Development of quality-by-design analytical methods

A Novel Method for Development and Validation of the Degradation Products Analysis of N-Carbamylglutamate with UHPLC by Using Design of Experiment Approach

Carglumic acid, also known as N-carbamyl-l-glutamic acid, is a medication used in the treatment of a rare genetic disorder called N-acetylglutamate synthase (NAGS) deficiency. To the authors' knowledge, there was no method reported in the literature for the determination of degradation products suitable for quality control analyses of carglumic acid. Thus, the aim of the presented study is to develop an impurity method with a UHPLC/DAD detector configuration compatible with industrial standards from the European Pharmacopeia and the United States Pharmacopeia, making the drug more accessible for developing and underdeveloped countries through its precise evaluation. The method involved the separation of carglumic acid and its degradation products using a reverse-phase C18 column (Waters, BEH 150 mm × 2.1 mm, 1.7 μm) at a flow rate of 0.39 mL/min with a stop time of 10 min. To separate all unknown and known impurities, a gradient elution (phosphate buffer, pH 2.4, and acetonitrile) system was used. The detection was performed at 214 nm. Forced degradation studies were conducted under different stress conditions, including acidic, basic, oxidative, thermal, and photolytic stress. Placket-Burman statistical experimental design was used to demonstrate the robustness of this method, and the suitability of the method was confirmed under the applied conditions. Box-Behnken design was used to provide the optimum resolution between the peaks determined to be critical during the optimization. The developed method was validated according to ICH guidelines for specificity, linearity, accuracy, precision, and robustness. The limit of detection and limit of quantification were 0.7 and 0.15 μg/mL for carglumic acid, respectively.

Innovative Reversed-Phase Chromatography Platform Approach for the Fast and Accurate Characterization of Membrane Vesicles' Protein Patterns

Outer membrane vesicles (OMVs) have been widely explored to develop vaccine candidates for bacterial pathogens due to their ability to combine adjuvant properties with immunogenic activity. OMV expresses a variety of proteins and carbohydrate antigens on their surfaces. For this reason, there is an analytical need to thoroughly characterize the species expressed at their surface: we here present a simple and accurate reversed-phase ultrahigh-performance liquid chromatography (RP-UPLC) method developed according to quality by design principles. This work provides an analytical alternative to the classical sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) characterization. The higher selectivity and sensitivity of the RP-UHPLC assay allow for the identification of additional protein species with respect to SDS-PAGE and facilitate its precise relative abundance quantification. According to validation results, the assay showed high accuracy, linearity, precision, repeatability, and a limit of quantification of 1% for less abundant proteins. This performance paves the way for improved production campaign consistency while also being analytically simple (no sample pretreatment required), making it suitable for routine quality control testing. In addition, the applicability of the assay to a wider range of vesicle classes (GMMA) was demonstrated.

Discriminative Dissolution Method Development Through an aQbD Approach

Using a one-factor-at-a-time approach for dissolution method and discrimination analysis can be time-consuming and may not yield the optimal and discriminative method. To address this, we have developed a two-stage workflow for the dissolution method development followed by demonstration of discrimination power through an analytical Quality by Design (aQbD) approach. In the first stage, an optimal dissolution method was achieved by determining the method operable design region (MODR) through a design of experiment study of the high-risk method-related parameters. In the second stage, we established a Formulation-Discrimination Correlation Diagram strategy to examine the method discrimination capability, through which one can determine the method discriminative design region (MDDR) and visualize the impact of each formulation parameter and their interactions on dissolution. The application of aQbD principles into a workflow provides a scientific-driven guidance for robust method development and demonstrating discrimination power for dissolution methods.

Exploring novel and fast stability or sameness evaluation tool for different categories of injectable formulations

The establishment of drug product stability and sameness is the heart of generic formulation development. For regulatory filing, various instrumental methods are used on a case basis to establish the generic and innovator product sameness in multiple aspects. Here in the present study, we explored the applicability of the Time-correlated single photon counting (TCS-PC) technique as a fast, reliable, and nondestructive method for establishing the sameness of three different categories of injectable formulations, namely, Amphotericin B liposome for injection, enoxaparin injection, and iron sucrose injection. All three category formulations were evaluated in their native and artificially induced post degradation state to identify the discrimination power of the used instrumental techniques. The degradation of materials were confirmed by high performance liquid chromatography (HPLC). Based on the product category, pre and post-degradation samples were evaluated by selective instrumental methods like differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), fluorescence spectroscopy, particle size analysis by dynamic light scattering (DLS), small angle X-ray scattering (SAXS), Raman spectroscopy, inductively coupled plasma optical-emission spectrometry (ICP-OES) and circular dichroism study. All pre and post-degradation samples were further analyzed by TCS-PC. We observed that, TCS-PC can identify the differences between the initial and post degradation samples in very less time with promising discrimination power across the different injectable formulation types. Thus TCS-PC can be used as a fast and promising stability or sameness evaluation tool for different injectable drug products.

Exquisite integration of quality-by-design and green analytical approaches for simultaneous determination of xylometazoline and antazoline in eye drops and rabbit aqueous humor, application to stability study

This work implements a stability indicating HPLC method developed to simultaneously determine xylometazoline (XYLO) and antazoline (ANT) in their binary mixture, rabbit aqueous humor and cited drug's degradates by applying analytical quality-by-design (AQbD) combined with green analytical chemistry (GAC) experiment for the first time. This integration was designed to maximize efficiency and minimize environmental impacts, as well as energy and solvent consumption. Analytical quality-by-design was applied to achieve our aim starting with evaluation of quality risk and scouting analysis, tracked via five parameters chromatographic screening using Placket-Burman design namely: pH, temperature, organic solvent percentage, flow rate, and wavelength detection. Recognizing the critical method parameters was done followed by optimization employing central composite design and Derringer's desirability toward assess optimum conditions that attained best resolution with satisfactory peak symmetry with short run time. Optimal chromatographic separation was attained by means of an XBridge® C18 (4.6 × 250 mm, 5 µm) column through isocratic elution using a mobile phase consists of phosphate buffer (pH 3.0): ethanol (60:40, by volume) at a 1.6 mL/min flow rate and 230.0 nm UV detection. Linearity acquired over a concentration range of 1.0-100.0 µg/mL and 0.5-100.0 µg/mL for XYLO and ANT, respectively. Furthermore, imperiling cited drugs' stock solutions to stress various conditions and satisfactory peaks of degradation products were obtained indicating that cited drugs are vulnerable to oxidative degradation and basic hydrolysis. Degradates' structures were elucidated using mass spectrometry. Applying various assessment tools; namely: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI), Greenness method's evaluation was applied and proved to be green. In fact, the developed method is established to be perceptive, accurate, and selective to assess cited drugs for routine analysis.

