Corporate-university partnership yields a guide on establishing the stability of chemical products

At book launch, a Brazilian researcher presents the parameters and methodologies to establish standard expiration dates for chemical products for the industrial sector.

By Noêmia Lopes

Agência FAPESP – The lack of criteria for determining the precise shelf life of chemical products is a recurring problem in the chemicals industry.

On December 10, the book Shelf Life para a Indústria Química [Shelf life for the chemicals industry] was launched to do just that: find a solution to determining shelf life and address the lack of consistent periodical analyses for establishing shelf life beyond the expiration date for products that are unopened.

The book details which tests should be conducted in stability studies, which will then indicate for how long a given chemical substance meets the minimum quality and applicability requirements.

The tests include factors related to temperature, humidity, light and packaging, for example, and could be applied in the production lines of various sectors of the chemical industry.

The studies that led to the book were conducted during the doctoral studies of Luciana Rodrigues Oriqui under the supervision of Milton Mori, a professor at the School of Chemical Engineering at Universidade Estadual de Campinas (FEQ/Unicamp), and with co-mentoring by Pedro Wongtschowski, a chemical engineer and member of the Board of Directors at Ultrapar, which operates in the chemical specialties segment.

“We had conversations to find a relevant theme (from the academic point of view) that, at the same time, would offer solutions to a problem in the Brazilian chemical industry. The problem that emerged was determining shelf life, which is still much more an art than science – and we wanted to make it more science and less art,” said Wongtschowski at the launch of the book.

Among the consequences of this lack of knowledge is the disposal of products that might have longer shelf lives, causing financial losses, raising the final price of the product and often resulting in environmental damage.

Imports and exports

According to the authors, the book should also help importers and exporters of chemical products. For importers, it is not uncommon to receive merchandise without a pre-established expiration date because many countries do not require this type of labeling. In addition, the Consumer Defense Code establishes that every product commercialized in Brazil must have its expiration date on the label, making stability studies necessary.

For exporters, the stumbling block is the lack of clear parameters to meet the demands of European regulations, such as Registration, Authorization and Restriction of Chemicals (Reach), and, in doing so, ensure certain markets. “Without standardization, producers, importers and exports get lost,” commented Mori.

In the book, Oriqui, Wongtschowski and Mori highlight that in 2012 the chemical products sectors were responsible for 19% of Brazil’s total imports and 6% of its total exports. In the first four months of 2013, there was a 7.1% growth in the national consumption of chemical products of industrial use, raising imports by 29.4%.

Research stages

The field studies conducted by Oriqui, which involved visits to chemicals, pharmaceutical, cosmetics and foodstuff industries, confirmed the demand for specific stability studies for chemical products.

“I realized that in regard to stability studies, the pharmaceutical industry is among the most rigorous and best regulated in the market. It is much more established and applies the best defined methods to determining how the quality of products changes under the influence of factors such as temperature, humidity and light,” she explained. “For this reason, the parameters that we used in our guide are inspired by the practices adopted by the pharmaceutical industry.”

Oriqui recalls that in that stage, she was sought after by chemicals industries interested in methodologies to define shelf life and additional expiration dates. “Tests conducted on products that would have been expired – flavorings, for example – often revealed that their properties were still intact. In this case, disposal or incineration causes economic losses and environmental damage that must be prevented,” she affirmed.

In this regard, chapter 5 of “Shelf Life” presents an adaptation of the standards adopted by the pharmaceutical industry from international bodies such as the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH).

The result is a guide adapted to the reality of the chemicals industry, which offers detailed step-by-step instructions for assays of temperature, humidity, conditioning, storage, statistical analysis and labeling.

“By following the steps of a retest after the degradation of a product, one can verify its characteristics and utilize the established parameters to determine its shelf life – 30% to 50% of the original expiration date, for example,” explained Oriqui. “We will adapt these parameters while we develop tests in laboratories in the next stage of the study, which will require at least 30 months of work.”

Oxiteno, of the Ultra Group, and Nanotimize Tecnologia Ltda. are funding the project, which will continue as part of Oriqui’s post-doctoral studies, again under the guidance of Mori and Wongtschowski. Four chemical products – each representing one of the pharmaceutical, cosmetics, foodstuff and other industry sectors (such as oil, leather, paint and pesticides) – are being tested to extend the conclusions of this research to other similar substances.

According to Oriqui, “the idea is to guarantee more robust and agile efforts in the revalidation of products. To this end, we are utilizing chemometrics, a scientific discipline that couples statistical studies and chemical analysis, as well as miniaturizing analytical instruments.”

According to the authors, the methodology should allow for the development of a map correlating the analytical data collected in the laboratory to the results obtained when a product is submitted to infrared analysis in the field. “The ranges on this map will make it possible to revalidate chemical products in loco, at the industry site, and even packaged goods,” said Oriqui.

Average kinetic temperature

Another partner in Oriqui’s research was the National Institute for Space Research (INPE) Weather and Climatic Studies Center (CPTEC), which helped to validate the parameters established for the stability studies in the climatic zone where Brazil is located.

“Our country is in a region known as IVB, where bodies such as ICH and the World Health Organization (WHO) established 30 °C as the standard temperature for this type of study,” affirmed the researcher.

The average kinetic temperature that was adopted consistently throughout the investigation simulates the same effect of the temperatures that occur in a location throughout the year. “By using CPTEC/INPE’s 20-year database, we validated 30 degrees Celsius and 75% air humidity as the worst possible scenario that a product would face in Brazil. Stability tests should be conducted under these conditions and not at room temperature, as is common,” explained Oriqui.

• Shelf Life para a Indústria Química [Shelf life for the chemicals industry]
  Authors: Luciana Rodrigues Oriqui, Milton Mori and Pedro Wongtschowski
  Release: 2013
  Price: R$ 41.90
  Pages: 152
  More information: www.elsevier.com.br/site/produtos/shelflife.