Latent variable modeling to assist the implementation of Quality-by-Design paradigms in pharmaceutical development and manufacturing: A review

A novel strategy for the quality control of carbonized Typhae pollen using colorimeter, liquid chromatography-mass spectrometry, and efficacy evaluation coupled with multivariate statistical analysis

In this study, a novel quality control strategy was proposed, aiming to establish a multivariate specification for the processing step by exploring the correlation between colors, chemical components, and hemostatic effects of the carbonized Typhae pollen (CTP) using multivariate statistical analysis. The CTP samples were stir-fried at different durations. Afterward, the colorimeter and LC-MS techniques were applied to characterize the CTP samples, followed by the determination of bleeding time and clotting time using mice to evaluate their hemostatic effect. Then, principal component analysis, hierarchical cluster analysis, and multi-block partial least squares were used for data analysis on colors, chemical components, and their correlation with the hemostatic effect. Consequently, 13 critical quality attributes (CQAs) of CTP were identified via multivariate statistical analysis-L*, a*, b*, 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, quercetin-3-O-glucoside, azelaic acid, kaempferol-3-O-glucoside, quercetin, naringenin, kaempferol, and isorhamnetin. The multivariate specification method involving the 13 CQAs was developed and visualized in the latent variable space of the partial least squares model, indicating that the proposed method was successfully applied to assess the quality of CTP and the degree of carbonization. Most importantly, this study offers a novel insight into the control of processing for carbonized Chinese herbal medicines.

Question-based review for pharmaceutical development: An enhanced quality approach

Over the last years, the pharmaceutical industry has faced real challenges regarding quality assurance. In this context, the establishment of more holistic approaches to the pharmaceutical development has been encouraged. The emergence of the Quality by Design (QbD) paradigm as systematic, scientific and risk-based methodology introduced a new concept of pharmaceutical quality. In essence, QbD can be interpreted as a strategy to maximize time and cost savings. An in-depth understanding of the formulation and manufacturing process is demanded to optimize the safety, efficacy and quality of a drug product at all stages of development. This innovative approach streamlines the pharmaceutical Research and Development (R&D) process, provides greater manufacturing flexibility and reduces regulatory burden. To assist in QbD implementation, International Conference on Harmonisation (ICH), U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) organized and launched QbD principles in their guidance for industry, identifying key concepts and tools to design and develop a high-quality drug product. Despite the undeniable advantages of the QbD approach, and the widespread information on QbD regulatory expectations, its full implementation in the pharmaceutical field is still limited. The present review aims to establish a crosswise overview on the current application status of QbD within the framework of the ICH guidelines (ICH Q8(R2) - Q14 and ICH Q2(R2)). Moreover, it outlines the way information gathered from the QbD methodology is being harmonized in Marketing Authorization Applications (MAAs) for European market approval. This work also highlights the challenges that hinder the deployment of the QbD strategy as a standard practice.

Implementation of Quality by Design (QbD) for development of bilayer tablets

Bilayer tablets offer various drug release profiles for individual drugs incorporated in each layer of a bilayer tablet, which is rarely achievable by conventional tablets. These tablets also help avoid physicochemical incompatibilities between drugs and excipients. Successful manufacturing of such more complex dosage forms depends upon screening of material attributes of API and excipients as well as optimization of processing parameters of individual unit operations of the manufacturing process that must be strictly monitored and controlled to obtain an acceptable drug product quality and performance in order to achieve safety and efficacy per regulatory requirements. Optimizing formulation attributes and manufacturing processes during critical stages, such as blending, granulation, pre-compression, and main compression, can help avoid problems such as weight variation, segregation, and delamination of individual layers, which are frequently faced during the production of bilayer tablets. The main objective of this review is to establish the basis for the implementation of Quality by Design (QbD) system principles for the design and development of bilayer tablets, encompassing the preliminary and systematic risk assessment of critical material attributes (CMAs) and critical process parameters (CPPs) with respect to in-process and finished product critical quality attributes (CQAs). Moreover, the applicability of the QbD methodology based on its purpose is discussed and complemented with examples of bilayer tablet technology.

