Necessity and Function of Excipients in Homemade Cosmetic Formulations
Question
I understand that commercial cosmetics use excipients (สารปรุงแต่ง) primarily for market appeal, extended shelf life, and aesthetics. If I am mixing cosmetics for personal use, are these excipients unnecessary?
I read in another thread that simply mixing water-soluble actives like B3 or B5 with water and applying it to the face can yield good results. Does this mean:
- Any water-soluble active can be mixed with water and applied directly for good results without needing texture modifiers?
- Any oil-soluble active can be mixed with oil and applied directly for good results without needing texture modifiers?
- Or are delivery systems (สารประเภทนำพา) still necessary for certain active ingredients that cannot penetrate the skin well with just water or oil?
Answer
Hello,
Thank you for your question and sharing your understanding. It's true that commercial cosmetics use excipients (สารปรุงแต่ง) for aesthetics, shelf life, and market appeal. However, excipients serve several other crucial functions that are also beneficial even when mixing ingredients for personal use.
Regarding your points:
- Mixing water-soluble actives (like B3 or B5) with water: This can work to some extent, and the skin will receive the active ingredient. However, a simple water mixture may not be stable (actives can degrade), can be prone to microbial contamination without preservatives, and might not optimize absorption into the skin. The texture might also feel less pleasant, which, as the staff mentioned, can affect how often you want to use it.
- Mixing oil-soluble actives with oil: Similar to water mixes, this can deliver the active. But stability, potential for oxidation (for some oils/actives), and skin feel are considerations. An oil-only product might feel heavy or greasy for some skin types.
- Need for delivery systems: You are correct. Some active ingredients have difficulty penetrating the skin barrier on their own due to their size, charge, or solubility. Delivery systems (like liposomes, emulsions, or specific polymers) are designed to help these actives reach their target layers in the skin more effectively, enhancing their performance.
In summary:
While you can mix some actives simply with water or oil for personal use, incorporating appropriate excipients offers significant advantages:
- Stability: Prevents ingredients from separating or degrading over time.
- Safety: Preservatives prevent bacterial/fungal growth, which is important for water-based products.
- Efficacy: Emulsifiers, penetration enhancers, and specific bases can improve how well the active ingredients are absorbed by the skin.
- Texture and Feel: Thickeners, emollients, and other texture modifiers make the product more pleasant to apply, encouraging consistent use.
- Compatibility: Excipients ensure ingredients mix well and remain stable together.
So, while not strictly necessary for every simple mix, using some basic formulation principles and appropriate excipients, even in homemade products, can lead to a more stable, safer, more effective, and more enjoyable product compared to just mixing an active with plain water or oil.
Hope this helps clarify things!