The inversion of multiresponse partial least squares models, a useful tool to improve analytical methods in the framework of analytical quality by design

Analytical Quality by Design (AQbD) is the adaptation of Quality by Design (QbD) when it is applied to the development of an analytical method. The main idea is to develop the analytical method in such a way that the desired quality of the Critical Quality Attributes (CQAs), stated via the analytical target profile (ATP), is maintained while allowing some variation in the Control Method Parameters (CMPs). The paper presents a general procedure for selecting factor levels in the CMPs to achieve the desired responses, characterized by the CQAs, when liquid chromatographic methods are to be used for the simultaneous determination of several analytes. In such a case, the CMPs are usually the composition of the ternary mobile phase, its flow rate, column temperature, etc., while typical CQAs refer to the quality of the chromatograms in terms of the resolution between each pair of consecutive peaks, initial and final chromatographic time, etc. The analytical target profile in turn defines the desired characteristics for the CQAs, the reason for the whole approach. The procedure consists of four steps. The first is to construct a D-optimal combined design (mixture-process design) to select the domain and levels of the CMPs. The second step is to fit a PLS2 model to predict the analytical responses expressed in the ATP (the good characteristics of the chromatogram) as a function of the CMPs. The third step is the inversion of the PLS2 model to obtain the conditions necessary to obtain the preset ATP in the corresponding CQAs. The inversion is performed computationally in order to estimate the Pareto front of these responses, namely, a set of experimental conditions to perform the chromatographic determination for which the desired critical quality attributes are met. The fourth final step is to obtain the Method Operable Design Region (MODR), that is, the region where the CMPs can vary while maintaining the quality of the CQAs. The procedure has been applied to some cases involving different analytes, all of which are regulated by the European Union due to their toxicity to human health, namely five bisphenols and ten polycyclic aromatic hydrocarbons.

Drilling into "Quality by Design" Approach for Analytical Methods

The need for consistency in analytical method development reinforces the dependence of pharmaceutical product development and manufacturing on robust analytical data. The Analytical Quality by Design (AQbD), akin to the product Quality by Design (QbD) endows a high degree of confidence to the method quality developed. AQbD involves the definition of the analytical target profile as starting point, followed by the identification of critical method variables and critical analytical attributes, supported on risk assessment and design of experiment tools for the establishment of a method operable design region and control strategy of the method. This systematic approach moves away from reactive troubleshooting to proactive failure reduction. The objective of this review is to highlight the elements of the AQbD framework and provide an overview of their implementation status in various analytical methods used in the pharmaceutical field. These methodologies include but are not limited to, high-performance liquid chromatography, UV-Vis spectrophotometry, capillary electrophoresis, supercritical fluid chromatography, and high-performance thin-layer chromatography. Finally, a critical appraisal is provided to highlight how regulators have encouraged AQbD principles application to boost the prevention of method failures and a better understanding of the method operable design region (MODR) and control strategy, ultimately resulting in cost-effectiveness and regulatory flexibility.

Preformulation and Long-Term Stability Studies of an Optimized Palatable Praziquantel Ethanol-Free Solution for Pediatric Delivery

To date, the treatment for cysticercosis and neurocysticercosis consists of a single oral intake of praziquantel (5-10 mg/kg), which since it is only available as tablets, hinders its administration to pediatric patients. Praziquantel is a poorly water-soluble drug which represents a challenge for its formulation in solution, particularly for the pediatric population. Thus, this study aimed to develop a palatable solution for praziquantel using pharmaceutical-accepted co-solvent systems. A design of experiments approach was applied to identify the optimal conditions for achieving a suitable amount of praziquantel in solution using co-solvent mixtures. Thus, praziquantel solubility increased from 0.38 up to 43.50 mg/mL in the optimized system. A taste masking assay in healthy human volunteers confirmed a successful reduction of drug bitterness after the addition of selected flavors and a sweetener. Stability studies were also conducted at different temperatures (4, 25, and 40 °C) for 12 months Even though the presence of the three known impurities of praziquantel was observed, their amounts never exceeded the acceptance criteria of the USP. Thus, this novel approach should be considered a valuable alternative for further preclinical studies considering the high prevalence of this infection worldwide.

Analytical Quality by Design-Compliant Development of a Cyclodextrin-Modified Micellar ElectroKinetic Chromatography Method for the Determination of Trimecaine and Its Impurities

In 2022, the International Council for Harmonisation released draft guidelines Q2(R2) and Q14, intending to specify the development and validation activities that should be carried out during the lifespan of an analytical technique addressed to assess the quality of medicinal products. In the present study, these recommendations were implemented in Capillary Electrophoresis method development for the quality control of a drug product containing trimecaine, by applying Analytical Quality by Design. According to the Analytical Target Profile, the procedure should be able to simultaneously quantify trimecaine and its four impurities, with specified analytical performances. The selected operative mode was Micellar ElectroKinetic Chromatography employing sodium dodecyl sulfate micelles supplemented with dimethyl-β-cyclodextrin, in a phosphate-borate buffer. The Knowledge Space was investigated through a screening matrix encompassing the composition of the background electrolyte and the instrumental settings. The Critical Method Attributes were identified as analysis time, efficiency, and critical resolution values. Response Surface Methodology and Monte Carlo Simulations allowed the definition of the Method Operable Design Region: 21-26 mM phosphate-borate buffer pH 9.50-9.77; 65.0 mM sodium dodecyl sulfate; 0.25-1.29% v/v n-butanol; 21-26 mM dimethyl-β-cyclodextrin; temperature, 22 °C; voltage, 23-29 kV. The method was validated and applied to ampoules drug products.

Analysis of Fixed-Dose Combination of Three Antihypertensive Drugs by a Green and Quality by Design Approach

This paper presents the result of a combined employment of Analytical Quality-by-Design and Green Analytical Chemistry principles for the development of a robust high-performance liquid chromatography method for simultaneous determination of fixed-dose combination of three drugs, perindopril tert-butylamine, amlodipine besylate and indapamide. Optimum conditions were achieved on ZORBAX Eclipse XDB-C18 column (150 mm × 4.6 mm, 5 μm particle size), the mobile phase comprising acetonitrile and phosphate buffer (30 mM, pH 2.7) in the ratio 34:66 (v/v), the flow rate of 1 mL min-1, injection volume of 10 μL and UV detection at 210 nm. By assigning the design space from the overlay plot, the regions within which the robustness of the method is achieved were defined and confirmed by Dong's algorithm calculations. The proposed method was validated and shown to be applicable for the determination of the three drugs in commercially available tablets. In addition, the impact of the method on the environment was assessed through four different analytical tools: National Environmental Methods Index, Analytical Eco-Scale, Green Analytical Procedure Index and Assessment of Green Profile. The proposed method was determined to be greener, with minimal impact on the environment with regard to waste production, energy consumption and use of hazardous chemicals.

Developing an improved UHPLC method for impurity profile analysis of ceftriaxone using analytical quality by design

In this study, we developed a new reversed-phase ultra-high-performance liquid chromatography (UHPLC) method for comprehensively measuring impurities in ceftriaxone. The method was developed based on the Chinese Pharmacopoeia (ChP) HPLC method, which is limited by the lack of selectivity to potential impurities and a long running time. Screening experiments showed that octylamine concentration, mobile phase pH, and organic phase ratio were critical method parameters. Further optimisation and Monte-Carlo simulations were performed to map out the design space. The selected working conditions resulted in a complete separation of the impurity profile in approximately 10 min. A multivariate approach confirmed that the method was robust, and the proportion of acetonitrile should be carefully controlled. Additionally, the developed UHPLC method could be transferred back to HPLC in a single step using a Columns Calculator, providing a new approach for the rapid and effective development of the HPLC method. Our findings could serve as a reference for developing the next version of the ChP.

