Mixing Water-Based Gels with Different Gelling Agents and Preservatives
Asked by: nichasrisawan
On: August 26, 2018
Product Type:
Cosmetics
Question
I have two water-based gel formulations that use different gelling agents. The second formulation contains the preservative DMDM Hydantoin. I would like to mix these two formulations together.
- Is it possible to mix water-based gels that use different gelling agents?
- If they can be mixed, how can I ensure the resulting mixture is stable and properly preserved? Do I need to add more preservative (DMDM Hydantoin or another type) after mixing to account for the dilution?
Answer
Based on the staff's response, mixing water-based gels that use different gelling agents is generally possible, similar to mixing water with water.
To determine if your specific formulations can be mixed and if the mixture will be stable:
- Test a small amount: Mix a small quantity of both gel bases together. Observe if they combine smoothly or if they separate immediately. If they separate, they are likely incompatible.
- Check preservative concentration: If they mix well, calculate the final concentration of the preservative (DMDM Hydantoin in your second formula) in the combined mixture. Ensure this concentration is sufficient to prevent microbial growth based on the manufacturer's recommended usage rate for DMDM Hydantoin.
If the bases mix without separation and the final preservative concentration is adequate, the resulting mixture should be stable and less likely to spoil.