"When we season our meals with salt or perfume ourselves, we maintain a subtle balance between excess and deficiency. The same balance is also important for preservatives in cosmetics, which should only be added within the lowest possible limits".explains Clariant.
Amica, a robot from Clariant's German innovation laboratories, is a new tool for determining these limits. It tests preservatives quickly and efficiently.
In preservative chemistry, the boundary between too much and too little is called the Minimum Inhibitory Concentration (MIC). This is the lowest concentration at which a preservative inhibits the growth of germs such as bacteria and fungi.
Amica - for Automatized Minimum Inhibitory Concentration Assay (Automated Minimum Inhibitory Concentration assay) - also known as "ami" in Latin - offers an alternative to manual MIC testing. " We chose it because having this robot is really like having a helpful new friend around. A very fast friend, at that.says Petra Schaal, Head of Preservation at Clariant's Clariant Innovation Center (CIC) in Frankfurt am Main, Germany.
At CIC, the robot works non-stop. With one sliding arm, Amica mounts pipette tips, aspirates liquids and fills them into microplates. With the other, it transfers the plates to integrated incubators and reading tools.
"The Amica is essentially a state-of-the-art high-throughput system that enables us to test the efficacy of antimicrobial compounds very rapidly, explains Petra Schaal. Different concentrations of compounds are mixed with germs and growth medium. The samples are then incubated and regularly monitored for a certain number of days.
Amica measures a series of parameters to determine the rate of germ multiplication in plate wells. In each series, serial dilutions of 32 antimicrobials can be tested against 8 different organisms. The well containing the lowest level of an antimicrobial to inhibit growth defines the MIC of that compound.
Using Amica for "safer" security
The Clariant robot enables CMI tests to be carried out much faster than with conventional methods. In a recent university study, a similar device also achieved an accuracy of 100 %. This is a difficult level for even the most conscientious laboratory technician to achieve.
"We use Amica to accelerate our collaboration with Clariant's personal care customers, says Petra Schaal. Each formulation has its own preservation needs. And finding the right balance quickly can be crucial to being first to market with a new product."
To help cosmetics formulators, Clariant provides an online database that can be consulted using a preservative search tool. The products featured include one of Clariant's specialties: multifunctional boosters. These synergistic compounds reinforce the effects of traditional preservatives, which can considerably reduce their use.
"Boosters like our Velsan SC make cosmetics less dependent on conventional preservatives and their potential drawbacks, explains Petra Schaal. They offer safer safety, so to speak, while being largely bio-based and providing all sorts of other benefits. Amica is a great tool for testing the effectiveness of these innovations."
Robotic precision, human creativity
In Amica's incubators, a tiny drop of multifunctional booster can be used alongside an alcohol or organic acid to combat typical enemies such as Staphylococcus aureus and Candida albicans.
The result of this kinetic analysis is a series of graphs and figures. In the case of Velsan SC, they show that the booster can more than double the effects of alcohols and considerably extend those of organic acids. Combined with natural plant extracts, it can even obviate the need for traditional preservatives.
This doesn't mean that the lab assistants are idle. Preparing high-throughput cycles requires planning and care. And in the end, human experience, intuition and creativity are still needed to guide the robot's work and give it meaning.
"Amica is more of a synergistic stimulant, notes Petra Schaal. It helps us to work faster for our customers, but also to test new ideas more quickly, which boosts our capacity for innovation."
