Question 1

How do I choose the right preservative for my formulation?

Accepted Answer

Decide according to the pH of the formulation, the type of emulsion, the water content and the sensitivity of your target group. For standard emulsions and gels, broad-spectrum systems dosed at 0.5–1.1 % are suitable – Cosgard (effective at pH 2–7, ideally below 5.5) or Euxyl PE 9010, which is practically pH-independent; for natural products choose Euxyl K712 (pH up to 5.5), Iscaguard IAF (pH 4–6) or Spectrastat G2 Natural MB.

Question 2

How does pH affect the efficacy of a preservative?

Accepted Answer

Organic acids and their salts work at an acidic pH of 3.5–5.5; Cosgard is effective at pH 2–7 (ideally below 5.5) and Euxyl PE 9010 is practically pH-independent. After emulsifying, always measure the pH of the finished product and acidify it slightly if needed – outside its range a preservative may not reach full efficacy.

Question 3

Does every formulation need a challenge test?

Accepted Answer

Yes, it is recommended when launching a new product or when changing raw materials. The test verifies how the formulation resists microbial contamination and confirms the efficacy of the chosen preservative system in the actual recipe – this matters especially with natural preservatives, whose efficacy always has to be verified in the specific formulation.

Question 4

Can several preservatives be combined for a stronger effect?

Accepted Answer

Yes, a combination of organic acids, glycols and a chelating agent widens the spectrum of activity and makes it possible to lower the total dosage of active preservatives. Correctly set pH and the addition of a chelating agent (Dermofeel PA-3) increase stability further. Always verify compatibility and stability in a stress test, and do not forget production hygiene.

PRESERVATIVES

Spectrastat G2 Natural MB, 5 kg

Spectrastat G2 Natural MB, 50 g

Technical Sodium Benzoate, 25 kg