Formulation Advice

Here is the information regarding your questions:

REGU®-AGE Availability and Alternatives

REGU®-AGE may not be available at the moment. For reducing dark circles under the eyes, you can consider using Safe-B3 (Vitamin B3, Niacinamide) together with Encapsulated Caffeine (Slim-Coffee). These ingredients can help stimulate blood circulation, which is beneficial for reducing dark circles caused by poor circulation. The recommended usage rate for Safe-B3 around the eyes is no more than 2.5%, and for Encapsulated Caffeine, it should not exceed 5% for the eye area. Please note that if your dark circles are due to allergies, these alternatives may not be effective as the cause is internal.

Burning Sensation from Phenoxyethanol SA

If you are experiencing a slight burning sensation, it might be related to the Phenoxyethanol SA (Optiphen Plus) in your formula, even if you haven't experienced issues before. You can try reducing the concentration of Phenoxyethanol SA or consider using a gentler alternative preservative such as Mild Preserved Eco at a concentration of 1%.

Polyvinylpyrrolidone K90 (PVP-K90) and Thickening Alternatives

It sounds like Polyvinylpyrrolidone K90 (PVP-K90) is not forming a proper film and is causing flaking and stickiness that is difficult to wash off. You can remove Polyvinylpyrrolidone K90 from your formula. To maintain the thickness of your serum-like formula, you can add a thickener. Alternatives suggested are Pro Polymer or Xanthan Gum. Pro Polymer is a gel maker that can create a viscous, pudding-like texture at higher concentrations and helps suspend particles without being overly sticky once dry. Xanthan Gum is another thickener that creates a clear gel texture and can increase viscosity as desired.

CoolTouch™ (Menthyl Lactate) for Sensitive Skin

While CoolTouch™ (Menthyl Lactate) provides a cooling sensation and is generally gentler than menthol, there is still a possibility that it could cause irritation for individuals with sensitive skin.

Rich Cream Maker Availability and Replacement

Rich Cream Maker is currently not available in retail size but can be purchased in kilogram size by contacting customer service. The retail size was discontinued because a new type of cream maker is being introduced that offers a better texture and can emulsify more oil than Rich Cream Maker. The name of this new cream maker is not available in the provided information.