Compounding Pharmacies and Bacterial Endotoxin Testing

Compounding Pharmacies and Bacterial Endotoxin Testing

With guidelines changing, some helpful tips for compounding pharmacies on endotoxin testing requirements  

The time is quickly approaching for the revised USP <795> and <797> chapters to be effective for compounding pharmacies. You may be asking what changes you must make to ensure compliance with these new regulations regarding quality control testing. Or what does this mean in terms of adherence to endotoxin testing requirements, or why do I even need to test for endotoxins.  We already perform sterility testing, isn’t that enough? The answer to your questions and more will be explained below.  

Compounded sterile preparations (CSPs) are currently categorized as low, medium, and high risk but the designations will change to Category 1, 2 and 3.  Along with a new naming convention, the factors used to determine which CSPs belong in each category will also be new and exciting. The first order of business will be to assess what category your product will be in when these changes go into effect to ensure full compliance with QC testing requirements. Depending on what you are compounding, the category could stay the same. If your product now needs to be tested for endotoxins, you might have some questions and concerns about how to do this and why it is even needed.  

Why test compounding products for endotoxins?

Now we can tackle the question of why we need to test for endotoxins. Endotoxins are complex lipopolysaccharides (LPS) that are a major part of the Gram-negative bacterial cell wall. When present in low concentrations, these components induce inflammation and fever. However, septic shock and even death can occur when LPS molecules are present in high concentrations. A good question some of you may now be wondering is, “If sterility is already required why do I need to perform endotoxin testing. Isn’t it almost the same thing?” The simple answer is that even with a negative sterility test, endotoxins can still be present in your product.  

The bacterial endotoxin test (BET) uses Limulus amoebocyte lysate (LAL), which is an aqueous extract derived from horseshoe crab blood. This type of testing has historically been challenging and time-consuming to perform in-house. Whether you are considering employing a contract lab for testing or bringing it in-house from a test supplier there are many methods to consider. Traditional kinetic chromogenic LAL methods using 96 well plates and an absorbance plate reader require pipetting and technical skills that take time to become proficient at performing. While gel-clot LAL is available and is a low-cost alternative, it too requires technical skill. Moreover, the results are subjective, and the results do not meet basic data integrity requirements. Both methods are compendial globally and give results in about an hour.  

Recombinant technologies are an option if you have sustainability objectives and want to eliminate the use of animal products. They are also run with 96 well plates using either kinetic chromogenic or fluorescence methods. Recombinant technologies are not compendial globally and require alternative method validations in most cases.  

An easier endotoxin testing method

Is there an endotoxin testing method that is easy to use, compendial globally, meets data integrity requirements, and provides fast, quantitative results? Why, yes, thank you for asking! Charles River Laboratories’ cartridge technology is designed to eliminate costly specialized training and streamline testing using only 100 µl of sample.  The cartridge system uses the kinetic chromogenic test methodology and a microfluidic cartridge to give real-time quantitative endotoxin results in about 15 minutes. All the required reagents are loaded onto the cartridge so there are less consumables used and no reagent waste. All of these benefits make cartridges an easy, compliant, robust, and rapid solution for compounding pharmacies. You can find more information here.

The revisions to these chapters are a step in the right direction for the future of pharmaceutical compounding and help us ensure the medicines that are produced in this manner are safe for patients. While endotoxin testing can seem difficult to perform and manage in-house, the benefits outweigh the hurdles. By partnering with experienced, proven leaders in the industry this can be accomplished with ease and your lab will be able to fulfill regulatory expectations effortlessly.