The transfer of analytical procedures

Automated ELISA for potency measurements of therapeutic antibodies and antibody fragments

Potency assays are essential for the development and quality control of biopharmaceutical drugs, but they are often a time limiting factor due to manual handling steps and consequently low analytical throughput. On the other hand, automation of potency assays can be challenging due to their complexity and the use of biological materials. ELISA (enzyme-linked immunosorbent assay) is widely used for potency determination and is a good candidate for automation as all ELISA types depend on the same basic steps: coating, blocking, sample incubation, detection, and signal measurement. Nevertheless, ELISA for relative potency measurements still require drug-specific development and assay validation thereby complicating automation efforts. To simplify potency testing by ELISA, we first developed a manual protocol generally applicable to different drugs and then adapted this protocol for automated measurements. We identified unexpected critical parameters which had to be adapted to transfer the manual ELISA to an automated liquid handling system and we demonstrated that gravimetric sample dilution is unnecessary with the automated protocol. Both manual and automated protocols were validated and compared using multiple biotherapeutics. The automated protocol showed similar or higher precision and accuracy when compared to the manual method.

Changes in the cis-trans isomer selectivity of a reversed-phase liquid chromatography column during use with acidic mobile phase conditions

Reversed-phase liquid chromatography (RPLC) is the analytical tool of choice for monitoring process-related organic impurities and degradants in pharmaceutical materials. Its popularity is due to its general ease-of-use, high performance, and reproducibility in most cases, all of which have improved as the technique has matured over the past few decades. Nevertheless, in our work we still occasionally observe situations where RPLC methods are not as robust as we would like them to be in practice due to variations in stationary phase chemistry between manufactured batches (i.e., lot-to-lot variability), and changes in stationary phase chemistry over time. Over the last three decades several models of RPLC selectivity have been developed and used to quantify and rationalize the effects of numerous parameters (e.g., effect of bonded phase density) on separation selectivity. The Hydrophobic Subtraction Model (HSM) of RPLC selectivity has been used extensively for these purposes; currently the publicly available database of column parameters contains data for 750 columns. In this work we explored the possibility that the HSM could be used to better understand the chemical basis of observed differences in stationary phase selectivity when they occur - for example, lot-to-lot variations or changes in selectivity during column use. We focused our attention on differences and changes in the observed selectivity for a pair of cis-trans isomers of a pharmaceutical intermediate. Although this is admittedly a challenging case, we find that the observed changes in selectivity are not strongly correlated with HSM column parameters, suggesting that there is a gap in the information provided by the HSM with respect to cis-trans isomer selectivity specifically. Further work with additional probe molecules showed that larger changes in cis-trans isomer selectivity were observed for pairs of molecules with greater molecular complexity, compared to the selectivity changes observed for simpler molecules. These results do not provide definitive answers to questions about the chemical basis of changes in stationary phase chemistry that lead to observed differences in cis-trans isomer selectivity. However, the results do provide important insights about the critical importance of molecular complexity when choosing probe compounds and indicate opportunities to develop improved selectivity models with increased sensitivity for cis-trans isomer selectivity.

Development of the general chapters of the Chinese Pharmacopoeia 2020 edition: A review

The Chinese Pharmacopoeia 2020 edition was reviewed and approved by the National Medical Products Administration and the National Health Commission of the People's Republic of China in July 2020. The current edition was officially implemented on December 30, 2020. The general chapters of the Chinese Pharmacopoeia discuss the general testing methods and guidelines, which are the common requirements and basis for the implementation of drug standards in the Chinese Pharmacopoeia. Owing to adherence to the principles of scientificity, versatility, operability, and sustainable development, there is an improvement in the general chapters of the 2020 edition over those of the previous editions. Further, the application of advanced and mature analytical techniques has expanded, the development of testing methods for exogenous pollutants in traditional Chinese medicines has been strengthened, and technical requirements are now better harmonized with international standards. The updated edition provides technical and methodological support to ensure safety, effectiveness, and control of pharmaceuticals in China and will play an important and active role in encouraging the application of advanced technologies, improving the quality control of medicines, and strengthening the means of drug regulation in China. This review provides a comprehensive introduction of the main features of and changes to the general chapters in the Chinese Pharmacopoeia 2020 edition and aims to provide reference for its correct understanding and accurate implementation.