Analytical quality by design-based RP-HPLC method for quantification of pioglitazone and candesartan cilexetil in bilayer tablet and its forced degradation studies

Aim: The current project involves developing an RP-HPLC method for simultaneous quantification of Candesartan Cilexetil and Pioglitazone based on analytical quality by design (AQbD).

Materials and methods: When analysed in the Design Expert application, the critical method parameters were systematically refined using Central Composite Design and contours were derived for significant variables. A contour plot has been used to discover the technique operable design region that governs response variation, which is then empirically tested.

Results: Successful chromatographic separation of title analytes was achieved on kromasil C18 (150 × 4.6 mm, 5 µm) column at 30 °C with mobile phase comprising 60% 20 Mm Potassium dihydrogen orthophosphate and 40% acetonitrile (v/v), isocratic elution pattern, 0.9 mL/min flow rate, and UV detection at 220 nm. The linear model for Candesartan Cilexetil was from 4 to 24 µg/ mL and Pioglitazone at 7.5–45 µg/ mL, respectively.

Conclusion: The method met all the ICH Q2 (R1) validation criteria. The current approach aided for analysing simultaneous drugs can be expanded into quantifying drugs in biological matrix predominance with maximum recovery.

Development of a Quantitative Chromatographic Fingerprint Analysis Method for Sugar Components of Xiaochaihu Capsules Based on Quality by Design Concept

Background: Xiaochaihu capsule is composed of seven traditional Chinese medicines. The pharmacopoeia only focuses on the quantitative detection of baicalin, which cannot fully reflect the quality of the preparation. Some medium polar components were used to establish the fingerprint of Xiaochaihu capsule, but there was no report on the strong polar components. Methods: A high performance liquid chromatography-corona charged aerosol detection technology was used to establish a fingerprint analysis method for Xiaochaihu capsules following an analytical quality by design approach. Definitive screening designed experiments were used to optimize the method parameters. A stepwise regression method was used to build quantitative models. The method operable design region was calculated using the experimental error simulation method. Plackett–Burman designed experiments were carried out to test robustness. Results: The contents of four components were simultaneously determined. There were seven common peaks in the fingerprint. The common peak area accounted for 91.72%. Both fingerprint and quantitative analysis methods were validated as applicable in the methodology study. The quantitative fingerprint analysis method for sugar components can fill the gap in the detection of strong polar components in the existing methods. It provides a new technology for the comprehensive overall evaluation of Xiaochaihu capsule.

Development of an ELISA Assay for the Determination of SARS-CoV-2 Protein Subunit Vaccine Antigen Content

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) protein subunit vaccine is one of the mainstream technology platforms for the development of COVID-19 vaccines, and most R&D units use the receptor-binding domain (RBD) or spike (S) protein as the main target antigen. The complexity of vaccine design, sequence, and expression systems makes it urgent to establish common antigen assays to facilitate vaccine development. In this study, we report the development of a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) to determine the antigen content of SARS-CoV-2 protein subunit vaccines based on the United States Pharmacopeia <1220> and ICH (international conference on harmonization) Q14 and Q2 (R2) requirements. A monoclonal antibody (mAb), 20D8, was identified as the detection antibody based on its high RBD binding activity (EC50 = 8.4 ng/mL), broad-spectrum anti-variant neutralizing activity (EC50: 2.7−9.8 ng/mL for pseudovirus and EC50: 9.6−127 ng/mL for authentic virus), good in vivo protection, and a recognized linear RBD epitope (369−379 aa). A porcine anti-RBD polyclonal antibody was selected as the coating antibody. Assay performance met the requirements of the analytical target profile with an accuracy and precision of ≥90% and adequate specificity. Within the specification range of 70−143%, the method capability index was >0.96; the misjudgment probability was <0.39%. The method successfully detected SARS-CoV-2 protein subunit vaccine antigens (RBD or S protein sequences in Alpha, Beta, Gamma, or Delta variants) obtained from five different manufacturers. Thus, we present a new robust, reliable, and general method for measuring the antigenic content of SARS-CoV-2 protein subunit vaccines. In addition to currently marketed and emergency vaccines, it is suitable for vaccines in development containing antigens derived from pre-Omicron mutant strains.

Expanding Quality by Design Principles to Support 3D Printed Medical Device Development Following the Renewed Regulatory Framework in Europe

The vast scope of 3D printing has ignited the production of tailored medical device (MD) development and catalyzed a paradigm shift in the health-care industry, particularly following the COVID pandemic. This review aims to provide an update on the current progress and emerging opportunities for additive manufacturing following the introduction of the new medical device regulation (MDR) within the EU. The advent of early-phase implementation of the Quality by Design (QbD) quality management framework in MD development is a focal point. The application of a regulatory supported QbD concept will ensure successful MD development, as well as pointing out the current challenges of 3D bioprinting. Utilizing a QbD scientific and risk-management approach ensures the acceleration of MD development in a more targeted way by building in all stakeholders' expectations, namely those of the patients, the biomedical industry, and regulatory bodies.

Analytical Quality by Design (AQbD) Approach to the Development of Analytical Procedures for Medicinal Plants

Scientific regulatory systems with suitable analytical methods for monitoring quality, safety, and efficacy are essential in medicinal plant drug discovery. There have been only few attempts to adopt the analytical quality by design (AQbD) strategy in medicinal plants analysis over the last few years. AQbD is a holistic method and development approach that understands analytical procedure, from risk assessment to lifecycle management. The enhanced AQbD approach reduces the time and effort necessary to develop reliable analytical methods, leads to flexible change control through the method operable design region (MODR), and lowers the out-of-specification (OOS) results. However, it is difficult to follow all the AQbD workflow steps in the field of medicinal plants analysis, such as defining the analytical target profiles (ATPs), identifying critical analytical procedure parameters (CAPPs), among others, because the complexity of chemical and biological properties in medicinal plants acts as a barrier. In this review, various applications of AQbD to medicinal plant analytical procedures are discussed. Unlike the analysis of a single compound, medicinal plant analysis is characterized by analyzing multiple components contained in biological materials, so it will be summarized by focusing on the following points: Analytical methods showing correlations within analysis parameters for the specific medicinal plant analysis, plant raw material diversity, one or more analysis targets defined for multiple phytochemicals, key analysis attributes, and analysis control strategies. In addition, the opportunities available through the use of design-based quality management techniques and the challenges that coexist are also discussed.

