Reasons for Product Similarity

In the United States, patent protection is extended to the original inventor company for 17 to 20 years, depending on the application date.  After this time elapses, other manufacturing companies are permitted to produce the active ingredient.  Although the generic active must be approved by the Environmental Protection Agency as being chemically similar to the original, registered active ingredient, Bayer scientists have identified significant differences between their own active ingredients and some of those made by generic suppliers, (i.e, impurity levels, color, pH, melting point, and crystalline morphology).

When a generic producer wishes to purchase from this new source of active ingredient for its own product, the formulation is often targeted as the same type (e.g., powder, granule, suspension concentrate, etc.) and often contains the same level of active ingredient originally registered with the branded product.  Why might a generic manufacturer attempt to copy the branded product formulation?  One key reason is simply to produce a quick look-a-like formulation that is already accepted in the marketplace.  Also, since the generic formulation appears much the same as the branded product, the regulatory approval process can be hastened by reference to the specific use instructions and mixing rates already established from the branded product. 

 What you can’t see makes the difference

 Basic manufacturers, such as Bayer, produce or internally certify the quality of each of their own high purity active ingredients. They also invest millions of dollars to secure the latest equipment and instrumentation for the chemist to optimize the formulation to its fullest potential. It is this optimization process that can make the difference between a product simply being applied to the pest site, versus interacting within the full environment to control the intended pest as quickly and completely as possible. 

Most formulation chemists agree:  it is fairly simple to produce a basic formulation that “looks good in the bottle” and is relatively stable as it sits on the shelf. All formulators use the same basic processing equipment to measure, mix and mill the active ingredients with the inert ingredients that comprise a particular formulation type.  However, the real technology that often determines the effectiveness of a product occurs several years prior to the first date of sale. At that time a basic manufacturer decides to produce a specific formulation type (i.e., suspension concentrate, water dispersible granule, emulsifiable concentrate, oil in water dispersion) which will exhibit the exact properties required to address a specific market objective. 

Basic manufactures can easily spend hundreds of man days and several hundred thousand dollars optimizing each formulation with the designed properties to make the active ingredient as efficacious as possible. Unlike the active ingredient, a proprietary formulation technology is rarely applied for patent protection but is instead maintained by the basic manufacturer as strictly confidential, without expiration.

One way to explain how formulation technology can benefit the end-user was demonstrated during a spray application study conducted by researchers at The Ohio State University.  In this study it was discovered that up to 90 percent of the pesticidal spray droplets applied to soybean leaves was lost due to simple runoff. In similar tests, Bayer’s own high speed photography was used to clearly demonstrate (Figure 1) how droplets of non-optimized formulations can strike the waxy leaf cuticle and simply fall off, becoming unavailable for plant protection. 

 Adding Additives

 To prevent this droplet repulsion phenomenon, the formulation chemist can incorporate special surface active agents (surfactants) into a formulation that effectively reduce the droplet’s dynamic surface tension and thus dramatically reduce droplet runoff.  If necessary, other well-researched additives are incorporated into the formulation to allow:

• maximum leaf contact (droplet spreading)
• rapid cuticle penetration and uptake to improve efficacy and  rainfastness
• quicker activity resulting in reduced pest damage (Figure 2).  

Additional studies are conducted to measure the particle size and shape of the active ingredient as it dries and binds to the leaf surface. This is carried out by scanning electron and florescence microscopy (Figure 3), along with direct biological assays that correlate surface characteristics with field performance. 

For soil-applied granules or fertilizer formulations, the chemist may incorporate specially designed emulsifiers that allow rapid granule release with small amounts of rainfall or soil moisture (Figure 4).  Should longer residual activity be required, the chemist may encapsulate the granule in a polymer coating that allows for slower or sustained release of the active.  At Bayer, these specific release mechanisms can be measured from granular or foliar-applied formulations using florescence microscopy, and autoradiography (using radio-labeled active ingredients - Figure 5), along with a wide range of other analytical techniques.

While most of these formulation optimization activities occur inside the laboratory, basic manufacturers test their final formulations under actual field and glasshouse conditions. Bayer conducts its formulation technology screening at one of 25 research farms around the world, as well as at its dedicated Development and Training Center located in Clayton, N.C. 

At Clayton, more than 40 different cultivars of turfgrasses are maintained exclusively for new active ingredient and formulation screening. Only after the formulation has been tested by staff entomologists, pathologists, or weed scientists, and over two growing seasons, does it consider a formulation “optimized for commercial sale.” 

It Pays to Be Informed

 An optimized formulation must deliver the active ingredient to the target in the physical form and at the threshold level and timing required to control the pest. Today’s golf course superintendent is armed with options and knowledge never before available.    It is well demonstrated that products containing similar active ingredients are often not equivalent in their ability to effectively control diseases, pests or weeds. This difference is almost always attributed to the formulation technology that was used to development the product.

At Bayer, we continue to enhance the performance of our older active ingredients in much the same way we work with newer active ingredients in our pipeline. Often previously optimized formulations must be altered to add specific characteristics to better control a specific pest, to add tank mixing properties with fertilizers or other pesticides, or simply to make the product safer to the end-user. We employ more than 180 formulation chemists worldwide to constantly improve formulations by examining each inert ingredient and its role in the formula.

For the formulation chemist, an optimized formulation is never truly achieved!

Formulation Technologies used by Bayer Formulation Chemists:

• Particle Size Optimization of the active ingredient as determined by use of scattered laser refractometer and often scanning electron microscopy
• Absolute Rheometer to determine the visco-elastic properties of a formulation for predicting shelf stability and ease of dilution into water
• Dynamic Surface Tension measured with Tensiometer to determine if the spray product will adhere to or simply repel from the leaf surface upon application
• Florescence Microscopy to determine how the droplet adhers to and spreads along the leaf surface
• Special adjuvant additives to dramatically increase droplet spreading or penetration into a leaf or onto an insect by the addition of special surface active agent “surfactants” to the formulation
• Autoradiography to determine the level of the formulation that has moved into the plant tissue
• 2 season Glasshouse and Field Screening to define formulation performance under actual growing conditions