Formulation with DPHP and Perfect-C in Oil

Here are the answers to your questions regarding the use of Dipalmitoyl Hydroxyproline (DPHP) and Perfect-C (Ascorbyl Tetraisopalmitate) in an oil-based formula:

1. Can DPHP (2%) and Perfect-C (5%) be used together in an oil formula?
   Yes, Dipalmitoyl Hydroxyproline (DPHP) at 2% and Perfect-C (Ascorbyl Tetraisopalmitate) at 5% can be combined in an oil-based formula. Both ingredients are oil-soluble, and their proposed percentages are within the recommended usage rates. Note that DPHP requires heating to 80-85°C to dissolve in the oil phase. Perfect-C can also tolerate short-term heating, so they can be incorporated together in the heated oil phase.

2. If using these two in an oil formula, is Vitamin E needed? If so, what percentage for effectiveness and non-stickiness?
   While Perfect-C has antioxidant properties, adding Vitamin E is beneficial in an oil formula to help protect the oils and other ingredients from oxidation, improving the formula's stability and shelf life. For Vitamin E (Tocopheryl Acetate), a concentration between 0.1% and 0.5% is effective for both anti-oxidation of the formula and potential skin benefits without causing excessive stickiness. Using more than 0.5% Tocopheryl Acetate may result in a sticky feel. Vitamin E (dl-alpha tocopherol) is another option with higher bioavailability, typically used at 0.1-2%, but stickiness should be evaluated at higher percentages.

3. If combined in an oil formula, what should the pH be?
   pH is a measure applicable to water-based solutions. A pure oil formula (anhydrous) does not have a measurable pH. Therefore, the concept of pH does not apply to your oil formula.