New Trends in the Quality Control of Enantiomeric Drugs: Quality by Design-Compliant Development of Chiral Capillary Electrophoresis Methods

Capillary electrophoresis (CE) is a potent method for analyzing chiral substances and is commonly used in the enantioseparation and chiral purity control of pharmaceuticals from different matrices. The adoption of Quality by Design (QbD) concepts in analytical method development, optimization and validation is a widespread trend observed in various analytical approaches including chiral CE. The application of Analytical QbD (AQbD) leads to the development of analytical methods based on sound science combined with risk management, and to a well understood process clarifying the influence of method parameters on the analytical output. The Design of Experiments (DoE) method employing chemometric tools is an essential part of QbD-based method development, allowing for the simultaneous evaluation of experimental parameters as well as their interaction. In 2022 the International Council for Harmonization (ICH) released two draft guidelines (ICH Q14 and ICH Q2(R2)) that are intended to encourage more robust analytical procedures. The ICH Q14 guideline intends to harmonize the scientific approaches for analytical procedures' development, while the Q2(R2) document covers the validation principles for the use of analytical procedures including the recent applications that require multivariate statistical analyses. The aim of this review is to provide an overview of the new prospects for chiral CE method development applied for the enantiomeric purity control of pharmaceuticals using AQbD principles. The review also provides an overview of recent research (2012-2022) on the applicability of CE methods in chiral drug impurity profiling.

Implementation of QbD Approach to the Development of Chromatographic Methods for the Determination of Complete Impurity Profile of Substance on the Preclinical and Clinical Step of Drug Discovery Studies

The purpose of this work was to demonstrate the use of the AQbD with the DOE approach to the methodical step-by-step development of a UHPLC method for the quantitative determination of the impurity profile of new CPL409116 substance (JAK/ROCK inhibitor) on the preclinical and clinical step of drug discovery studies. The critical method parameters (CMPs) have been tested extensively: the kind of stationary phase (8 different columns), pH of the aqueous mobile phase (2.6, 3.2, 4.0, 6.8), and start (20–25%) and stop (85–90%) percentage of organic mobile phase (ACN). The critical method attributes (CMAs) are the resolution between the peaks (≥2.0) and peak symmetry of analytes (≥0.8 and ≤1.8). In the screening step, the effects of different levels of CMPs on the CMAs were evaluated based on a full fractional design 22. The robustness tests were established from the knowledge space of the screening step and performed by application fractional factorial design 2(4−1). Method operable design region (MODR) was generated. The probability of meeting the specifications for the CMAs was calculated by Monte-Carlo simulations. In relation to literature such a complete AQbD approach including screening, optimization, and validation steps for the development of a new method for the quantitative determination of the full profile of nine impurities of an innovative pharmaceutical substance with the structure-based pre-development pointed out the novelty of our work. The final working conditions were as follows: column Zorbax Eclipse Plus C18, aqueous mobile phase 10 mM ± 1 mM aqueous solution of HCOOH, pH 2.6, 20% ± 1% of ACN at the start and 85% ± 1% of ACN at the end of the gradient, and column temperature 30 °C ± 2 °C. The method was validated in compliance with ICH guideline Q2(R1). The optimized method is specified, linear, precise, and robust. LOQ is on the reporting threshold level of 0.05% and LOD at 0.02% for all impurities.

Analytical quality by design-compliant retention modeling for exploring column interchangeabilities in separating ezetimibe and its related substances

There are several potential advantages of using experimental design-based retention modeling for chromatographic method development. Most importantly, through the model-delivered systematic understanding (Design Spaces), users can benefit from increased method consistency, flexibility and robustness that can efficiently be achieved at lesser amount of development time. As a result, modeling tools have always been great supplementary assets and welcomed by both the pharmaceutical industry and the regulatory authorities. Most recently published chapters of ICH however - Q2(R2) and Q14 (both currently drafts) - evidence a further paradigm shift, specifying the elements of model-based development strategies in the so-called "enhanced approach". The main aim of this study was to investigate the impact of stationary phase chemistries on chromatographic method performance in the application example of ezetimibe and its related substances. A commercial modeling software package (DryLab®) was used to outline three-dimensional experimental design frameworks and acquire model Design Spaces (DSs) of 9 tested columns. This was done by performing 12 input calibration experiments per column, systematically changing critical method parameters (CMPs) as variables such as the gradient time (tG), temperature (T) and the ternary composition (tC) of the mobile phase. The constructed models allowed studying retention behaviors of selected analytes within each separation systems. In the first part of our work, we performed single optimizations for all nine stationary phases with substantially different surface modifications based on their highest achievable critical resolution values. For these optimum points in silico robustness testing was performed, clearly showing a change of CMPs, depending on the column, and specified optimum setpoint. In the second part of our work, we simultaneously compared the three-dimensional virtual separation models to identify all method parameter combinations that could provide at least baseline separation (R_{s, crit.}>1.50). These overlapping areas between the models described a common method operational design region (MODR) where columns were considered completely interchangeable - in terms of their baseline resolving capability - regardless of their exact physicochemical properties. A final optimized, column-independent working point within the common MODR was selected for verification. Indeed, experimental chromatograms showed excellent agreement with the model; all columns in the common condition were able to yield critical resolution values higher than 2.0, only their retentivity (elution window of peaks) was found different in some cases. Our results underline that a profound understanding of the separation process is of utmost importance andthat in some cases, adequate selectivity is achievable on various stationary phases.

Quality by Design: A Suitable Methodology in Industrial Pharmacy for Costa Rican Universities

This review aims to present the Quality by Design (QbD) model as a suitable methodology to perform research in the academic Costa Rican institutions that teach Pharmacy. Pubmed, Science Direct, and Google Scholar databases were screened for original research papers and review papers published not more than ten years ago. Institutional repositories from the different universities were reviewed as well. The QbD model stands out as a great methodology for carrying out research projects regarding Pharmaceutical Sciences, but especially for Industrial Pharmacy, where it has contributed in terms of formulation development, manufacturing, and quality control. Academic research based on this model enables the training and development of practical, scientific, and leadership skills in Industrial Pharmacy students. The generated knowledge can be shared in classrooms, which represents an ideal environment to communicate research results and to foster collaborative work between researchers, professors, and students. Moreover, research performed through a QbD approach increases the confidence shown by the industrial sector and health regulatory authorities in the quality of the research, products, and knowledge that are developed and created in an Academy. As a result, the implementation of the model has allowed the creation, transfer, and materialization of knowledge from the Costa Rican Academy to different local pharmaceutical industries.

Quality-by-Design Principles Applied to the Establishment of a Pharmaceutical Quality Control Laboratory in a Resource-Limited Setting: The Lab Water

Quality-by-design (QbD) is defined as a systematic approach to design and develop a product/service based on sound science and quality risk management. It is already frequently applied in the pharmaceutical industry mainly in the development of pharmaceutical products and analytical methods but is not well established in the setup of facilities like quality control (QC) laboratory (lab). Therefore, lab QbD (lQbD) concept is introduced considering lab water purification system as an example. The water purification system comprising distillation unit coupled with Nanopure Analytical Ultrapure Water System combined with a 0.2-micron filter was established in Jimma University Laboratory of Drug Quality (JuLaDQ). The consistent capability of the established water purification system was evaluated through routine monitoring of the critical quality parameters (i.e., physicochemical, HPLC-DAD chromatogram total peak area, and resistivity) of freshly prepared lab water for a period of one year. In addition, quality of different grade water (tap water, distilled water (before and/or after cleaning distillation unit), and fresh ultrapure water (18.2 MΩ × cm at 25°C)) used in JuLaDQ was evaluated. The results of routine analysis of water quality revealed that HPLC global peak area at 210 and 254 nm could serve as one of the discriminatory control strategies to evaluate the capability of water purification system to produce the desired quality of lab water; and thus, we proposed a specification limit of 5,000 mAU∗s and 5,500 mAU∗s for global peak area at 254 and 210 nm, respectively, as system suitability parameter.

