At NOW, everything we do is focused on providing you with products of the highest quality. A large part of this involves taking the appropriate measures to ensure that NOW products are not only safe and effective, but also fresh. NOW’s Quality Control and Quality Assurance teams closely monitor all aspects of manufacturing; from the purchasing of raw materials to the day they are packaged and shipped. It is a meticulous, time-consuming process that, in the end, results in a line of dietary supplements and health products of high quality.

Ageless® Oxygen Absorbers
Natural products have four sworn enemies: heat, light, moisture, and oxygen. In addition to a product’s effectiveness, each one of these four conditions can, in its own unique way, threaten the freshness of even the best dietary supplements. As a leader in manufacturing safe, effective natural products, NOW has implemented many processes that make it possible for us to bring you the industry’s freshest natural products. Our use of Ageless® Oxygen Absorbers has proven to be one of the most effective.

Ageless® Oxygen Absorbers consist of small packet inserts that are placed in bottles during the packaging process. They work by absorbing any oxygen that is present after the bottle is filled with tablets, capsules, or Vcaps®. During storage, Ageless® packets continue to absorb oxygen that diffuses through the walls of the bottle.

As the first manufacturer to recognize the importance of incorporating these effective oxygen-absorbing inserts, NOW has been able to significantly reduce the presence of oxygen within oxygen sensitive products. This success has been evidenced by tests that show the elimination of 99.5% of the oxygen within our PETE bottles. PETE bottles are utilized because they are resistant to penetration by oxygen and moisture and in addition are also free of Bisphenol A (BPA). The Ageless® inserts effectively extend product shelf life while maintaining freshness, taste, aroma, and texture. Ageless® packets are especially important for protecting powerful antioxidants. Stability testing confirms their efficacy.

One of the reasons why NOW is so adamant about how we deal with oxygen involves the long-term threat that it presents to some natural products. Just as humans need oxygen to breathe, aerobic bacteria and mold require oxygen to grow and replicate. Without oxygen, they are about as helpless as we would be without it. When they have the amount they need, they are in prime position to grow and thrive off the product in question. In order to help control microbial growth, oxygen levels should be kept as low as possible.

NOW also takes other measures to control the amount of oxygen within our products. These other measures, coupled with our Ageless® Oxygen Absorbers, significantly reduces oxygen levels at the time of packaging. NOW includes Ageless® Oxygen Absorber inserts in products that are most susceptible to oxygen degradation. 

Using Stability Testing to Determine Shelf Life

By Maryann Maloney, Quality Control and R&D Manager, NOW Foods

All NOW dietary supplements have a “Best by” date on them. This date lets consumers know that a product may not meet its label claim after that date.  NOW uses stability testing to determine  the “Best by” date, which also indicates the shelf life of a product.

Stability testing is done on a sample product that is packed in the same container, with all the same inserts and conditions (e.g. storage temperature and humidity) as the finished product that will be sold to consumers. If there is a change to any of these conditions or to the formula, then new stability tests may be needed.

There are two types of stability testing: Accelerated Testing, which tests the product under harsh conditions, and Long-Term or “Real Time” Testing, which tests the product during its projected shelf life.

1.  Accelerated Stability Testing

Samples are placed into an environmental chamber at elevated temperature and humidity for 3 to 6 months.  Typically, this is 40OC (104oF) with a relative humidity of 75%, which would be equivalent to an outdoor heat index of 166oF! These conditions speed up the degradation of the ingredients.  It’s a relatively quick way to find out how stable the ingredients are.  Some ingredients hold up fairly well, others don’t.

The physical integrity of the material may not hold up in some cases.  There may be softening, discoloration, or development of bad odors or tastes.   Because they are caused by harsh conditions, these physical changes do not indicate that there is a long-term stability issue. But they do indicate how a product will fare in a warm, humid environment, not unlike a warehouse in summer.

Typically, testing is done monthly  for 3 months, then again at 6 months. A product is typically assigned a tentative 2-year shelf life or “best by” date based on accelerated data if the ingredients pass the testing.  Long-term or “real time” tests are then run to confirm the results of the Accelerated Stability Testing.

2. Long-term or “Real Time” Stability Testing

Samples are placed into room temperature conditions for the time of the shelf life, usually 2 to 3 years.  This is typically 25^oC (77^oF) with 60% relative humidity. 

Testing is done at regular intervals during this time.  The standard intervals are every 3 months during the first year, every 6 months during the second year, and then annually. At this point, if the testing meets requirements, the  Best by date is no longer tentative and becomes the official shelf life.

Another source of long-term/real time stability data is our “retain samples”. A sample is retained from every packaging run, so there are a lot of historical samples that can be tested at the end of the projected shelf life.  A review of several of these samples can indicate what the actual shelf life is.

Some materials are too fragile for accelerated testing conditions and require real time stability tests. Many products will be subjected to both kinds of tests.

What if the testing fails? 

If a products fails to pass its stability tests, there are several ways to improve its stability to ensure full potency during its shelf life.  The most common improvement methods are:

REFORMULATE – Correct for too little or too much moisture or remove incompatible ingredients.

ADD AN “OVERAGE” – Let’s say we have a 500mg vitamin C tablet and we find that it loses 10% (50mg) of its potency during its shelf life.  We will adjust the formula so it’s made with 550mg.  That way we can ensure that it will still have 500mg at the end of the promised shelf life. 

ADD OR CHANGE INSERTS – Some products absorb moisture from the environment, are easily oxidized or can develop an unappealing odor.  Adding a specific insert (desiccant, oxygen absorber, charcoal packet for odor) may solve the problem. 

Some of the factors that we test for are: moisture, hardness, friability (crumbling, for tablets), potency, disintegration, and undesired microbiological growth.  These are items that may change over time.

A stability testing program is an intensive and long-term commitment, but one that NOW Foods thinks is important.  It is another Element of QualityTM that NOW uses to assure the quality of its products.  NOW’s “A” rating by an independent “third party” GMP (Good Manufacturing Practices) certifying agency is evidence that our company uses reasonable scientific procedures – similar to those used by pharmaceutical companies - for making sound decisions on quality assurance and quality control, including setting appropriate science-based “Best by” dates for its products.