Preservative Recommendations for Your Water-Based Essence

Okay, I understand you are formulating a water-based essence (น้ำตบ) containing Prebio-care, X-Glycerin, Skin-mimic™, 4D Hyaluronic Acid, Small Molecule Hyaluronic Acid, and PiteraEx™. Since your formula includes ingredients like a ferment extract (PiteraEx™) and a prebiotic (Prebio-care), which can be susceptible to microbial contamination, using an effective broad-spectrum preservative is essential to ensure product safety and stability.

You are looking for natural or mild preservative options. Based on the available information, here are a few suitable choices:

• Probio-Protect™: This is a probiotic-derived preservative (Lactobacillus Ferment) that is considered natural and allows for a "preservative-free" claim. It is water-soluble, broad-spectrum, and also offers moisturizing benefits. It is used at a recommended rate of 2.0% and should be added without excessive heat.
• Coco-Preserve™: Derived from coconut extract, this is another natural, water-soluble, broad-spectrum preservative effective against bacteria, yeast, and mold. It works well in a pH range of 4-8. The recommended usage rate is typically 1.0-1.5% for water-based formulas like yours. Avoid heat above 50°C.
• Global Guard™ 221: This is a natural, water-soluble, broad-spectrum preservative blend (Dehydroacetic Acid & Benzyl Alcohol & Water). It is effective in a pH range of 2-7 and used at a rate of 0.5-1.1%. Avoid heat above 45°C.
• Mild Preserved Eco™ and Mild Preserved SC10™: These are blends (Ethylhexylglycerin with Propanediol or Caprylyl Glycol) that are not classified as traditional preservatives by the FDA, allowing for a "preservative-free" claim. They are considered mild, highly effective, and offer some moisturizing properties. Mild Preserved Eco™ works in a pH range of 4-9, while Mild Preserved SC10™ works up to pH 12. Both are water-soluble/dispersible and can tolerate heat up to 80°C for a short time. Recommended usage is typically 1.0-1.5%.

When choosing, consider the final pH of your formulation and any potential scent contribution (Thyme Care™, for example, has a strong scent and wasn't included in the top recommendations for this reason). Always perform a challenge test on your final formula to confirm the chosen preservative is effective at the chosen concentration and pH.

Here are the recommended preservatives:

• Probio-Protect™
• Coco-Preserve™
• Global Guard™ 221
• Mild Preserved Eco™
• Mild Preserved SC10™