Development of an Analytical Method for Determination of Related Substances and Degradation Products of Cabotegravir Using Analytical Quality by Design Principles

Cabotegravir is one of the newly approved human immunodeficiency virus (HIV) integrase enzyme inhibitors used for the prevention and treatment of HIV infection. It is the first approved long-acting injectable antiretroviral therapy for HIV and is also very effective in combination with rilpivirine, a non-nucleoside reverse transcriptase inhibitor. Therefore, future drug development involving cabotegravir can be expected. We developed an ultrahigh performance liquid chromatography (UHPLC) method compatible with mass spectrometry for the determination of eight cabotegravir impurities. The described method is able to differentiate cabotegravir and its related substances as well as its degradation products. Analytical quality by design principles were used for method development. The method is robust within the defined method operable design region: flow rate = 0.32-0.40 mL/min; column temperature = 30-40 °C; pH of mobile phase A = 3.25-3.75, and the final percent of acetonitrile in gradient = 50.0-60.0%. Inside the method operable design region, a working optimal point was selected: pump flow rate = 0.36 mL/min; column temperature = 35 °C; pH of mobile phase A = 3.5, and final percent of acetonitrile in gradient = 55%. Method validation was performed, and the following parameters were verified: accuracy, repeatability, linearity, response factors, detection limit, and quantification limit. All method validation results were within selected criteria. The presented method could be used for the development of new pharmaceutical products based on cabotegravir.

Assessment of greenness for the determination of voriconazole in reported analytical methods

Analytical research with adverse environmental impact has caused a severe rise in concern about the ecological consequences of its strategies, most notably the use and emission of harmful solvents/reagents into the atmosphere. Nowadays, industries are searching for the best reproducible methods. Voriconazole is a second-generation azole derivative used effectively in the treatment of Candida and Aspergillus species infections and oropharyngeal candidiasis in AIDS patients. Recently it has become the drug of choice in treating mucormycosis in several countries, which raises the need for production in large quantities. The present review deals with various recent important analytical techniques used to estimate voriconazole and its combination in pharmaceutical formulations and biological fluids. The methods show their own unique way of analyzing voriconazole in different matrices with excellent linearity, detection, and quantification limits. Additionally, this article deals with methods and solvents analyzed for their impact on the environment. This is followed by estimating the degree of greenness of the methods using various available assessment tools like analytical eco-scale, national environmental method index, green analytical procedure index, and AGREE metrics to confirm the environmental impact. The scores obtained with the evaluation tools depict the quantum of greenness for the reported methods and provide an ideal approach adopted for VOR estimation. Very few methods are eco-friendly, which shows that there is a need for the budding analyst to develop methods based on green analytical principles to protect the environment.

Selection of Analytical Technology and Development of Analytical Procedures Using the Analytical Target Profile

A structured approach to method development can help to ensure an analytical procedure is robust across the lifecycle of its use. The analytical target profile (ATP), which describes the required quality of the reportable value to be produced by the analytical procedure, enables the analytical scientist to select the best analytical technology on which to develop their procedure(s). Once the technology has been identified, screening of potentially fit for purpose analytical procedures should take place. Analytical procedures that have been demonstrated to meet the ATP should be evaluated against business drivers (e.g., operational constraints) to determine the most suitable analytical procedure. Three case studies are covered from across small molecules, vaccines, and biotherapeutics. The case studies cover different aspects of the analytical procedure selection process, such as the use of platform method development processes and procedures, the development of multiattribute analytical procedures, and the use of analytical technologies to provide product characterization knowledge in order to define or redefine the ATP. Challenges associated with method selection are discussed such as where existing pharmacopoeial monographs link acceptance criteria to specific types of analytical technology.

Quality-by-design in pharmaceutical development: From current perspectives to practical applications

Current pharmaceutical research directions tend to follow a systematic approach in the field of applied research and development. The concept of quality-by-design (QbD) has been the focus of the current progress of pharmaceutical sciences. It is based on, but not limited, to risk assessment, design of experiments and other computational methods and process analytical technology. These tools offer a well-organized methodology, both to identify and analyse the hazards that should be handled as critical, and are therefore applicable in the control strategy. Once implemented, the QbD approach will augment the comprehension of experts concerning the developed analytical technique or manufacturing process. The main activities are oriented towards the identification of the quality target product profiles, along with the critical quality attributes, the risk management of these and their analysis through in silico aided methods. This review aims to offer an overview of the current standpoints and general applications of QbD methods in pharmaceutical development.

Validated Modernized Assay for Foscarnet in Pharmaceutical Formulations Using Suppressed Ion Chromatography Developed through a Quality by Design Approach

Inspired by the United States Pharmacopoeia (USP) “monograph modernization” initiative, we developed and validated an assay for foscarnet sodium injection solution (“foscavir”), following quality by design (QbD) principles, incorporating design of experiments (DoE) and multivariate data analysis to establish the design space and robust setpoint of the method. The resulting analytical procedure was based on ion chromatography (IC) with suppressed conductivity detection, employing an isocratic carbonate–bicarbonate eluent system. The assay was successfully validated at the robust setpoint conditions, according to the guidelines established by the International Council for Harmonization (ICH). The linear range stretched at least from 5 to 100 mg/L with high repeatability (relative standard deviation, RSD ≤ 0.3%) both at the target concentration (60 mg/L) and at 50% and 150% from this level. Special attention was given to establish a rugged assay that would be easily transferable between laboratories, and the recorded recoveries of 98.2–100.5% for both the formulated drug product and the drug substance during intermediate precision evaluation at different analysis situations indicated that this mission was accomplished. A multivariate assessment of intermediate precision data acquired using an experimental design scheme revealed that the assay was not adversely affected by any of the situation variables, including the use of different liquid chromatography instrument types, regardless of if they were constructed from inert materials or stainless steel that had been passivated, even though such problems have been reported in several previous methods for analysis of foscarnet.

Quantification of Scopoletin from the Roots of Argyreia Speciosa (Linn. F) Sweet Using HPLC Through the Concept of Design of Experiment

BACKGROUND

The roots of Argyreia speciosa (Linn. F) Sweet (family: Convolvulaceae) are used in Ayurveda to treat male reproductive and nervous system disorders.

OBJECTIVE

Isolation of scopoletin from the roots of Argyreia speciosa, and development and validation of an analytical method using HPLC for the quantification of scopoletin from the root powder of Argyreia speciosa.

METHOD

Scopoletin was isolated from chloroform fraction prepared from hydrolyzed methanolic extract and identified using spectral studies. A reverse-phase HPLC-based analytical method was developed and optimized using the Design of Experiment (DoE) approach to estimate scopoletin from the roots of Argyreia speciosa. Scopoletin was separated and quantified using HPLC containing the C18 column and a PDA detector. The optimized mobile phase was methanol: water (pH∼3.2) [25: 75, %v/v].

