We use a stable form of Vitamin C (Sodium Ascorbyl Phosphate) and Vitamin A (Retinyl Palmitate).
SAP is generally less susceptible to oxidation. It is more stable than other forms of Vitamin C, such as L-ascorbic acid.
And the degradation rate of Retinyl Palmitate is generally slower than other retinoids, such as Retinol or Retinoic Acid.
While exposure to sunlight and air can potentially degrade SAP and Retinyl Palmitate over time, proper packaging and storage can minimize degradation.
Refilling the product usually only takes a couple of minutes and it doesn't happen everyday, the degradation should not be a concern as long as following the instructions.
Products containing these ingredients should be packaged in opaque containers to protect them from light exposure. It's recommended to store them in cool, dry places away from direct sunlight.