Like many laboratories nowadays, personal care labs face increasing workloads, needing to test more samples with the same number of staff. Notoriously secretive because of the competiveness of the industry, these types of labs must also meet the challenges of strict industry regulations. All these factors make technology and equipment very important in personal care laboratories, ensuring that products such as shampoos and lotions are as attractive as possible to the customer while also being safe to use.
Robert McGregor, marketing manager at Brookfield Engineering, which manufactures viscometers, rheometers, texture analyzers, and powder flow measurement instruments used in many personal care labs, says the kinds of tests personal care labs are able to do are quite amazing.
For example, texture analyzers, which apply compression or tension to materials to test how well they stand up to being pulled or squeezed, have attachments that enable a variety of tests. One device can be used with a texture analyzer to comb hair in order to see how shampoos and similar products will behave in the hair.
“It’s very simply a fixture that pulls a comb through a piece of sample hair that has been treated with a shampoo or conditioner,” McGregor explains.
Another fixture allows labs to test the internal strength of lipstick when it’s extended from its container, while another measures the amount of force needed to squeeze a product out of a tube or to push the plunger on a container. Texture analyzers can also be used to test the uniformity of the powder in a compact and how much force it can withstand before it cracks.
“Once you see what happens, it opens your eyes up and makes you say, ‘Wow, I didn’t know they could test those kinds of things,’” he says of the different capabilities texture analyzers bring to personal care labs.
Another key part of labs that develop and test such products is the rheometer.
“Rheometers may be used to fully profile a personal care product before, during, and after its application stages,” explains Anton Paar USA applications engineer Maxine Quitaro. “Rotational and oscillatory tests may be performed on the materials to mimic rest and shear conditions from processing to packaging and end use of the product.”
She adds that rheometers can also be used to measure material properties, such as viscoelasticity, recovery after shear, change in viscosity, effects of additives, strength, tackiness, and stability. Accessories can also allow users “to precisely study temperature effects of the material as well as the material’s friction and wear properties on a system, such as skin or hair.”
Oscillatory tests could also be run by a rheometer to further investigate the internal structure of the product for formulation modification purposes, Quitaro explains. After those tests are run, “comparative tests can then be performed by the rheometer to isolate the optimal formulation for a personal care product,” she says.
Stirrers can also be found in many labs that develop personal care products and are used for applications such as oil and water emulsions, batch work, viscous product mixing, and multiphase processes, says Marta LaForest, sales and marketing manager for laboratory products at Caframo.
“Our stirrers are recognized for their durability and power to mix heavy, viscous product at the lab bench level,” she says.
The overhead stirrer manufacturer’s new Sweep blade, which was recently displayed at the New York Society of Cosmetic Chemists (NYSCC) meeting in New Jersey, has gotten great reviews in the cosmetics market, LaForest says.
“It is designed for viscous mixing and fits onto an anchor paddle and pulls product off the side walls of a four-liter vessel,” she says about the blade’s unique features.
To measure the flow behavior of liquids and semisolids, personal care labs turn to viscometers.
“The companies that produce shampoos, hair conditioners, mascaras, lotions of various kinds—they will typically measure those products in quality control for viscosity to make sure they will not only flow out of the tube correctly, but that they will apply correctly when used by the customer,” McGregor says of how viscometers are used in the lab.
These instruments ensure that such products squirt properly out of the bottle, hold their position in your hand, and can be easily rubbed into the skin.
“The viscosity measurement gives an indication of how easy or how difficult that transfer process will be,” he says.
Powder flow testers, on the other hand, allow labs or manufacturers to predict the ability of the powder to discharge from the bins they are stored in, McGregor adds. Normally, in the manufacturing process the powder needs to come through a hopper at the bottom of the bin. Flow testers let the user know exactly how powder will flow before that process begins.
Changes in personal care lab instrumentation have been both mechanical and electronic.
In terms of rheometers, those changes fall mostly on the mechanical side.
“Over the past few years, the advent of air bearing motors has led to very sensitive torque measurements in rheometers,” says Prajakta Kamerkar, PhD, a product specialist at Anton Paar. “We have also seen the movement toward rheology measurements coupled with optical or application-specific accessories to study the structure in samples.”
Dr. Kamerkar adds other changes include tool recognition systems, such as a Toolmaster device, true gap measurements, and increased accuracy of temperature control due to the temperature- controlled hood system. That system “covers not only the sample but the measuring system and the surrounding atmosphere as well, thereby reducing temperature gradients.”
