Arxada’s Portfolio: Tools for the Modern Formulator
Through our Barentz distribution partnership, we bring Arxada’s well-known preservative lines—Proxel®, Dantogard®, TroyGuard™—into your formulation toolkit.
- Proxel®: A flexible, broad-spectrum option (often based on BIT/isothiazolinone chemistries) optimized for compatibility and regulatory acceptance.
- Dantogard®: A long-standing, cost-effective preservative system used broadly in cleaning formulations. This includes products like
Dantogard®, which offers low free-formaldehyde (less than 0.09%) while maintaining efficacy across surfactant systems.
- TroyGuard™:Specifically aimed at Home Care and I&I products, offering performance in challenging matrices with robust support from the supplier.
Arxada also emphasizes sustainability in its preservation mission: safeguarding health while reducing waste and environmental impact.
Barentz complements this with local lab capabilities (challenge testing, compatibility screening) and regulatory guidance.
The Role of Challenge / Preservative Efficacy Testing (PET)
A preservative system must be validated under realistic stress. That’s where challenge testing, aka preservative efficacy testing (PET), becomes indispensable.
- Standards and methods:Widely used protocols include USP 51, ISO 11930, and PCPC (formerly CTFA) methods. These specify inoculation of known microbial strains (e.g. S. aureus, E. coli, P. aeruginosa, C. albicans, A. brasiliensis) and measurement of microbial reduction over time (commonly 28 days).1,2
- Typical acceptance criteria:For PCPC/CTFA-style tests, a 3-log (99.9 %) reduction for bacteria and 1-log (90 %) reduction for yeast/mold by Day 7 are common benchmarks, with no regrowth permissible during the test duration.3
- Test duration and points:Classical challenge tests span 28 days or more, with microbial enumeration at intervals (e.g. Day 2, 7, 14, 21, 28) to trace kill kinetics.4
- Accelerated or screening variations:Some newer PET methods aim to compress timelines or use alternative sampling; however, the core principle remains: proving resistance to microbial load under real-world exposure.3
In practice, formulators should run PET on both bulk formulation and finished packaged product, and re-challenge aging samples during stability to confirm long-term efficacy.
Strategy in Practice: Putting It All Together
Here’s a roadmap to move from concept to a validated preservation design:
- Risk assessment:Identify likely contamination pathways, usage patterns, and worst-case conditions (e.g. elevated temperature, surfactant extremes).
- Preservative screening and compatibility:Use small-scale trials to test candidate actives (Proxel®, Dantogard®, TroyGuard™) across your full surfactant + additive matrix to detect antagonism or deactivation.
- Microbial challenge testing (PET):Conduct PET (USP 51, ISO 11930, or PCPC) on the prototype and packaged product versions, sampling multiple time points and tracking log reduction curves.
- Stability and aging re-testRe-challenge at intervals (e.g. 3, 6, 12 months) to ensure the preservative system remains robust throughout shelf life.
- Iterate & refine:If microbial control fails, adjust preservative blend, pH, chelants, or packaging, then retest.
- Regulatory and sustainability alignment:Validate that your chosen preservatives comply with target markets (e.g. EPA, EU BPR, CleanGredients, Safer Choice) and sustainability goals. Arxada’s support in global registrations and portfolio sustainability assessments helps here.
Preservation is no longer an afterthought—it must be engineered from day one. With Barentz’s technical and lab infrastructure, and Arxada’s scientifically robust preservative systems, you can design formulations that are safe, stable, and future-proof across markets.
Contact your Barentz technical representative to explore how we can help you build preservative strategies tailored to your formulations. Let’s elevate microbial control from “additive” to engineered reliability.
