Potency Testing Benefits and Requirements
Potency testing measures the concentration of the active pharmaceutical ingredient (API). This essential test ensures the API concentration matches its intended amount and provides value-added benefits to pharmacies including:
- Supports product compliance checks
- Establishes compounding process controls
- Confirms a preparation is accurate and precise
- Provides documentation references for regulatory audits and patient questions
- Supports sales tools demonstrating a dedication to quality
Potency Testing Requirements
United States Pharmacopeia (USP <797>)
USP <797> requires compounding pharmacies to have written procedures for identity and strength verification tests:
- Certify that labels of drug products include correct names and concentrations of ingredients, total volume, beyond use date, appropriate route of administration, storage conditions, and other information for safe use
- Compare compound record to original prescription for correct identities, purities, and amounts
- Verify correct fill volumes and correct number of units were obtained
When the strength cannot be confirmed to be accurate,
based on the above three inspections,
the products should be tested by methods specific for the active ingredients.
Even if potency testing is not required, potency testing is recommended to ensure compounded drug products meet quality standards.
Food and Drug Administration (FDA) 503B Outsourcing Facilities
The FDA interim guidance requires 503Bs to perform identity and strength verification tests for each batch:
- Identity test can be the same test as the strength test
- For batches < 10, allows testing on every other batch for identity and strength, or every batch bringing the total units made to 10
- For aqueous solutions, testing for identity and strength can be performed on the bulk solution just before filling the finished drug product containers
Potency testing assures that compounded drug products meet the FDA safety requirements and have the identity and strength characteristics that the drugs claim to possess.
ARL Potency Test Methods
A potency test method separates, identifies, and quantifies compounds present in a sample. ARL frequently uses high-performance liquid chromatography (HPLC), ion chromatography (IC), and gas chromatography (GC) to measure API concentration by comparing a known reference standard at a known concentration to the sample (drug substance or product). USP has established that the acceptable range of most compounded drugs is ± 10%; however, it can be as great as ± 20% (as with some proteins) or as tight as ± 5% (as with potent analgesics). Pharmacies may also specify an acceptable range based on their compounded formulation.
Contact ARL for more information 405-271-1144 or email@example.com to request a quote.
Q&A with Dr. Kupiec, Part 2
Over the next few months, we will sit down with Dr. Thomas C. Kupiec, President and CEO, for a Q&A to learn more about the evolution of ARL Bio Pharma over the past 20 years.
- What was the industry like when ARL Bio Pharma began? "Compounding has been around for centuries, extemporaneous preparations, creating a pharmaceutical elegant product or preparation that can be administered to the patient. In the 90s, the industry started to see an increased awareness among physicians and patients as to the benefits of personalized medications. Utilizing safe conditions to make the preparation is very important. Twenty years ago, we provided basic potency and sterility testing for inhalation solution products. It's very interesting throughout these 20 years, compounding has changed quite a bit and ARL continues to expand our testing services and quality to ensure that a safe and quality product is there."
- How does ARL Bio Pharma stay current in the compounding and pharmaceutical industry? "Over the years, probably every 12-18 months, we evaluate where we've been and look at continuous improvement. I think you look at risk and evaluate those. You try to design the processes and procedures to handle those risks. I think that as you go through this journey, just the process of traveling through the journey enables you to have lessons you can benefit from in the future. The science has changed with the evolution of biologics, pharmacogenomics, DNA, microbial identifications through sequencing to new market segments. The science is changing, the market is changing, regulation is changing, the business is changing and if you're not willing to change, we get left behind!"
- What was the main challenge when you started ARL? "It was financially challenging. As a business owner, I worked three jobs when I acquired ARL. I worked as an adjunct faculty member, forensic toxicologist, and pharmaceutical scientist."
- Do you think regulatory requirements have changed compounding over the last 20 years? "Yes. I think regulatory has definitely had an effect on compounding. There is this balance. During the past year, I've been thinking of compliance vs. science. The important issue of balancing between science and compliance and then taking that to the next dimension and balancing between the patient, pharmacist, physician triad. You want to give the patient, the safest, highest-quality drug preparation or product that is effective. At the same time, you don't want so many restrictions that inhibit patients from receiving medications. Balance is the key and the challenge."
- For you, what have been the greatest developments in compounding and pharmaceutical sciences over the last 20 years? "There are many developments that have occurred in pharmaceutical sciences. In vitro/In-vivo (IV/IVC) correlation, modernization of USP monographs, modernization of analytical techniques, and automation are just a few. I also have an inherent bias towards the area of pharmacogenomics, the study of genetics and its role in individual drug responses. We have a pharmaceutical testing company, a genetic testing company, and a forensic think tank. Pharmacogenomics is a natural pathway."
Join us next month as we continue our Q&A with Dr. Kupiec and dive into what the future of ARL looks like.
Have you celebrated ARL's 20 years with 20% off?
To thank you for making our success possible, ARL is offering customers:
- 20% off USP <71> Sterility Tests method suitability
- 20% off USP <61> Microbial Enumeration Tests method suitability
- 20% off USP <51> Antimicrobial Effectiveness Testing method suitability
This discount is good through December 31, 2018.
Contact ARL for more information 405-271-1144 or
to request a quote.