Quality by Design Approach in Liposomal Formulations: Robust Product Development

Nanomedicine is an emerging field with continuous growth and differentiation. Liposomal formulations are a major platform in nanomedicine, with more than fifteen FDA-approved liposomal products in the market. However, as is the case for other types of nanoparticle-based delivery systems, liposomal formulations and manufacturing is intrinsically complex and associated with a set of dependent and independent variables, rendering experiential optimization a tedious process in general. Quality by design (QbD) is a powerful approach that can be applied in such complex systems to facilitate product development and ensure reproducible manufacturing processes, which are an essential pre-requisite for efficient and safe therapeutics. Input variables (related to materials, processes and experiment design) and the quality attributes for the final liposomal product should follow a systematic and planned experimental design to identify critical variables and optimal formulations/processes, where these elements are subjected to risk assessment. This review discusses the current practices that employ QbD in developing liposomal-based nano-pharmaceuticals.

Recent Advances in Freeze-Drying: Variables, Cycle Optimization, and Innovative Techniques

Freeze-drying (FD) is the most substantial drying technique utilized in the pharmaceutical and biopharmaceutical industries. It is a drying process where the solvent is crystallized at low temperatures and then sublimed from the solid-state directly into the vapor phase. Although FD possesses several merits as its suitability for thermolabile materials and its ability to produce dry products with high-quality attributes, it is a complex and prolonged process that requires optimization of both; process and formulation variables. This review attains to disassemble freeze-drying complications through a detailed explanation of the lyophilization concept, stages, the factors influencing the process including controlled ice nucleation, and the modified and innovative freeze-drying technologies proposed in recent years to overcome the shortage of traditional freeze-drying. In addition, this work points out the quality by design (QbD), critical quality of attributes (CQAs), limitations, and drawbacks of lyophilization.HighlightsLyophilization is a propitious drying technique for thermolabile materials.Optimizing the lyophilization cycle requires controlling the process parameters.The formulation excipients and the dispersion medium play crucial roles in designing a successful process.Numerous approaches were developed to ameliorate the lyophilization performance.

A benchmark simulator for quality-by-design and quality-by-control studies in continuous pharmaceutical manufacturing - Intensified filtration-drying of crystallization slurries

This article introduces ContCarSim, a benchmark simulator for the development and testing of quality-by-design and quality-by-control strategies in the continuous intensified filtration-drying of paracetamol/ethanol slurries on a novel carousel technology, developed by Alconbury Weston Ltd (United Kingdom). The simulator is based on a detailed mechanistic mathematical modeling framework, and has been validated with filtration and drying experiments on a prototype equipment. A set of design- and control-relevant challenges to be addressed through ContCarSim are proposed. A case study is developed, to demonstrate the features of the simulator and its suitability to design, test and optimize the unit operation. ContCarSim is expected to promote the transition to end-to-end continuous pharmaceutical manufacturing and the adoption of closed-loop quality control by the pharmaceutical industry. The simulator can also be employed as a benchmark for data analytics and process monitoring studies.

A review on the modernization of pharmaceutical development and manufacturing - Trends, perspectives, and the role of mathematical modeling

Recently, the pharmaceutical industry has been facing several challenges associated to the use of outdated development and manufacturing technologies. The return on investment on research and development has been shrinking, and, at the same time, an alarming number of shortages and recalls for quality concerns has been registered. The pharmaceutical industry has been responding to these issues through a technological modernization of development and manufacturing, under the support of initiatives and activities such as quality-by-design (QbD), process analytical technology, and pharmaceutical emerging technology. In this review, we analyze this modernization trend, with emphasis on the role that mathematical modeling plays within it. We begin by outlining the main socio-economic trends of the pharmaceutical industry, and by highlighting the life-cycle stages of a pharmaceutical product in which technological modernization can help both achieve consistently high product quality and increase return on investment. Then, we review the historical evolution of the pharmaceutical regulatory framework, and we discuss the current state of implementation and future trends of QbD. The pharmaceutical emerging technology is reviewed afterwards, and a discussion on the evolution of QbD into the more effective quality-by-control (QbC) paradigm is presented. Further, we illustrate how mathematical modeling can support the implementation of QbD and QbC across all stages of the pharmaceutical life-cycle. In this respect, we review academic and industrial applications demonstrating the impact of mathematical modeling on three key activities within pharmaceutical development and manufacturing, namely design space description, process monitoring, and active process control. Finally, we discuss some future research opportunities on the use of mathematical modeling in industrial pharmaceutical environments.

