Formulation Advice for Your Cream Formulas

Regarding your questions about modifying the two cream formulas:

Formula (a) Hybrid Sunscreen Cream

• Replacing Light Cream Maker with Glyceryl Stearate SE and Cetyl Alcohol: While it is possible to create a cream base using hot process emulsifiers like Glyceryl Stearate SE and thickeners like Cetyl Alcohol, it is more complex than using a pre-calculated cream maker like Light Cream Maker or Soft Cream Maker. Achieving a stable emulsion with Glyceryl Stearate SE and Cetyl Alcohol requires careful calculation of the HLB (Hydrophilic-Lipophilic Balance) value for your specific formula, especially considering the oil phase. Without proper HLB balance, the cream may separate over time. Soft Cream Maker is a hot-process emulsifier that is easier to use as it does not require HLB calculation for stable emulsification.
• Emulsifying Oil with Glyceryl Stearate SE and Cetyl Alcohol: Glyceryl Stearate SE and Cetyl Alcohol can contribute to emulsification and thickening in a hot process. Glyceryl Stearate SE is a self-emulsifying type, and Cetyl Alcohol acts as a thickener and stabilizer. However, whether this combination at 4% and 2% respectively can stably emulsify exactly 10% oil depends on the specific type of oil used and the overall formula composition. It is not a guaranteed ratio without testing and potentially adjusting based on HLB principles.
• Heat Tolerance of SPF Protect Ultra: SPF Protect Ultra (including SPF Protect Ultra II and SPF Protect Ultra III) is stable and can withstand heat up to 80°C for 30 minutes during the mixing process.

Formula (b) Ceramide Anti-Irritant Cream

• Using Hot Process with Heat-Sensitive Ingredients: Hot process emulsifiers like Glyceryl Stearate SE and Cetyl Alcohol require the oil and water phases to be heated and mixed together at high temperatures (typically around 70-80°C) to form a stable emulsion. Simply adding heat-sensitive ingredients like Ceramide Complex and Chamomile after the cream has cooled below 40°C or 35°C is generally not sufficient to create a stable cream base using hot-process emulsifiers. The emulsification needs to occur at the required high temperature. Using a cold-process emulsifier like Light Cream Maker or Easy Cream Maker, which do not require heat, would be more suitable for formulas containing heat-sensitive ingredients.

Adding Fragrance to Both Formulas

• You can add 0.5% fragrance to both formulas by reducing the amount of water. This amount of fragrance is generally acceptable and should not negatively affect the stability or efficacy of the other ingredients in the formulas.

Regarding your observation about Light Cream Maker feeling sticky, while Light Cream Maker is designed to provide a light texture, the overall skin feel of a cream is influenced by all ingredients in the formula, particularly the oil phase and other thickeners or film-formers. Soft Cream Maker is another hot-process option that provides a soft texture, although the skin feel might be similar to Light Cream Maker for some users.

If you prefer a less sticky feel and want to use a hot process, exploring different combinations of oils and emollients in your formula, or trying Soft Cream Maker, might help achieve the desired texture. If you need to incorporate heat-sensitive ingredients, a cold-process emulsifier would be more appropriate.