For texture analyzers, viscometers, and powder testers, most of the changes have been electronic.
“What you see happening now is that smartphones are being built into these instruments, so the way that you interface with the instruments is just the same way that you interface with a handheld device like an iPhone,” Mc- Gregor explains.
Such devices now have touchscreens, users can run any number and type of test they want, and everything is in the memory of the instrument, he says. “Every piece of data that is measured during the test is recorded by the instrument.”
Users can now transmit that data to central databases or use memory sticks and flash drives to transfer data to other devices, he adds. “The way in which data is being generated, gathered, and analyzed has changed significantly, and that’s because of the ease with which you can do that with today’s technology.”
McGregor says lab technicians no longer need to watch over their instruments, because the devices do everything automatically. For example, in a viscosity test, the user may need to rotate a spindle in a fluid for two minutes and then take a data point. Before, users would have had to sit and watch until two minutes were up, but that’s not the case anymore.
“Technicians no longer have to babysit the instruments,” he says. “The instrument knows automatically and it records the data for the technician.”
New technology is also helping labs meet the tough regulations of the industry, particularly 21 CFR Part 11, which stipulates that access to instruments must be controlled to ensure that only those with the proper training are allowed to run certain tests on the equipment. Labs must also make sure the data that comes out of that test is saved, cannot be modified, and is routed to the correct location, where it’s maintained as a permanent record.
“Instruments now have the intelligence built into them to comply with that requirement,” McGregor says.
As far as service goes for viscometers, texture analyzers, and powder testers, McGregor says these instruments come with calibration tools so customers can run verification checks themselves, adding it’s up to the labs how often they want to run those checks.
“Some very busy labs might actually do a calibration at the beginning of every shift,” he says. “Labs that are part of somewhat smaller companies may feel the need to check their instrument only when something is wrong.”
He adds users normally send their instruments to Brookfield for service and recertification on an annual basis, but, again, it’s up to the labs how often they want to do that.
A Technical Note
According to McGregor, it’s important for lab managers who use viscometers to learn as much as they can about viscosity measurement and be aware that it is not just one number.
A viscometer has a spindle connected to the instrument that is immersed in the fluid being measured and rotates at a defined speed. The resistance to rotation is what is measured by the instrument.
“What you learn about most materials, like shampoos and conditioners, is that if you change the rotational speed, you get a different number than the one you got at the first speed,” he explains. “That’s just the nature of viscosity.”
Taking an additional one or two measurements at different speeds is important for that reason, as it gives lab managers a better control point for their products, he says, adding that technology built into today’s instruments does all that automatically.
He sees more lab managers moving to this technology in the future as they become more aware of this aspect of viscosity.
“I think that as education continues in the lab manager world, they will start to appreciate this reality about viscosity and you’ll see them migrate more rapidly to the instrumentation because it’s got the intelligence built into it to do these types of tests automatically.”
One of the major challenges for personal care labs is just staying on top of new technology and how it can enhance productivity. But with the increasing workloads of these labs, it can be tough to find the time to research new technology and implement it as quickly as possible, McGregor adds.
“The capabilities are moving faster than the labs themselves,” he explains. “There’s also got to be an investment to upgrade from older equipment that they use to new equipment.”
While one might expect personal care labs to constantly be adopting the newest technology to keep pace with their competitors, like many of today’s cash-strapped facilities, these labs actually tend to be very careful about new purchases.
“Labs are very cautious about upgrading because they don’t have unlimited budgets to do that,” McGregor says, adding Brookfield instruments have a long life, with many personal care lab customers using products that are 10-15 years old.
He says lab managers need to do their homework and look at as many vendors as possible to ensure they get the best bang for their buck.
“They need to compare the capabilities and features of the instrumentation and make sure that they match the ways in which they want to use the instruments in their lab,” McGregor advises, adding users should think of whether they want to keep the equipment in the lab or on the production line and where they want to position it in the facility. Calling vendors and asking for product demos, whether through videos or in-person classes, is also important.
Instruments Used in a Personal Care Lab:
- Texture analyzers
- HPLC systems
- Microbiology instruments to test for things such as bacteria and fungi
“The bottom line for these lab managers is, ‘How can I continue to support the increasing volume of samples that I’m being asked to test every day with no increase in lab staff and how can I get more out of the instrumentation so that I don’t need human resources to keep expanding to meet these growing requirements?” he says.
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