This blend utilizes a dual organic acid approach, where levulinic acid and p-anisic acid are delivered as sodium salts for optimal stability and solubility. These salts are regenerated into their active “free acid” forms when the formulation pH is adjusted below 5.5. Beyond preservation, p-anisic acid provides documented calming activity by modulating the arachidonic acid pathway.
Key Benefit: Achieves Criteria A efficacy across all five test organisms in surfactant-based systems when used as a standalone solution.
Performance & Antimicrobial Strategy
- Spectrum: Rated “very good” across Gram-positive bacteria, Gram-negative bacteria, yeast, and mould.
- Emulsion Synergy: In O/W emulsions, the blend achieved Criteria A for P. aeruginosa and E. coli, but required a co-active for C. albicans.
- The Booster Effect: Combining 3.0% dermosoft® 1388 eco with dermosoft® GMCY MB at pH 5.3 allowed all five organisms to reach Criteria A.
- Secondary Functions: Glycerol provides moisturization, while the blend offers a gentle masking scent that does not interfere with added fragrances.
Critical Formulation & Solubility Guidelines
Formulators must navigate the pKa of p-anisic acid (4.47) and its tendency to crystallize.
| Parameter | Specification / Recommendation |
| Final pH Target | register to find out |
| Aqueous Systems | pH must be above 7 before incorporation to avoid premature crystallization |
| Maximum Dosage | 2.5% in aqueous systems (plus a solvent or solubiliser) |
| Solubility Boosters | Ethanol, surfactants, or glycols |
| Risk Factor | Overdosage or pH shifts can cause irreversible crystallization |
Emulsions: Add to the water phase.
Rinse-off Products: Mix directly with surfactants.
Boosting (Aqueous): Combine with additional organic acids (e.g., dermosoft® 700B) or phenethyl alcohol.