Pharmaceutical application of multivariate modelling techniques: a review on the manufacturing of tablets

The tablet manufacturing process is a complex system, especially in continuous manufacturing (CM). It includes multiple unit operations, such as mixing, granulation, and tableting. In tablet manufacturing, critical quality attributes are influenced by multiple factorial relationships between material properties, process variables, and interactions. Moreover, the variation in raw material attributes and manufacturing processes is an inherent characteristic and seriously affects the quality of pharmaceutical products. To deepen our understanding of the tablet manufacturing process, multivariable modeling techniques can replace univariate analysis to investigate tablet manufacturing. In this review, the roles of the most prominent multivariate modeling techniques in the tablet manufacturing process are discussed. The review mainly focuses on applying multivariate modeling techniques to process understanding, optimization, process monitoring, and process control within multiple unit operations. To minimize the errors in the process of modeling, good modeling practice (GMoP) was introduced into the pharmaceutical process. Furthermore, current progress in the continuous manufacturing of tablets and the role of multivariate modeling techniques in continuous manufacturing are introduced. In this review, information is provided to both researchers and manufacturers to improve tablet quality.

Optimization of membrane dispersion ethanol precipitation process with a set of temperature control improved equipment

Ethanol precipitation is an important separation and purification process in the traditional Chinese medicines (TCMs) industry. In the present study, a membrane dispersion micromixer was applied to achieve good mixing for the ethanol precipitation process of Astragali radix concentrate. New experimental apparatus was set up to rapidly lower the temperature of ethanol solution before mixing with the concentrate. Ethanol precipitation process was optimized according to Quality by design concept. To identify critical material attributes (CMAs), ten batches of Astragali radix were used to prepare concentrates. Calycosin-7-O-β-D-glucoside content, the sucrose content, and the electrical conductivity were found to be CMAs after the correlation analysis and stepwise regression modelling. Definitive screening design was used to investigate the relationships among critical process parameters, CMAs, and process critical quality attributes (CQAs). Quadratic models were developed and design space was calculated according to the probability of attaining process CQA standards. A material quality control strategy was proposed. High quality and low quality Astragali radix concentrates can be discriminated by the inequalities. Low quality Astragali radix concentrates should not be released for ethanol precipitation process directly. Verification experiment results indicated accurate models and reliable design space. The temperature control method and control strategy are promising for ethanol precipitation process of other TCMs or foods.

Multivariate Six Sigma: A Case Study in Industry 4.0

The complex data characteristics collected in Industry 4.0 cannot be efficiently handled by classical Six Sigma statistical toolkit based mainly in least squares techniques. This may refrain people from using Six Sigma in these contexts. The incorporation of latent variables-based multivariate statistical techniques such as principal component analysis and partial least squares into the Six Sigma statistical toolkit can help to overcome this problem yielding the Multivariate Six Sigma: a powerful process improvement methodology for Industry 4.0. A multivariate Six Sigma case study based on the batch production of one of the star products at a chemical plant is presented.

A Novel Framework to Aid the Development of Design Space across Multi-Unit Operation Pharmaceutical Processes-A Case Study of Panax Notoginseng Saponins Immediate Release Tablet

The fundamental principle of Quality by Design (QbD) is that the product quality should be designed into the process through an upstream approach, rather than be tested in the downstream. The keystone of QbD is process modeling, and thus, to develop a process control strategy based on the development of design space. Multivariate statistical analysis is a very useful tool to support the implementation of QbD in pharmaceutical process development and manufacturing. Nowadays, pharmaceutical process modeling is mainly focused on one-unit operations and system modeling for the development of design space across multi-unit operations is still limited. In this study, a general procedure that gives a holistic view for understanding and controlling the process settings for the entire manufacturing process was investigated. The proposed framework was tested on the Panax Notoginseng Saponins immediate release tablet (PNS IRT) production process. The critical variables and the critical units acting on the process were identified according to the importance of explaining the variability in the multi-block partial least squares path model. This improved understanding of the process by illustrating how the properties of the raw materials, the process parameters in the wet granulation and the compaction and the intermediate properties affect the tablet properties. Furthermore, the design space was developed to compensate for the variability source from the upstream. The results demonstrated that the proposed framework was an important tool to gain understanding and control the multi-unit operation process.