Method Transfer Evaluation for Digital Derivative Spectrophotometry Through its Resolution Parameter Comparison of Different Computer Programs

The application assessment of different programs was performed with equivalence tests for method transfer pro second-order derivative spectrophotometry. The digital second-order derivative spectra were calculated on different instruments; GBC Scientific Equipment Cintra 20 (Cintral v.2.6 and Spectral v.1.70 software programs) and Thermo Scientific Evolution 300 (VISIONPro software) were analyzed using the amplitude A/B ratio (A = ²D_265,263; B = ²D_263,261). Amplitude A/B ratio is the resolution parameter for derivative spectrophotometry prescribed in European Pharmacopoeia. The obtained values for A/B ratio were either very similar or significantly different among programs: 0.669 (Cintral v.2.6), 0.549 (Spectral v.1.70), 0.556 (medium indirect VISIONPro), 0.557 (one-step Savitzky-Golay 7 VISIONPro), 0.689 (two-step Savitzky-Golay 7 VISIONPro). Method transfer was possible between Spectral v.1.70 and VISIONPro (medium indirect and one-step Savitzky-Golay 7), but the values obtained in Cintral v.2.6 were not comparable to the other programs. The absorbance data exported from both instruments were additionally calculated in OriginPro8 which provided almost the same mean A/B values (0.627 Cintral v.2.6; 0.624 VISIONPro), confirming that the two instruments recorded the same zero-order spectra. The calculation of resolution parameter could be used for verification of program comparison, which would enable transfer between sender and receiver laboratory. The accordance between program algorithms was confirmed when acceptable differences for values of resolution parameter (A/B ratios) were achieved.

Developing Robust Standardised Analytical Procedures for Cannabinoid Quantification: Laying the Foundations for an Emerging Cannabis-Based Pharmaceutical Industry

The plant genus Cannabis is a prolific producer of unique pharmaceutically relevant metabolites, commonly referred to as cannabinoids. Robust and standardised methods for the quantification of cannabinoids within botanical and drug forms is a critical step forward for an emerging Cannabis-based pharmaceutical industry, which is poised for rapid expansion. Despite a growing body of analytical methods for the quantification of cannabinoids, few have been validated using internationally accredited guidelines. Moreover, standardised methods have yet to be developed for application at various stages of manufacture as well as for different levels of processing and refinement. Validation parameters for establishing robust standardised methods for cannabinoid quantification within Cannabis-based drug forms are critically discussed. Determining an appropriate level of specificity (discrimination) among heterogeneous botanical matrices as well as evaluating accuracy (recovery) and inter-laboratory precision (reproducibility) within strict and volatile regulatory environments are potential obstacles to the establishment of robust analytical procedures. We argue that while some of these challenges remain unique to Cannabis, others are common to botanical-based drug development and manufacture. In order to address potential barriers to analytical method standardisation, a collaborative research initiative inclusive of academic and commercial stakeholders is proposed.

Robust, fit-for-purpose method transfer: why we should apply equivalence testing

Efficient method transfer is the key in advancing drug candidates through development and requires careful planning and communication between the two laboratories. Successful transfers require robust bioanalytical methods that allow for some small deviations from the method in sender laboratory; however, by keeping the fundamentals of the sender method intact. The equivalence of data produced at both sides should be tested by mutually prepared and analyzed QCs and by analyzing incurred samples at both sides and assessed by a statistical equivalence testing. Current regulatory bodies’ guidances provide very limited direction for experimental setup and evaluation of transfer. This perspective paper gives an overview of the available approaches and proposes a way forward for the bioanalytical community.