RESULTS

The Box-Behnken design was used to optimize chromatographic parameters and the extraction procedure. The validation studies showed a linear relationship (r2=0.998) in the range of 1-40 µg/mL. The LOD and LOQ were found to be 0.28 µg/mL and 0.84 µg/mL, respectively, and the recovery values were found to be between 91.94 and 97.86%. The developed analytical method was found to be robust as well. The amount of scopoletin was estimated to be 0.024 ± 0.0016%w/w from dried root powder.

CONCLUSION

The recorded chromatogram and amount of scopoletin determined would serve as one of the standardization parameters to access the quality of raw material containing Argyreia speciosa.

HIGHLIGHTS

Developed analytical method may be adopted as a part of the standardization procedure for Argyreia speciosa in the quality control laboratory.

Application of Experimental Design Methodologies in the Enantioseparation of Pharmaceuticals by Capillary Electrophoresis: A Review

Chirality is one of the major issues in pharmaceutical research and industry. Capillary electrophoresis (CE) is an interesting alternative to the more frequently used chromatographic techniques in the enantioseparation of pharmaceuticals, and is used for the determination of enantiomeric ratio, enantiomeric purity, and in pharmacokinetic studies. Traditionally, optimization of CE methods is performed using a univariate one factor at a time (OFAT) approach; however, this strategy does not allow for the evaluation of interactions between experimental factors, which may result in ineffective method development and optimization. In the last two decades, Design of Experiments (DoE) has been frequently employed to better understand the multidimensional effects and interactions of the input factors on the output responses of analytical CE methods. DoE can be divided into two types: screening and optimization designs. Furthermore, using Quality by Design (QbD) methodology to develop CE-based enantioselective techniques is becoming increasingly popular. The review presents the current use of DoE methodologies in CE-based enantioresolution method development and provides an overview of DoE applications in the optimization and validation of CE enantioselective procedures in the last 25 years. Moreover, a critical perspective on how different DoE strategies can aid in the optimization of enantioseparation procedures is presented.

Developing a Validated HPLC Method for Quantification of Ceftazidime Employing Analytical Quality by Design and Monte Carlo Simulations

BACKGROUND

Ceftazidime, a third-generation cephalosporin, is widely used in the treatment of lung infections, often given as "off-label" nebulization. There is a need to develop a sensitive and robust analytical method to compute aerodynamic properties of ceftazidime following nebulization.

OBJECTIVE

The current study entails development of a simple, accurate, and sensitive HPLC method for ceftazidime estimation, employing the principles of analytical quality-by-design (AQbD) and Monte Carlo simulations.

METHOD

Selection of critical material attributes (CMAs) affecting method performance was accomplished by factor screening exercises. Subsequently, the influential CMAs, i.e., mobile phase ratio and flow rate, were systemically optimized using a face-centered cubic design for the chosen critical analytical attributes (CAAs). The factor relationship(s) between CMAs and CAAs was explored employing a 3 D-response surface and 2 D-contour plots, followed by numerical as well as graphical optimization, for establishing the optimal chromatographic conditions. The obtained method operable design region was validated by Monte Carlo simulations for defect rate analysis.

RESULTS

The optimized HPLC conditions for estimating ceftazidime were acetonitrile to acetic acid solution (75:25) as mobile phase at a flow rate of 0.7 mL/min, leading to Rt of 4.5 min and peak tailing ≤2. Validation studies, as per International Conference on Harmonization Q2(R1) guidance, demonstrated high sensitivity, accuracy, and efficiency of the developed analytical method with an LOD of 0.075 and LOQ of 0.227 µg/mL. Application of this chromatographic method was extrapolated for determining aerodynamic performance by nebulizing ceftazidime at a flow rate of 15 L/min using a next-generation impactor. The study indicated superior performance, sensitivity, and specificity of the developed analytical system for quantifying ceftazidime.

CONCLUSIONS

Application of an AQbD approach, coupled with Monte Carlo simulations, aided in developing a robust HPLC method for estimationof ceftazidime per se and on various stages of impactor.

HIGHLIGHTS

(i) QbD-enabled development of robust RP-HPLC method for ceftazidime quantification, (ii) Analytical method optimization employing Risk Assessment and Design of Experiments, (iii) Design space verification and defect rate analysis using Monte Carlo simulations, (iv) Chromatographic method validation as per ICH Q2 R1 guidelines and (v) Quantitative estimation of ceftazidime on various stages of impactor.

Analytical Method Lifecycle Management in Pharmaceutical Industry: a Review

The adoption of Quality by Design (QbD) and Analytical Method Lifecycle Management (AMLM) concepts to ensure the quality of pharmaceutical products has been applied and proposed over the last few years. These concepts are based on knowledge gained from the application of scientific and quality risk management approaches, throughout method lifecycle to assure continuous improvement and high reliability of analytical results. The overall AMLM starts with the definition of the method's intended use through the Analytical Target Profile definition, including three stages: (1) Method Design, taking advantage of the well-known concept of QbD; (2) Method Performance Qualification; (3) Continued Method Performance Verification. This is intended to holistically align method variability with product requirements, increasing confidence in the data generated, a regulatory requirement that the pharmaceutical industry must follow. This approach views all method-related activities, such as development, validation, transfer, and routine use as a continuum and interrelated process, where knowledge and risk management are the key enablers. An increase in method robustness, cost reduction, and decreased risk failures are some of the intrinsic benefits from this lifecycle management. This approach is clearly acknowledged both by regulators and industry. The roadmap of the regulatory and industry events that mark the evolution of these concepts helps to capture the current and future expectation of the pharmaceutical framework.

Direct distinction of ibuprofen and flurbiprofen enantiomers by ion mobility mass spectrometry of their ternary complexes with metal cations and cyclodextrins in the gas phase

Enantiomeric drugs are widely used and play important roles in pharmaceuticals. Ion mobility spectrometry coupled with mass spectrometry technology provides a unique method for distinguishing the enantiomeric drugs, enantiomeric identification, and quantitation in the gas phase. In this study, enantiomeric molecules of ibuprofen and flurbiprofen were clearly recognized by forming host-guest complex ions using trapped ion mobility time-of-flight mass spectrometry. Ternary complex ions can be produced easily by electrospray ionization of the mixed solutions of ibuprofen, cyclodextrins, and CaCl₂ , LiCl, or NaCl, as well as flurbiprofen, cyclodextrins, and CaCl₂ . The relative contents of different chiral ibuprofens in a mixed solution were also quantitatively measured. This new method is a simple, effective, and a convenient enantioselective analysis method.

