Clear Hair Serum Base and Preservatives

You want to create a clear, non-sticky hair serum base and add multiple herbal extracts along with a preservative.

Hair Serum Base

The Repair Hair Serum (Compare to Mise En Scene) is a clear, colorless liquid base primarily composed of silicones and oils. It is designed to be used at a high percentage (97-100%) and is suitable for adding oil-soluble actives and fragrances.

Consideration for Herbal Extracts: Since herbal extracts are typically water-based, adding a significant amount of them to this oil/silicone base might affect its clarity or stability. If you are adding only small amounts of extracts, they might disperse, but for larger quantities or better stability, you might need a base designed to handle both oil and water phases (like an emulsion base) or use extracts that are pre-dispersed in an oil-compatible medium. If you proceed with this base, add extracts gradually and observe the clarity and stability.

Preservatives for Herbal Extracts

Adding water-based herbal extracts introduces the risk of microbial growth (bacteria, yeast, and mold). A broad-spectrum preservative is essential. Based on the search and descriptions, here are suitable options:

1. Mild Preserved™ COS (pH 2-8, Broad Spectrum, No-Odor): This is a highly recommended broad-spectrum, water-soluble liquid preservative. It is effective against bacteria, yeast, and mold and works in a wide pH range of 2-8. This wide pH compatibility makes it very versatile and suitable for formulations containing various herbal extracts, which can sometimes affect the final pH. It is also odorless.

2. Preserve-BSB™ (eq. Optiphen BSB-W): This is another effective water-soluble liquid preservative blend (Benzyl Alcohol, Sodium Benzoate, Potassium Sorbate, Aqua). It provides broad-spectrum activity against bacteria, mold, and yeast. However, it is most effective in a pH range of 2-5.5. If your final serum with extracts falls within this pH range, it is a good option.

3. NaturePreserve™ Ultra (Gluconolactone & Sodium Benzoate): This is a natural-based powder preservative blend. It is water-soluble and effective against bacteria, fungi, and yeast. Its effective pH range is 3-6. It is important not to use this preservative with Vitamin C (L-Ascorbic Acid). Being a powder, it needs to be fully dissolved in the water phase.

Recommendation: For ease of use and broad compatibility with varying herbal extract pH levels, Mild Preserved™ COS is likely the most straightforward choice. If your final serum pH is consistently below 5.5, Preserve-BSB™ is also a strong option.

Important Note: When adding herbal extracts and preservatives, it is crucial to perform a challenge test on your final formulation to ensure the preservative system is effective against microbial growth under real-world conditions.