Okay here is the product by Korean brand Dr. Ceuracle.
It's a biphase product, but it looks like one of the phases is emulsified. But if it is emulsified, how is it possible that the water phase (brown liquid) is not mixing with the emulsified phase, given that emulsifiers are present?
Unless I'm totally misunderstanding and that phase is not emulsified, but it definitely looks emulsified and there are emulsifiers in the INCI.

I've never seen anything like this and I'm dying to understand.
Here is the ingredients list.
Camellia Sinensis Leaf Water, Camellia Sinensis Leaf Extract, Saccharomyces Ferment Filtrate, Triethylhexanoin, Hydrogenated Poly (C16-14 Olefin,) Water, 1-2 Hexanediol, Methylpropanediol, Centella Asiatica Extract, Ficus Carica Fruit Extract, Theobroma Cacao Seed Extract, Shisandra Chinensis Fruit Extract, Ulmus Davidinia Root Extract, Amaranthus Caudatus Seed Extract, Sodium Hyaluronate, Hydrogenated Lecithin, Trilaureth-4 Phosphate, Polyquaternium-51, Helianthus Annus Seed Oil Unsaponifiables, Butylene Glycol, Dextrin, Ceramide NP, Ethylhexylglycerin

Comments
But I am curious....directions say... Shake well before using.... Do you know what happens when you shake well....Does everything temporarily whiten/emulsify for a moment....like a salad dressing that has been shaken? Or do they stay separate? I am assuming.....they combine for a moment?
Seems like over time....the ratios change, unless one is a very savant shaker.
I guess anything can be a trend nowadays since biphase toners has been there for ages. Even now "foaming" toners are a thing
🤷
Not really bi-phasic like makeup remover - it takes time to separate back to 2 layers.
The ingredient that was left out is Marketinga Moneyeta.
leaf water as first ingredient and not stable emulsion. preservatives don't work correctly in my experience in unstable emulsions. How much is the shelf life of this product?
Yes, this is a two-phase system, they are generally made with separate oil phases and water phase without an emulsifier so the phases separate quickly after shaking. You simply fill the water phase and then layer the oil phase on top of it.
In this particular case, the oil phase does contain an emulsifier, but in a quantity sufficient enough to give the oil phase the white color and enough to form the "emulsion" when you shake the product, but not enough to hold the emulsion together to ensure that the phases separate fairly quickly so you still have the "eye candy" of two distinct layers when the product sits on the shelf.
I'm working on a couple of these at the moment ... the products are designed to form two distinctly separate layers for the visual effect and you shake immediately before use.
See website for details www.desertinbloomcosmeticslab.com
Yes, that is a good approach ... separately preserve each the water phase and the oil phase with preservatives with the appropriate solubility for each phase.
See website for details www.desertinbloomcosmeticslab.com
In your serum one phase is water and water soluble ingredients. What is in another phase?
Think you're approach preserves the oil/water interface more so than the preserving the oil phase per se.
Don't presume the product is biphasic by intent. They may not have been able to establish stable emlusion.
The oil phase is using plant oils, Coco Caprylate Caprate, Phenonip and antioxidant (Rosemary Oleoresin.) I haven't had any issues thus far of oil phase separation due to non-compatible polarity.
I haven't done any kind of microbial testing yet because I only made my "final test" versions a week ago, but in 3 weeks I'm going to test for contamination using my microbial testing kits.
I have done shaking cycles. Here are my observations.
My first attempt at making this serum did not contain a preservative in the oil phase. I was always planning on using an oil phase preservative, just hadn't decided which one yet, and I was just experimenting at this point. I did have Germall in the water phase.
Throughout cycles of shaking, the oil phase became less and less transparent. I think because of drops of water being trapped in the oil phase, I'm not 100% sure but it seemed to get worse every time I shook the bottle.
Here's the interesting part. Since adding Phenonip to the oil phase, I haven't had any loss of transparency through cycles of shaking.
Not only did Phenonip not impact transparency itself, it also seems to make my oil phase brighter. I'm using some colorful oils to have a colorful oil phase layered on top of a clear water phase for visual effect. So for example one of my serums uses Sea Buckthorn Berry Oil.
Before I added Phenonip to my serum, I tested a small amount of it in pure Apricot Kernel Oil. I swear that overnight, the color of the Apricot Kernel Oil became brighter, and I could verify that by looking at the preserved and unpreserved Apricot Kernel Oil side by side the next day.
Any thoughts on what might explain the slight change in color?
Thank you so much for your feedback!! 🙂
Sorry Abdullah, I don't know why I thought you had also asked Phil's question.
The oil phase is using plant oils, Coco Caprylate Caprate, Phenonip and antioxidant (Rosemary Oleoresin.) I haven't had any issues thus far of oil phase separation due to non-compatible polarity.
I haven't done any kind of microbial testing yet because I only made my "final test" versions a week ago, but in 3 weeks I'm going to test for contamination using my microbial testing kits.
I have done shaking cycles. Here are my observations.
My first attempt at making this serum did not contain a preservative in the oil phase. I was always planning on using an oil phase preservative, just hadn't decided which one yet, and I was just experimenting at this point. I did have Germall in the water phase.
