Transfer of analytical procedures: A panel of strategies selected for risk management, with emphasis on an integrated equivalence-based comparative testing approach

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.

Precision of the reportable value-Statistical optimization of the number of replicates

In pharmaceutical analysis, the precision of the reportable value, i.e. the result which is to be compared to the specification limit(s), is relevant for the suitability of the analytical procedure. Using the variance contributions determined in precision studies addressing the levels injection/system precision, repeatability, and intermediate precision, the number of the corresponding replications for analysis/injection, sample preparation, and series/runs can be varied to improve the precision of the mean (reportable) value (Ermer, Agut, J.Chromatogr. A, 1353 (2014) 71-77). However, this calculation will provide only information on the gain for the precision of the calculated reportable value itself. These so-called point estimators have uncertainty associated with them which can be quantified using statistical confidence intervals. Commonly used statistical equations only allow one to calculate confidence intervals for the intermediate precision of the reportable value, which requires that the routine replication strategy must be defined before starting the precision study. In this paper, statistical models are presented that allow optimizing efficiently the replication strategy with respect to the confidence interval of the precision based on the Satterthwaite approximation posterior, i.e. using the results from the precision study without prior knowledge, as for the point estimate. It is further proposed to simplify the model by including only significant variance contributions larger than 20% of the total variation. The advantage of this minimizing the level of nesting is that the upper precision bound will tighten as the level of nesting decreases. This is important as 90% upper confidence bounds are often up to 2 or 3 times the point estimate, even for a larger number of four runs in the precision study. Four models each have been developed both for a 2-fold balanced nested design representing a complete intermediate precision study, and for a 1-fold balanced nested design using injection/system precision from an independent source. An Excel spreadsheet that performs all the calculations in this paper as well as the appropriate model selection is available from the authors. Due to the usually rather low number of series/runs in precision studies, the uncertainty of the reportable value precision is often dominated by the factor runs. For a statistical evaluation of the precision of the reportable value (in case of three precision levels), the authors recommend a minimum of six runs, two preparations per run, and two injections/analyses per preparation, in order to provide sufficient precision of the variance estimates. However, a risk-based approach is recommended for the decision to apply a statistical evaluation of the precision of the reportable value. In case of low patient risk such as for an assay of a well-characterized drug substance with tightly controlled manufacturing and analytical variability dominating the specification range, a point estimator will usually be adequate to demonstrate the suitability of the analytical procedure.

Analytical Target Profile: establishment of precision requirements for assay

Approaches are presented to establish precision (or target measurement uncertainty) requirements to drug substance and drug product assays. They are based on the simple and well-known concept of the normal distribution probability around true content values represented either by manufacturing range limits, or by the manufacturing target (usually 100% label claim). A maximum acceptable precision is derived which allows a defined probability of analytical results within the established acceptance limits of the specification and thus an objective and rational establishment of precision acceptance criteria. By this approach,  α or type-I-errors are controlled, i.e. the maximum probability of failure for intrinsically acceptable results is limited. The combination of this normal distribution probability approach with guard bands allows controlling ß or type-II-errors, i.e. the acceptance of intrinsically not conforming results is limited. Here, no assumptions concerning the manufacturing range are needed; therefore this approach can also be applied for quantitation of impurities. The guard band approach allows the highest level of control, but requires in turn high demands on the precision. Therefore, it should be restricted to drug product assays or impurity determinations with larger risks, i.e. justified by a corresponding clinical relevance, such as narrow therapeutic ranges or substantial toxicity.

Towards quality assessed characterization of nanomaterial: Transfer of validated protocols for size measurement by dynamic light scattering and evaluation of zeta potential by electrophoretic light scattering

Quality control analysis of nanomaterials has been identified as a major issue to pursue their development in different industrial fields including nanomedicine. One difficulty is the lack of standardized and validated protocols suitable to achieve their characterization. In a previous work, we have developed standardized protocols for the evaluation of the size and zeta potential of nanomaterials based on methods described in the ISO standard and have performed validation of each one. The present work was aimed to transfer these protocols in three independent receiving laboratories. No official guideline was described in the literature to achieve such a transfer. A comparative study for receiving laboratories equipped with the same instrument as the sending laboratory was designed based on the Code of Federal Regulation edited by the Food and Drug Administration. For the receiving laboratory equipped with an instrument working at a different wavelength, a new validation was designed and applied. Corresponding statistical methods were used for the analysis of the results. A successful transfer of the protocols in all receiving laboratories was achieved. All laboratories recorded consistent results applying in blind the protocol of size measurements on two samples of nanomaterials from which included one reference.

Reproducibility of the anti-Factor Xa and anti-Factor IIa assays applied to enoxaparin solution

Enoxaparin is a widely used subcutaneously administered antithrombotic agent comprising a complex mixture of glycosaminoglycan chains. Owing to this complexity, its antithrombotic potency cannot be defined by physicochemical methods and is therefore evaluated using an enzymatic assay of anti-Xa and anti-IIa activity. Maintaining consistent anti-Xa activity in the final medicinal product allows physicians to ensure administration of the appropriate dosage to their patients. Bioassays are usually complex and display poorer reproducibility than physicochemical tests such as HPLC assays. Here, we describe the implementation of a common robotic platform and standard release potency testing procedures for enoxaparin sodium injection (Lovenox, Sanofi, Paris, France) products at seven quality control sites within Sanofi. Qualification and analytical procedures, as well as data handling, were optimized and harmonized to improve assay reproducibility. An inter-laboratory study was performed in routine-release conditions. The coefficients of variation for repeatability and reproducibility in assessments of anti-Xa activity were 1.0% and 1.2%, respectively. The tolerance interval in reproducibility precision conditions, expressed as percentage potency, was 96.8-103.2% of the drug product target of 10,000 IU/ml, comparing favorably with the United States of America Pharmacopeia specification (90-110%). The maximum difference between assays in two different laboratories is expected to be 4.1%. The reproducibility characteristics of anti-IIa activity assessments were found to be similar. These results demonstrate the effectiveness of the standardization process established and allow for further improvements to quality control in Lovenox manufacture. This process guarantees closeness between actual and target potencies, as exemplified by the results of release assays obtained during a three-year period.