In depth investigation of the retention behavior of structurally related β-blockers on RP-HPLC column: Quality by design and quantitative structure-property relationship complementary approaches for optimization and validation

The persistent introduction of new β-blockers motivates the demand for optimizing RP-HPLC well-designed analytical procedures that could be applied to this structurally related and commonly prescribed pharmacological group in order to reduce time and chemicals consumption in quality control units. Betoxolol HCl (BEX) and Carvidolol (CAR) were selected as representative examples to conduct predictive studies based on two complementary approaches, Quality by design (QBD) and Quantitative structure property relationship (QSPR). In concern QBD, a Box-Behnken design was adopted at variable chromatographic parameters to achieve the most proper conditions that might be applied for efficient analysis of the majority of group members. On the other hand, the retention time was chosen as the target property in the QSPR study that was conducted onto seven β. blockers (the two investigated drugs in addition to five other β. blockers) to find the best correlated molecular descriptors to the retention behavior. Both external and internal validation studies have comparable quality with training levels. Hence a simple selection algorithm of conventional features provides robust confirmatory predictive QBD and QSPR models. Derringer's desirability function as as a multi-criteria approach was applied for getting the optimum chromatographic analysis conditions. Efficient analysis of BET and CAR was achieved at column temperatures of 26.00 and 27.50 °C, respectively using acetonitrile and phosphate buffer (pH 4.55) 70:30 v/v as a mobile phase with a flow rate of 1.00 mL/min, and UV detection at 220 nm. The method was validated in accordance to ICH guidelines, and had exhibited acceptable precision, accuracy, linearity, and robustness.

Development and statistical optimization of alginate-Neusilin US2 micro-composite beads to elicit gastric stability and sustained action of hesperidin

The Alginate-Neusilin US2 micro-composite (MC) beads were fabricated and optimized for oral delivery of hesperidin (HES). A 32 full factorial design encompassing independent variables (factors) such as the concentration of sodium alginate (X1), and Neusilin US2 (X2) and dependant variables (response) such as particle size (Y1), entrapment efficiency (Y2), and swelling degree (Y3). Nine batches were prepared by formulation design employing statistical software JMP 13.2.1. The multiple regression analysis (MLRA) was carried to explore the influence of factor over responses. Further, a prediction profiler was used to trace the optimum concentration of factors based on desirable responses. The optimized beads (OF) were characterized for their morphology and size by motic microscopy and scanning electron microscopy. In vitro release, kinetic studies were performed in simulated gastric and intestinal fluids. In vivo pharmacokinetic studies revealed better absorption of HES from optimized beads (OF) compared to HES suspension which could be due to the prevention of acidic degradation of HES in the stomach. The estimated shelf life of OF formulation was found to be 3.86 years suggested better stability after fabrication. In a nutshell, the developed micro-composite beads of HES could be a better alternative for promising oral sustained delivery of HES.

Method Optimisation in Hydrophilic-Interaction Liquid Chromatography by Design of Experiments Combined with Quantitative Structure–Retention Relationships

Accurate prediction of the separation conditions for a set of target analytes with no retention data available is fundamental for routine analytical assays but remains a very challenging task. In this paper, a quality by design (QbD) optimisation workflow capable of discovering the optimal chromatographic conditions for separation of new compounds in hydrophilic-interaction liquid chromatography (HILIC) is introduced. This workflow features the application of quantitative structure−retention relationship (QSRR) methodology in conjunction with design of experiments (DoE) principles and was used to carry out a two-level full factorial DoE optimisation for a mixture of pharmaceutical analytes on zwitterionic, amide, amine, and bare silica HILIC stationary phases, with mobile phases containing varying acetonitrile content, mobile phase pH, and salt concentration. A dual-filtering approach that considers both retention time (tR) and structural similarity was used to identify the optimal set of analytes to train the QSRR in order to maximise prediction accuracy. Highly predictive retention models (average R2 of 0.98) were obtained and statistical analysis of the prediction performance of the QSRR models demonstrated their ability to predict the retention times of new compounds based solely on their molecular structures, with root-mean-square errors of prediction in the range 7.6–11.0 %. Further, the obtained retention data for pharmaceutical test compounds were used to compute their separation selectivity, which was used as input into a DoE optimiser in order to select the optimal separation conditions. Experimental separations performed under the chosen optimal working conditions showed good agreement with the theoretical predictions. To the best of our knowledge, this is the first study of a QbD optimisation workflow assisted with dual-filtering-based retention modelling to facilitate the method development process in HILIC.

Experimental design in HPLC separation of pharmaceuticals

Design of Experiments (DoE) is an indispensable tool in contemporary drug analysis as it simultaneously balances a number of chromatographic parameters to ensure optimal separation in High Pressure Liquid Chromatography (HPLC). This manuscript briefly outlines the theoretical background of the DOE and provides step-by-step instruction for its implementation in HPLC pharmaceutical practice. It particularly discusses the classification of various design types and their possibilities to rationalize the different stages of HPLC method development workflow, such as the selection of the most influential factors, factors optimization and assessment of the method robustness. Additionally, the application of the DOE-based Analytical Quality by Design (AQbD) concept in the LC method development has been summarized. Recent achievements in the use of DOE in the development of stability-indicating LC and hyphenated LC-MS methods have also been briefly reported. Performing of Quantitative structure retention relationship (QSRR) study enhanced with DOE-based data collection was recomended as a future perspective in description of retention in HPLC system.

Protocol development, validation, and troubleshooting of in-situ fiber optic bathless dissolution system (FODS) for a pharmaceutical drug testing

Currently, there is no systematic approach available for the validation, quantitative assessment, and troubleshooting for the in-situ fiber optic/bathless dissolution system (FODS). In this report, a dissolution protocol was developed and validated for a model product, chlorpheniramine maleate (CPM) 4 mg IR tablets. Dissolution runs were conducted at 37 ± 0.2 °C using a USP apparatus II, at 50 rpm in 500 mL of 0.01 N hydrochloric acid. The dissolution system was validated for linearity, accuracy, precision, specificity, and robustness analogously to an HPLC method validation. The linearity determination method was developed using five concentration levels between 25-125 % of the expected concentration, while for accuracy, 80 %, 100 %, and 120 % levels were used, and precision was determined using six runs at the 100 % level. Probe sampling depth, orientation, analytical wavelength, and paddle speed were varied to evaluate the robustness of the system tested. Method equivalence was established by comparing the dissolution results from FODS and the traditional dissolution method using UV spectrophotometry. Based on the statistics generated using the dissolution tests, the results are linear, accurate, precise, and specific. Robustness testing demonstrates that small changes in operating conditions did not significantly change the result. No significant difference in the amount dissolved at Q-timepoint was observed between FODS and traditional testing. Therefore, the FODS is a suitable alternative to traditional dissolution for CPM immediate-release tablets (many other drug products have been tested in the laboratory, and reports are in preparation). Additionally, the current work discusses problems related to media preparation, probe sensitivity, and excipient effects on data collected using FODS. The instrument-specific artifacts and data analysis problems are addressed and troubleshooting with possible solutions to eliminate or mitigate the errors. Although the FODS method was developed and evaluated using CPM in 500 mL dissolution volume, the dissolution method using a more common pharmacopoeial dissolution volume, i.e., 900 mL, was used to demonstrate the troubleshooting experiments for the drug products requiring 900 mL dissolution media.