Throughout cycles of shaking, the oil phase became less and less transparent. I think because of drops of water being trapped in the oil phase, I'm not 100% sure but it seemed to get worse every time I shook the bottle.
Here's the interesting part. Since adding Phenonip to the oil phase, I haven't had any loss of transparency through cycles of shaking.
Not only did Phenonip not impact transparency itself, it also seems to make my oil phase brighter. I'm using some colorful oils to have a colorful oil phase layered on top of a clear water phase for visual effect. So for example one of my serums uses Sea Buckthorn Berry Oil.
Before I added Phenonip to my serum, I tested a small amount of it in pure Apricot Kernel Oil. I swear that overnight, the color of the Apricot Kernel Oil became brighter, and I could verify that by looking at the preserved and unpreserved Apricot Kernel Oil side by side the next day.
Any thoughts on what might explain the slight change in color?
Thank you so much for your feedback!! 🙂
ETA: sorry about the messy responses.
I was inspired by this product, you can see the phase distribution is closer to 80/20.
I'm not using surfactants as it's a leave on product.
Thank you so much for the feedback!!
https://ohlolly.com/products/sioris-time-is-running-out-mist
What i want to know is that are you making bi phase Product in expense of the quality because it is a trend or it has any benefit too that stable emulsion doesn't have?
I have made several bi phase Products in my practices not by intention but because i wasn't able to stabilize the emulsions as @PhilGeis said. And in my experience the composition of ingredients will be different at the beginnings and ends of the bottle and you can feel it. At beginning what you are using will have more of the oil phase ingredients and at the end it will have more of water phase ingredients.
I know that the ratio can change over time, which is one of the reasons I went with 50/50 distribution. Even if uneven dispensing occurs, it will likely not move the distribution much further from 40/60 or 60/40, based on my tests.
Plus, the product is packaged in a dropper bottle, which means that even if the user doesn't shake the bottle at all, they will still end up with a relatively even distribution of oil and water. I have tested this using both of the different dropper bottle designs I have (one round, narrow, one rectangular, wider.)
Experientially, the dropper bottle is different from the pour/spray bottle like the ones I linked.
Using a bi-phase product is completely different from using an emulsion in terms of the user experience. And also, I'm guessing, different from using a separated emulsion. It's like a mixture between using a serum and a facial oil.
See website for details www.desertinbloomcosmeticslab.com
If the consumer can use the Product without any effort, need to shake several times in each application is a minus point.
No emulsifier mean your product will be water thin and runny. Who prefer a runny Product over some viscosity?
You will not be able to use a lot of good ingredient like butters, waxes, allantoin, petrolatum, etc.
You use %50 oil phase because you know the bad thing is going to happen. That also increase your cost. I use %10 oil phase, it works well and no worries.
You use %50 oil, that would not make a noticable difference if it change to %90 or %10. what about ingredients that are used at small amounts and make a difference? They will have negative effects like less efficacy or irritation if percentage increased or decreased. Ingredients like preservatives, AHA/BHA, retinol, perfume, etc.
For how much time have you used such Products and how many bottles that you are saying the ratio changes from 50/50 to 40/60? I have used my such (failed) Products for years and i know if you don't use emulsifier the oil and water separate in seconds not even minutes and at the ends of 100g bottle there always is only water phase left.
For your preservatives, can you tell how much do you use. I need to see how it will work. When i recalled my bi phase Products the preservation system didn't work for more than a month or two no matter what and for stable versions i have samples from 2 years ago that are fine. Same formula and same amount of same preservative.
Separated phase is better that than no emulsifier. At least they will remain mixed a few minutes after shaking.
Droppers will be worse because the amount inside the dropper will not mix with rest of it when you shake the bottle.
I bet if you make the Product one phase, it would be more effective with less cost and you would like it.
I've been through 2 30 mL bottles so far and the oil and water phase ratio did not change beyond 60/40.
The product is not thin and runny. I have high molecular weight Hyaluronic Acid in the water layer, and oils with higher viscosity in the oil layer.
I disagree with your statement about no one liking "runny" products. "Runny" products like toners and essences are absolutely essential in the Korean skincare user community, for example.
There are no actives in this product, and no fragrance. I do not formulate with essential oils or fragrance.
Biphase products are very well liked in the skincare communities that I belong to, so it's not like this is something unheard of or something I totally made up. One of the formulators that I follow just made one on her YouTube channel. Institute of Personal Care Science has several biphase product formulations, as well. So I disagree with your overall attitude that no one will like a biphase product. It seems plenty of people do.
As I said, I have extremely robust preservatives in both the oil layer and the water layer, and will be testing for contamination in a few weeks.
I have a hard time believing that biphase products are impossible to preserve as you claim, given that there are so many on the market. Biphase makeup removers have been around for several decades. As Mark said, using a preservative in each layer with appropriate solubility is a good approach. I'm using Liquid Germall Plus and Phenonip, which are both as close to bulletproof as preservatives get. Maybe you weren't using an effective preservative in your separated emulsion.
You said "change is the best thing we can do." Well, that's exactly what I'm doing. It's about experimentation and innovation. It's the creative part of skincare formulation which is the biggest reason I formulate skincare.
Wish you success.