Formulation Advice and Ingredient Properties

Thank you for sharing your formulation journey and questions. It's great that you are experimenting to find what works best for your skin!

Natural Oil Heat Stability

Regarding your question about natural oils with high heat resistance, the staff's reply is correct. Natural oils generally degrade when exposed to high heat, such as 80°C, especially the beneficial components like vitamins and antioxidants within them. This is why methods like cold-pressing are preferred for extracting oils, as they avoid heat to preserve the oil's quality.

While some oils may be more stable than others, prolonged heating at 80°C will likely cause some level of degradation. If you need to incorporate oils into a heated phase, it's best to minimize the heating time.

Squalane Usage for Skin Feel

Squalane is an excellent choice for improving skin feel. As the staff mentioned, it is a very light oil that absorbs quickly and is non-greasy, making it suitable for reducing the sticky feeling you experienced with Vitamin E and Hyaluronic Acid. It can be used at high concentrations, even up to 100% as a standalone product.

For improving the skin feel in a cream formulation, the appropriate percentage will indeed depend on your overall formula. However, to achieve a noticeable improvement in lightness and absorption in a 100g cream, you could start by incorporating Squalane in the range of 5-15%. You can adjust this percentage based on your desired skin feel, increasing it for a lighter, faster-absorbing texture.

Emulsifiers: Soy Lecithin, Polysorbate 20, and Flora Solve Clear

Your observation about Soy Lecithin being difficult to dissolve in a low oil percentage (0.5% Bisabolol and 0.2% Vitamin E) is accurate. Soy Lecithin typically requires a higher oil phase percentage (often 3-10% or more, depending on the water content) and heating to properly emulsify water and oil.

Switching to Polysorbate 20 is a good thought if you want to avoid heat, as it is cold-processable. However, as pointed out by another user and the staff, Polysorbate 20 is primarily a solubilizer and a co-emulsifier. It can only solubilize a small amount of oil (typically 1-2%). For an oil phase of 5% (Squalane + Vitamin E + Bisabolol), Polysorbate 20 alone would likely not be sufficient to create a stable emulsion or a clear solution; it would likely result in a cloudy or separated mixture.

If your goal is to create a clear solution rather than a cream emulsion, Flora Solve Clear is a much more suitable option for solubilizing 5% oil in a water-based formula. The staff recommended using Flora Solve Clear at about 2-5 times the amount of your oil phase. For your 5% oil phase, this would mean using 10-25% Flora Solve Clear. You can start with 10% (2 times the oil) and increase if needed to achieve clarity.

Mixing Method with Flora Solve Clear: To use Flora Solve Clear, first mix it thoroughly with your oil phase (Squalane, Vitamin E, Bisabolol). Then, gradually add this oil/solubilizer mixture to your water phase while stirring until clear.

Understanding HLB and Emulsion Types

• HLB (Hydrophilic-Lipophilic Balance) is a value indicating how water-soluble or oil-soluble an emulsifier or surfactant is. A higher HLB value (typically above 10) means the substance is more water-soluble and is generally used for Oil-in-Water (O/W) emulsions (oil dispersed in water). A lower HLB value (typically below 10) means the substance is more oil-soluble and is generally used for Water-in-Oil (W/O) emulsions (water dispersed in oil).
• Oil-in-Water (O/W) emulsion is where oil droplets are dispersed throughout a continuous water phase. These emulsions are typically lighter and less greasy, like most lotions and creams.
• Water-in-Oil (W/O) emulsion is where water droplets are dispersed throughout a continuous oil phase. These emulsions are typically richer, greasier, and provide more barrier protection, like some thick creams or ointments.

Your understanding that Oil-in-Water means the water phase is larger than the oil phase, and Water-in-Oil means the oil phase is larger than the water phase, is generally correct in terms of the continuous phase, though the total percentage of each phase can vary widely in both types.

Your Formulation Experiments

It's great to hear about your experiences with different formulations, including the Vitamin C E Ferulic formula (experiencing stickiness from Vitamin E and Hyaluronic Acid), the Glutathione formula (finding it drying with low Hyaluronic Acid but good for oxidation prevention), and the Alpha Arbutin whitening cream (seeing positive results). Your journey highlights how different ingredients impact skin feel and efficacy, and adjusting formulations based on personal preference and skin needs is key.

Keep experimenting! Finding the right balance of ingredients and techniques will help you achieve the perfect cream for your skin and lifestyle.