Aloe Vera Gel Formulation: Thickener, Preservative, and Texture Issues

Subject: Gel Formulation Advice

Thank you for your questions regarding your aloe vera gel formulation. Based on your requirements for a moisturizing and anti-aging gel with a pH of 5.5, low chemical content, and high natural ingredients, here is some guidance:

1. Aloe Vera Source: Using fresh aloe vera juice is not recommended due to high microbial contamination risk. Using a cosmetic-grade Aloe Vera Extract (10:1 FullAssay™) is the correct and safe approach. While you can use more than 3%, excessively high amounts (like 9%) might make the gel sticky without significant extra benefits. It's often better to use an appropriate concentration (e.g., 3%) and combine it with other active ingredients.

2. Gel Thickener: For ease of use, especially for beginners, Pro Polymer is recommended. It creates a nice gel texture and can also help incorporate small amounts of oil into the formula.

   • Regarding your test results: Hydroxyethyl Cellulose can sometimes leave a film, but pilling is not typical. Pro Polymer has a natural scent, but it should be mild at 1%; a strong bad smell might indicate an issue with the ingredient itself.

3. Active Ingredients: Your chosen ingredients - Hyaluronic Acid (Nano), Rose Hip Oil, and Asiatic acid (from Centella Asiatica extract) - are excellent choices for moisturizing and anti-aging.

   • Hyaluronic Acid and Asiatic acid are water-soluble and easily incorporated.
   • Rose Hip Oil is an oil and requires emulsification to mix into a gel. Pro Polymer can help with this. A recommended usage rate for Rose Hip Oil in a formula is around 5% for optimal benefits.

4. Essential Oil: Essential oils are oil-soluble and can be added for fragrance. They need to be emulsified into the gel base, which Pro Polymer can assist with. Adding essential oil helps mask the natural smells of other ingredients.

5. Preservative: Optiphen (Phenoxyethanol) is a suitable preservative. No single preservative is "best"; each has different properties. Optiphen is effective and widely used.

   • The strong smell you experienced with Optiphen in fresh aloe was likely due to the fresh aloe spoiling, as it cannot be effectively preserved this way. Optiphen itself has a smell, but it should not be overpowering at the typical usage rate (usually up to 1%).

6. Mixing Method (using Pro Polymer):

   • Combine all water-soluble ingredients (Aloe Vera Extract, Hyaluronic Acid, Asiatic acid, etc.) with the water phase.
   • Slowly add Pro Polymer while mixing until the gel forms and is smooth.
   • Add the oil-soluble ingredients (Rose Hip Oil, Essential Oil) and mix thoroughly until fully incorporated.
   • Finally, add the preservative (Optiphen) and mix well.
   • Check and adjust the pH to 5.5 using a pH meter.

By using cosmetic-grade ingredients and following the correct mixing procedure, you can create a stable and effective aloe vera gel.