// May 12, 2016

Working Together to Protect Over-the-counter Medicine Quality: Microbial Testing

Quality of OTC Medicines

Over-the-counter (OTC) medicines, drugs available to consumers/patients without a prescription, play an important role in our modern healthcare system. Currently, there are more than 800 OTC active ingredients found in more than 100,000 OTC medicines in the marketplace. Research indicates that 93% of US adults prefer to treat minor ailments with OTC medicines before seeking professional care.[1]

To help protect the quality of OTC medicines and the patients using them, USP has been working with FDA, industry and related organizations to help ensure that public standards for OTCs reflect innovation/changes in healthcare and the marketplace. An important component of this effort is educating manufacturers and others involved in OTC product development and design, including testing and packaging, about the latest standards and best practices.

To this end, the Consumer Healthcare Products Association (CHPA), a national trade association representing manufacturers of OTC medicines and dietary supplements, is producing a series of workshops on key issues related to OTC medicine quality. For example, in its May 17-18, 2016 Product Stability: Microbiological Testing Workshop, CHPA has collaborated with experts from USP and other OTC stakeholder groups to provide an inside look at microbiological testing guidelines, requirements, data and protocols specific to the OTC sector.

According to John Punzi, Ph.D., CHPA Director of Quality and Technical Affairs, this is a “priority topic for our members who frequently turn to CHPA for information on current industry practices and applicable OTC standards and guidelines.”

Microorganisms and Importance of Product Stability Testing

Microbiological testing determines the presence and type of microorganisms—living microscopic organisms such as bacteria and fungi—which could be present in a finished drug product.

“Depending on the type and quantity, microorganisms can impact the quality, stability, safety and efficacy of an OTC drug,” notes Radhakrishna Tirumalai, Ph.D., USP Principal Scientific Liaison, one of the presenters at the CHPA workshop. “These ‘bugs’ tend to find homes where there are gaps in quality, in things such as water, ingredients, equipment, and poor packaging and storage conditions. Once they are present and the conditions are favorable, microorganisms can quickly multiply, produce toxins and breakdown a drug product. Not only can they have deleterious effects on the product, they can also have deleterious effects on the patient.”

A key way to ensure that microorganisms are not present in amounts and types harmful to the drug and patient is to test for them. USP offers official public standards for such testing, some of which are mandatory requirements enforced by FDA for OTC drugs. Dr. Tirumalai and the other presenters at the CHPA workshop will discuss key components of relevant USP standards, including USP General Chapters <51> Antimicrobial Effectiveness, <61> Microbial Enumeration Tests for Drug Substances and Drug Products, and <62> Tests for Specified Microorganisms in Drug Substances and Drug Products.

In addition to the basics of microbiology and purpose of microbiological testing, the workshop will cover test method suitability and validation, assigning appropriate microbiological acceptance criteria, stability program design and execution guidances, managing data deviations and data integrity.

Value of Collaboration

The CHPA workshop is one example of how key stakeholders are collaborating to help safeguard OTC drug quality. As Punzi notes, “The workshop affords attendees an opportunity to benchmark their practices against other companies in attendance. To learn how best practices are being implemented and discuss how USP standards are being interpreted from the variety of drug manufacturers in attendance is of great value to the OTC community.”

Likewise, the collaboration is helpful to USP. Contributing to CHPA’s workshop affords USP another way to learn about issues and needs specific to OTC manufacturing and testing. According to Tirumalai, “This collaboration can help inform our standards-setting process which aims to ensure the identity, strength, quality and purity of OTC medicines and, ultimately, benefit the patients that use them.”

To learn more about or to attend the workshop, visit the CHPA OTC Academy website. For additional information or questions about USP’s standards for microbiological testing, please contact Dr. Tirumalai at rst@usp.org.