Choosing Preservatives for Sensitive Skin Gel Formula with Pro Polymer

Choosing Preservatives for Water-Based Gel Formulas for Sensitive Skin

Hello! I understand that finding a suitable preservative for sensitive skin that is also compatible with your formula requires careful consideration. Based on the issues you've encountered and the information provided, here is some additional advice:

Issues with Using Preservatives in Pro Polymer Gel

• Phenoxyethanol: You experienced burning sensation when using Phenoxyethanol, indicating that this ingredient may not be suitable for your sensitive skin.
• Eye Preserved™ (Polyaminopropyl Biguanide): The problem of white clumps forming when adding Eye Preserved™ in the final step of your Pro Polymer gel can occur. This is because Eye Preserved™ is a cationic ingredient (positively charged), while Pro Polymer is an anionic polymer gelling agent (negatively charged). When oppositely charged substances meet, they can cause precipitation or incompatibility, leading to the gel structure breaking down and forming clumps. As advised by the staff and C7, the initial solution is to continue mixing or blending the clumpy mixture until it becomes uniform. After that, you can gradually add a little more Pro Polymer while mixing to adjust the gel's consistency back to your desired level.

Using Mild Preserved™ (Ethylhexylglycerin) in Water-Based Formulas

Regarding pure Mild Preserved™ (Ethylhexylglycerin), it is not directly soluble in water. However, it dissolves well in glycols such as Propylene Glycol or Butylene Glycol. Therefore, if you want to use pure Ethylhexylglycerin in a water-based formula without other dispersing agents, you might need to dissolve it in a glycol first before incorporating it into the water phase.

However, in your case, since you are using Pro Polymer as a gelling agent, even though Ethylhexylglycerin is not water-soluble, the structure of the gel formed by Pro Polymer helps in dispersing the Ethylhexylglycerin. Thus, according to the staff's advice, adding Mild Preserved™ (Ethylhexylglycerin) in the final step after the gel has formed is a feasible method.

In addition to pure Ethylhexylglycerin, there are also Mild Preserved™ products that are Ethylhexylglycerin-based blends designed for easier use in water-based formulas, such as:

• Mild Preserved Eco™: This is a blend of Ethylhexylglycerin and 1,3 Propanediol, which helps allows it to dissolve directly in water by simply stirring or blending until clear. It is suitable for water and gel formulas and can even be claimed as Preservative-Free according to some FDA regulations.
• Mild Preserved SC10™: This is a blend of Ethylhexylglycerin and Caprylyl Glycol. It is also highly effective and gentle. It has lower water solubility than Mild Preserved Eco™ but disperses better in formulas containing surfactants or emulsifiers.

Other Alternative Preservatives for Sensitive Skin in Water-Based Formulas

Besides Eye Preserved™ and Mild Preserved™, there are other alternative preservatives that are suitable for water-based formulas and sensitive skin. These are generally gentle and water-soluble:

• Global Guard™ 221: This is a broad-spectrum preservative that is highly water-soluble and easy to use. It works well within a wide pH range (2-7) and is globally approved.
• NaturePreserve™ LB2: This is a natural origin preservative that is water-soluble. It is highly effective against bacteria and fungi at low pH values (2.0-6.5) and is suitable for skin and hair care products.

Summary:

For your water-based gel formula using Pro Polymer and sensitive skin:

1. Eye Preserved™: Although gentle, it has compatibility issues with Pro Polymer, causing clumping. If you choose to use it, follow the advice to mix/blend until uniform and then adjust consistency by adding more Pro Polymer.
2. Mild Preserved™ (Pure Ethylhexylglycerin): Can be used in the Pro Polymer gel by adding it at the end, or by pre-dissolving it in a glycol before mixing into the water phase.
3. Mild Preserved Eco™: This is a very good option as it is directly water-soluble, easy to use, and gentle.
4. Global Guard™ 221 and NaturePreserve™ LB2: These are excellent broad-spectrum preservative alternatives that are water-soluble and likely suitable for your sensitive skin.

I recommend considering Mild Preserved Eco™, Global Guard™ 221, or NaturePreserve™ LB2 as primary options to test. Regardless of which preservative you choose, it is always recommended to perform a Challenge Test to confirm its efficacy in protecting your specific formula before commercial production.