Advancing Analytical Testing Techniques

Felicity Thomas;

Advancing Analytical Testing Techniques

Published on: July 5, 2024

Pharmaceutical Technology, Pharmaceutical Technology, July 2024, Volume 48, Issue 7

Pages: 18–19

Although advancements in analytical drug substance testing are being made, the increasing diversity of the therapeutic landscape is necessitating further innovation.

The analytical testing of drug substances is a critical aspect of development and manufacturing within the bio/pharma industry. These comprehensive tests are used throughout the drug development lifecycle to ensure each product used within a therapy is safe and effective for use, and of the highest quality. To learn more about drug substance testing, Pharmaceutical Technology® spoke with Pavan Kumar Kunala, global biologics lead, Almac Sciences, and Sander Kok, PhD, director Analytical Sciences at Ardena.

The role of substance tests

PharmTech: Could you run through the role of drug substance testing for bio/pharmaceuticals and the types of tests generally used?

Kunala (Almac Sciences): The analytical methods for drug substances play a pivotal role in the journey of biologics development, from the early clinical phase to commercialization, ensuring that the product meets the highest standards of quality, safety, and efficacy for therapeutic use. Moreover, some of the drug substance [DS] methods are instrumental in testing in-process samples, providing insights into process development and ensuring that manufacturing remains consistent and robust during the early phases of product development. The characterization of the [DS], which involves understanding the critical quality attributes (CQAs) and selecting appropriate orthogonal analytical methods to assess them, is another vital application of these methods. Additionally, these methods are employed in the release and stability testing of the bulk [DS], thereby ensuring consistent quality across different batches. (See Sidebar for a link to a detailed review of drug substance test categories.)

Kok (Ardena): Typical tests in a drug substance analytical laboratory consist of in process control, release, and stability testing of DS batches. In the pre-clinical phase, analytical methods are developed, including forced degradation and robustness tests. In terms of methodologies, DS tests include at least the methods to verify identity, assay and impurities following [the] ICH [International Council for Harmonisation] Q6A guideline.

Technological advances and novel approaches

PharmTech: Have there been any technological advances or novel analytical approaches that are helping to improve efficiencies in drug substance testing?

Kok (Ardena): For many years, ultra-high pressure liquid chromatography (UHPLC) has brought the pharmaceutical analytical community additional separation power and reduced analysis time. Particularly the strong improvement in resolution compared to conventional HPLC enabled a further and detailed characterization of drug substances with a complex impurity profile.

Kunala (Almac Sciences): Certainly, the advent of advanced analytical techniques is boosting the testing efficiency of biologic drug substances. For example, the use of next-generation sequencing (NGS) in identity testing of mRNA [messenger RNA] therapeutics brings significant improvements in efficiency. Traditional methods for identity testing often involved time-consuming and laborious processes such as Sanger sequencing or mass spectrometry. In contrast, NGS can process millions of sequences concurrently, drastically reducing the time required for comprehensive analysis. This high-throughput capability allows for rapid identity confirmation, accelerating the pace of mRNA product development and production.

Similarly, the use of nucleic acid testing (NAT) methods for mycoplasma testing have shown significant benefits over traditional culture methods in terms of efficiency for cell and gene therapy products. NAT-based methods are highly sensitive, specific, and can provide results within few hours, whereas culture methods often require weeks to grow and identify mycoplasma colonies. This rapid turnaround time is particularly advantageous for cell and gene therapies, where time is of the essence. It enables prompt detection of contamination and immediate intervention. Furthermore, the timely identification of mycoplasma contamination can prevent substantial financial losses.

A challenging therapeutic transformation

PharmTech: What are the main challenges in terms of drug substance testing nowadays given the evolving therapeutic landscape?

Kok (Ardena): More and more highly potent drug substances are of interest to our clients. This brings a challenge to create a safe work environment: not only to prevent cross-contamination towards subsequent manufacturing campaigns, but of even importance is the containment of these highly potent materials from the operators and analysts. Patient and employee safety is of high importance.

Another important and challenging subject is the quantification of potential genotoxic impurities (PGI). As PGIs are frequently highly reactive, a careful approach is needed in the development of a reliable, quantitative analytical methodology. Detection of low levels [of PGIs] are required, and this [necessitates] analytical creativity in sample preparation, separation, and advanced detection techniques to meet the strict [regulatory] requirements.

Kunala (Almac Sciences): The evolution of newer biologic modalities is transforming the landscape of treatment options available to patients, offering more effective and targeted therapies for a wide range of diseases. This is a significant step forward in the pursuit of personalized medicine and improved patient care. However, this changing therapeutic landscape presents its own challenges.

For example, analytical ultracentrifugation (AUC) is a widely used analytical technique for determination of empty and full capsid ratios in adeno-associated virus (AAV)-based gene therapies. AUC is favored for its high-resolution capabilities and minimal sample preparation requirements. However, the deployment of AUC in a good manufacturing practice (GMP) environment for the release of AAV therapy drug substances present considerable challenges. These [challenges] include limited availability of instrumentation models that could be used in a quality control laboratory, instrumentation software which may not be fully compliant with current data integrity standards, and the complexity involved in training analysts in the comprehensive workflow of data analysis.

[Additionally], the diversity of biologics, ranging from long-peptides and proteins to complex monoclonal antibodies and gene therapies, complicates the establishment of universal standards for characterization of impurities. The lack of specific limits for the reporting and identification of impurities in biologics presents a significant regulatory challenge, given the potential impact of these impurities on the safety and efficacy of the biologic.

As we continue to innovate and develop new dosage forms and therapeutic modalities, the analytical techniques and tools we use to test these substances must also evolve to comply with current regulations.