USD 2.8 billion in 2022 and is anticipated to reach around USD 5.2 billion by 2030, growing at a CAGR of roughly 8% between 2022 and 2030.” https://www.custommarketinsights.com/report/shea-butter-market