Compatibility of Alpha Arbutin and Stabilized Vitamin C

Based on the information provided, adding Alpha Arbutin 2% directly into Stabilized Vitamin C is generally not recommended without proper pH adjustment.

Here's why:

• pH Compatibility: Alpha Arbutin is stable within a pH range of 3.5 to 6.5. Different types of Stabilized Vitamin C have different optimal pH ranges.
• Natural-C Glycol: This type has a low pH (~2.5-3.0), which is too acidic for Alpha Arbutin's stability. Direct mixing would likely cause Alpha Arbutin to degrade.
• AA2G: This type is stable at a higher pH (6.5-6.8). While it's possible to combine AA2G and Alpha Arbutin, it requires adjusting the final pH of the mixture to a range where both are stable (e.g., 6.5-6.6). Direct mixing without pH control is unlikely to be effective.

Regarding the concern about them "counteracting" or creating dangerous substances:

• The issue isn't counteraction in the sense of negating effects or creating toxins in acidic conditions. The main problem is pH stability. If the pH is unsuitable, one or both ingredients become unstable and lose effectiveness.
• Dangerous substances (like hydroquinone) can potentially form from Alpha Arbutin in highly alkaline conditions, not acidic ones.

In summary, while Alpha Arbutin and certain Vitamin C forms can be used together, it requires careful formulation and pH control, not just direct mixing, to ensure stability and efficacy.