How Arkopharma improves shelf life in plant-based supplements

When French Doctor Max Rombi co-founded Arkopharma in 1980, his philosophy was not exactly en vogue. His belief that most health problems are caused by poor diet—and that plants and natural substances could help relieve them—was considered old-fashioned at the time. 

More than forty years later, Arkopharma manufactures and releases nearly 300 health products in Europe and throughout the world. The company’s natural health solutions include vitamins, minerals, royal jelly, beauty products, food products, and more. And accurate water activity measurements are essential to their success.

Water Activity and the Formulation Process

Fabienne Letournel-Perreau, a French research and development team manager at Arkopharma Laboratories, has worked in Arkopharma’s pharmaceutical laboratory for more than thirty years. She and her colleagues measured moisture content for a long time as part of their research and development. But before they started using the Vapor Sorption Analyzer (VSA), they didn’t fully understand the relationship between water activity and product stability.

“We considered [moisture content] a factor of degradation in products,” Letournel-Perreau says. “But it wasn’t. Sometimes degradation did not occur despite an increased moisture content. So the concept of moisture content related to water activity has been clear. Once we started to use the Vapor Sorption Analyzer, we realized that water activity and moisture content have to be taken into account together. And this understanding improved our formulation process and our ability to predict stability. It was very, very important to understand that."

Measuring Stability and Predicting Shelf Life 

Letournel-Perreau and her colleagues use water activity measurements to ensure product quality. But the Vapor Sorption Analyzer (VSA) doesn’t only give Arkopharma a competitive advantage. The data they receive from the VSA also helps them comply with regulations.

“There’s a difference between medication and food supplements,” Letournel-Perreau says. “But because we have to give evidence of the quality and stability of food supplements, we must run the conventional stability study.”

This stability study can take up to five years and requires a significant investment of time and resources. Accurate measurements are essential to the study’s success.

“We have been collecting a huge number of analysis data from stability studies conducted for more than twenty years,” Letournel-Perreau says. “Sometimes this knowledge helps us to forecast the stability of a new formulation; sometimes it doesn’t. So the predictive stability is very useful to anticipate the loss of active ingredients in the formulation over time. This predictive stability is part of the formulation process. So the test results of the predictive stability can lead us to change the formulation so you save time, and money, of course. And therefore, we are more confident about the stability of the finished product. … It’s a big benefit for our company in time and money, and it helps us to feel more confident about the stability of the formulation of the product."

Critical Points of Quality Change

Because every product is different, not all data points are equally useful. At Arkopharma, they refer to the most important data sets as “critical points.” Measuring water activity helps Arkopharma focus on these critical points as they develop products.

“The most critical points for our products are [those that influence] caking and the change of color or odor,” Letournel-Perreau says. “But the most difficult challenge to overcome is the hygroscopicity of the products, because we use natural raw materials. … We try several formulations and put the prototypes in climate chambers so we can select the best formulations. But we also use the moisture resistor kit and the mixing ingredient to get the total final isoterm of the different formulation. It saves time, and we can select the perfect formulation."

A Competitive Edge for the Future

Over the last four decades since Arkopharma was founded, the food supplements market has grown significantly. Companies must innovate to remain competitive. 

“We are working on a lot of new projects and new raw materials,” Letournel-Perreau says. “So it’s very important for my team to upgrade its skills in predictive stability. We want to get where we’re working harder on this topic."