Proposed Formulas for Very Dry Skin

Thank you for sharing your proposed formulas! It's great that you are exploring making your own skincare products using ingredients like L-ascorbic acid, shea butter, soy lecithin, ethoxydiglycol, glycerin, sodium lactate, sodium PCA, lactic acid (AHA), and panthenol (Vitamin B5). These ingredients, especially shea butter, glycerin, sodium lactate, and sodium PCA, are excellent for very dry skin.

Based on your proposed formulas and the properties of the ingredients, here are some considerations and suggestions:

Formula 1: Vitamin C (L-Ascorbic Acid) + Shea Butter

• Ingredients: Shea Butter, Soy Lecithin (Oil Phase) + L-Ascorbic Acid, Ethoxydiglycol, Glycerin (Water Phase)
• Feasibility: Combining water-soluble L-Ascorbic Acid (which requires a low pH of around 3.5-4.0 for efficacy and stability) with oil-based Shea Butter using Soy Lecithin as a Water-in-Oil (W/O) emulsifier is challenging to create a stable cream emulsion.
  • L-Ascorbic Acid is unstable in water, especially with heat, light, or air. While you plan to mix daily, the heat required to melt Shea Butter and dissolve Soy Lecithin (around 60-80°C) can degrade Vitamin C easily.
  • Soy Lecithin is a good W/O emulsifier, but creating a stable W/O emulsion with an acidic water phase (low pH) needed for L-Ascorbic Acid is very difficult and can easily lead to separation.
  • Ethoxydiglycol helps dissolve L-Ascorbic Acid and enhances skin penetration but doesn't solve the emulsion stability issue at low pH.
• Suggestion: If you want to use L-Ascorbic Acid with Shea Butter for very dry skin, consider making two separate phases and mixing a small amount just before application:
  • Water Phase: Dissolve L-Ascorbic Acid in a small amount of distilled water, add Ethoxydiglycol and Glycerin. Adjust the pH to 3.5-4.0 (you may need a pH adjuster like Sodium Hydroxide or Triethanolamine and pH strips).
  • Oil Phase: Melt Shea Butter (around 60-70°C) and let it cool. You can add a small amount of Soy Lecithin (although it's not ideal for acidic formulas, it might help with texture slightly).
  • When using, scoop a small amount of the oil phase and add a few drops of the water phase to mix on your palm before applying. This method helps preserve the stability of L-Ascorbic Acid better than trying to make a single cream emulsion.

Formula 2: AHA + Sodium Lactate + Sodium PCA + Shea Butter

• Ingredients: Shea Butter, Soy Lecithin (Oil Phase) + Sodium PCA, Sodium Lactate, AHA (Lactic Acid), Ethoxydiglycol, Glycerin (Water Phase)
• Feasibility: Similar to the Vitamin C formula, attempting a W/O emulsion with Soy Lecithin where the water phase contains Lactic Acid (AHA), which requires a low pH (not below 3.5 for consumers, and ideally not above 4.0 for efficacy), is also challenging to create a stable cream emulsion.
  • Sodium Lactate and Sodium PCA are excellent water-soluble humectants and components of the skin's Natural Moisturizing Factor (NMF), great for dry skin.
  • Lactic Acid (AHA) helps exfoliate and moisturize but requires a low pH for effectiveness.
  • Combining these ingredients in an acidic water phase and trying to emulsify with Soy Lecithin can easily lead to separation.
• Suggestion: To use these ingredients for very dry skin, consider making two separate phases or using a different emulsifier more suitable for low-pH O/W emulsions. If you want to use your current ingredients, the method of mixing two separate phases just before use (as described for the Vitamin C formula) is a more feasible DIY approach. Alternatively, you could try increasing the Soy Lecithin percentage and adding a thickener to the water phase (like Xanthan Gum) to help stabilize, but stability is still not guaranteed.

Vitamin B5 (Panthenol) Hair Serum with Distilled Water

• Feasibility: Yes, this is feasible. Panthenol (Vitamin B5) is water-soluble and beneficial for hair, helping to moisturize and strengthen it.
• Suggestion: You can dissolve Panthenol in distilled water. However, if you plan to store it for more than a few days, it is highly recommended to add a suitable preservative to prevent microbial growth. The typical usage rate for Panthenol in hair products is around 0.1-0.5%.

Additional Notes for Very Dry Skin

The ingredients you have, such as Shea Butter, Glycerin, Sodium Lactate, and Sodium PCA, are excellent for moisturizing very dry skin. They help improve hydration, strengthen the skin barrier, and reduce water loss.

L-Ascorbic Acid and Lactic Acid (AHA) are beneficial for improving skin tone (Vitamin C) and exfoliating dry, rough skin to reveal smoother skin (AHA). However, formulating these acidic ingredients into a stable cream emulsion can be more complex.

Since you mentioned you haven't studied the percentages in detail, it is recommended to research appropriate usage rates for each ingredient and basic emulsion making techniques. Starting with simpler formulations might help you gain experience.

Hope this information is helpful! Feel free to ask if you have more questions.