A methodology employing retention modeling for achieving control space in liquid chromatography method development using quality by design approach

This study reports the application of retention modeling and quality by design practices for reverse-phase liquid chromatographic method development of a new chemical entity. Prior to the retention modeling, preliminary screening experiments were performed for the selection of stationary phase, organic modifiers, and method parameters. Based on the results of preliminary method conditions, t_G-T (gradient time - temperature) 2-D modeling with 4 input runs, and t_G-T-t_c (gradient time-temperature-ternary composition) 3-D modeling with 12 input runs were designed to build a model for achieving the optimized separation. Modeling of reverse phase separations was based on the measurement of both retention times and peak areas. A design space with appropriate input variables and control strategy was established prior to optimization and robustness evaluation following the quality by design framework. DryLab^Ⓡ was used to predict the optimized gradient profile and separation temperature. The robustness evaluation was carried out using the multiple factors at a time approach and the control space was established. The interdependence of control space and the control strategy was demonstrated by evaluating method robustness using two levels of system suitability criteria. The predictive accuracy of the retention modeling was established through experimental verification of the in-silico predictions. The quality by design based method development approach demonstrated the in-silico optimization as an integral component of reverse-phase chromatographic method development to evaluate the interplay of factors such as organic modifiers, separation temperature and gradient time, which greatly integrated and enhanced method robustness during method development.

Ultra high-performance liquid chromatography method development for separation of formoterol, budesonide, and related substances using an analytical quality by design approach

The application of the Quality by Design (QbD) principles in developing a new ultra high performance liquid chromatography method for the analysis of formoterol/budesonide and related substances using Fusion QbD® software is explored. The effect of various chromatographic parameters including, column stationary phase, pH, temperature, flow rate, and gradient time on separations were systematically investigated. Results show that optimal separations of these compounds in a standard solution can be achieved using a BEH C₁₈ column (2.1 × 1.7 μm × 10 cm) applying a pH of 8.2, a temperature of 35 °C, a flow rate of 0.35 mL min^-1 and a gradient time of 25 min. Furthermore, the results show that the main parameters affecting the performance of the method were the mobile phase pH, gradient time, and the temperature. For example, the most important factor for peak tailing was the pH of the mobile phase and the critical factors affecting resolution of the analytes were the gradient time and the temperature. As an application, the method was further used to analyze budesonide and formoterol in a sample obtained from a Symbicort® metered dose inhaler and it was found to provide similar separations to those obtained with the standard solution. These findings indicate that applying the QbD principles in analytical method development can be very advantageous not only in obtaining deep understanding of the effect of input parameters but also potential regulatory flexibility.

A Systematic AQbD Approach for Optimization of the Most Influential Experimental Parameters on Analysis of Fish Spoilage-Related Volatile Amines

The volatile amines trimethylamine (TMA) and dimethylamine (DMA) could be used as important spoilage indices for seafood products, assisting in the determination of the rejection period. In the present study, a systematic analytical duality-by-design (AQbD) approach was used as a powerful strategy to optimize the most important experimental parameters of headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) conditions for the quantification of TMA and DMA in Sparus aurata. This optimization enabled the selection of the best points in the method operable design region for HS-SPME extraction (30 min; 35 °C; NaOH 15 M and NaCl 35%, w/v) and GC-MS analysis (80 °C; gradient 50 °C/min; flow rate 1 mL/min and splitless mode). The rejection day, estimated through the TMA concentration (>12 mg/100 g, at days 9–10), was compared with sensory (quality index method: day 7–8), physical (Torrymeter: day 8–9), and microbial (day 9–10) analysis, corroborating the suitability of the proposed approach for estimating the period for which they will retain an acceptable level of eating quality from a safety and sensory perspective.

Rapid and efficient chiral method development for lamivudine and tenofovir disoproxil fumarate fixed dose combination using ultra-high performance supercritical fluid chromatography: A design of experiment approach

Fixed dose combination (FDC) of tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) is one of the most preferred FDC for the treatment of acquired immunodeficiency syndrome (AIDS)/human immunodeficiency virus (HIV) infection. To the best of authors' knowledge there are no reported methods for chiral purity estimation of both drugs simultaneously from a FDC. The current study was focused on the development of a single chiral method uisng supercritical fluid chromatography (SFC) for separation of stereoisomers of TDF and 3TC combination employing design of experiment (DoE) approach. Method development was planned in three steps by using different experimental designs for each step. I-optimal, Taguchi orthogonal array and face-centred central composite designs (CCD) were employed for primary parameter selection, secondary parameter screening and final method optimization, respectively. All six stereoisomers were separated in a 10 minute run on Chiralpak IA column with carbon di-oxide /methanol (containing 0.5 % v/v n-butylamine) as mobile phase at 1.5 mL/min in gradient mode. The optimized method was verified for performance through establishing specificity, precision, linearity, accuracy, limit of quantification, and solution stability. Resolution between each isomeric pair was more than 1.5. The method was found to be linear from 1.5 µg/mL to 7.5 µg/mL for 3TC and 7.5 µg/mL to 37.5 µg/mL for TDF stereoisomers. The R² values for all the linearity curves for undesired isomers were greater than 0.995. The method proved to be rapid, reproducible and efficient to quantify stereoisomers of both drugs in a single run.

Development of a Stability-Indicating Analytical Method for Determination of Venetoclax Using AQbD Principles

Venetoclax is an emerging drug for the treatment of various types of blood cancers. It was first approved in 2016 for the treatment of relapsed and refractory chronic lymphocytic leukemia. Later, the indications expanded, and multiple research as well as clinical studies are still conducted involving venetoclax. No analytical method for the determination of venetoclax can currently be found in the literature. We developed a mass spectrometry-compatible stability-indicating ultrahigh-performance liquid chromatography (LC) method for venetoclax. The LC method was developed using analytical quality by design principles. The developed method is able to separate venetoclax and its degradation products. The method was validated in the working point where a linearity range was established and accuracy, repeatability, and selectivity were assessed. Venetoclax is the only Bcl-2 protein inhibitor on the market. It is very effective in combinational therapy, so future drug development involving venetoclax may be expected. A stability-indicating method could aid in the development of new pharmaceutical products with venetoclax.

Developing an Improved UHPLC Method for Efficient Determination of European Pharmacopeia Process-Related Impurities in Ropinirole Hydrochloride Using Analytical Quality by Design Principles

This article presents the development of a reversed-phase ultra-high-performance liquid chromatographic method for determining process-related impurities in ropinirole hydrochloride drug substance applying the analytical quality by design approach. The current pharmacopeial method suffers from selectivity issues due to two coelutions of two pairs of impurities. The development of a new method began with preliminary experiments, based on which the Acquity UPLC BEH C8 was selected as the most appropriate column. The effects of six different critical method parameters (CMPs) were then investigated using a fractional factorial screening design. Column temperature, the ratio of methanol in mobile phase B, and gradient slope turned out to be highly significant CMPs in achieving critical resolutions, and they were further evaluated using a central composite face-centered response-surface design. Mathematical models were created by applying a multiple linear regression method. Based on the elution order of an unknown degradation impurity and impurity C, two design spaces were established, and for each design space an optimal combination of CMPs was determined. The method developed was validated for precision, accuracy, linearity, and sensitivity, and it was proven suitable for determining nine process-related impurities of ropinirole.