Preservation and Stability for Serum/Gel and Oil Scrub Formulations

Based on the staff's reply:

1. For the formula containing water, Alpha Arbutin, Glucosamine, Niacin, and Hyaluronic Acid, you should add Phenoxyethanol preservative after the mixture has fully formed into a gel. After adding, stir or shake to combine.
2. For a salt scrub mixed with Jojoba oil (a pure oil mixture), adding Phenoxyethanol is not necessary. Pure oils do not spoil due to bacteria. Spoilage in oils occurs due to oxidation or exposure to sunlight, which causes rancidity. To prevent oxidation, you can add antioxidants like Vitamin E T50 and Rosemary Oleoresin Extract (ROE). Storing the product in an opaque container or away from light also helps prevent spoilage from sunlight.