Development of immediate release Rupatadine fumarate 10 mg tablets: A Quality by Design (QbD) approach

Objective: The main objective of this research is to develop an immediate release Rupatadine fumarate 10 mg tablets formulation by direct compression, through a Quality by Design approach in Costa Rica. Methods: According to a Quality by Design approach; Target Product Profile, Quality Target Product Profile, and the Critical Quality Attributes were defined. In the preformulation study, compatibility tests were carried out between the raw materials. The Critical Material Attributes were established using Quality Risk Management. Three formulation prototypes were prepared by direct compression and its Critical Process Parameters were defined. The analysis of the prototypes was realized in terms of organoleptic properties, identification, potency, content uniformity, dissolution, disintegration, friability and loss by drying. Results: All the prototypes showed a white or slightly pink surface, potency between 90.0 -110.0 % of the labeling, an acceptance value for the content uniformity lower than the specification (AV < 15), the dissolved amount of active pharmaceutical ingredient was greater than 85.0 % at 30 minutes, friability less than 1.0 %, a disintegration time less than 15 minutes and moisture content less than 2.0 %. Conclusions: The approaching of a Quality by Design model to the current development allowed to obtain satisfactory results in the three formulation prototypes. The excipients to be used can be lactose monohydrate, microcrystalline cellulose, sodium croscarmellose, pregelatinized starch, magnesium stearate, stearic acid, and PVP K-30.

Data analytics on raw material properties to accelerate pharmaceutical drug development

Manufacturability of active pharmaceutical ingredients (APIs) is often evaluated by an empirical approach during development due to limited material availability. This brings challenges in designing flexible yet robust manufacturing processes under highly accelerated timelines. Hence, good utilisation of a limited material dataset is key to accelerate the delivery of high quality final drug product into the market at minimum cost and maximum process capacity. In this study, we present a data-driven method to investigate a raw materials database where the integration of multivariate analysis and machine learning modelling aids the selection of new incoming materials based on their manufacturability. The procedure was applied to an industrial representative database of thirty-four APIs and seven excipients where eight measurements relevant to flow properties for each of those forty-one materials were collected. The models identified four clusters of materials with different flow properties. These models can serve as a risk assessment tool for new API in early product development phases based on the nearest surrogate material which behave similarly, as well as to identify targeted and material sparring experiments to address key risks during secondary process selection.

Tableting performance of various mannitol and lactose grades assessed by compaction simulation and chemometrical analysis

Mannitol and lactose are commonly used fillers in pharmaceutical tablets, available in several commercial grades that are produced using different manufacturing processes. These grades significantly differ in particulate and powder properties that impact tablet manufacturability. Choice of sub-optimum type or grade of excipient in tablet formulation can lead to manufacturing problems and difficulties, which are magnified during a continuous manufacturing process. Previous characterization of tableting performance of these materials was limited in scope and under conditions not always realistic to the commercial production of tablets. This work seeks to comprehensively characterize the compaction properties of 11 mannitol and 5 lactose grades using a compaction simulator at both slow and fast tableting speeds. These include tabletability, compressibility, tablet brittleness, die-wall stress transmission, and strain rate sensitivity. A chemometrical analysis of data, using the partial least square technique, was performed to construct a model to provide accurate prediction of tablet tensile strength for mannitol grades. Such knowledge facilitates the selection of suitable tablet filler to attain high quality tablet products.

Improved synthesis and characterization of cholesteryl oleate-loaded cationic solid lipid nanoparticles with high transfection efficiency for gene therapy applications

The development of new nanoparticle formulations that are capable of high transfection efficiency without toxicity is essential to provide new tools for gene therapy. However, the issues of complex, poorly reproducible manufacturing methods, and low efficiencies during in vivo testing have prevented translation to the clinic. We have previously reported the use of cholesteryl oleate as a novel excipient for solid lipid nanoparticles (SLNs) for the development of highly efficient and nontoxic nucleic acid delivery carriers. Here, we performed an extensive characterization of this novel formulation to make the scale up under Good Manufacturing Practice (GMP) possible. We also describe the complete physicochemical and biological characterization of cholesteryl oleate-loaded SLNs to ensure the reproducibility of this formula and the preservation of its characteristics before and after the lyophilization process. We defined the best manufacturing method and studied the influence of some parameters on the obtained nanoparticles using the Quality by Design (ICH Q8) guideline to obtain cholesteryl oleate-loaded SLNs that remain stable during storage and guarantee in vitro nucleic acid delivery efficacy. Our results indicate that this improved formulation is suitable for gene therapy with the possibility of scale-up the manufacturing of nanoparticles under GMP conditions.

Optimal Selection of Incoming Materials from the Inventory for Achieving the Target Drug Release Profile of High Drug Load Sustained-Release Matrix Tablet

In the pharmaceutical process, raw material (including APIs and excipients) variability can be delivered to the final product, and lead to batch-to-batch and lot-to-lot variances in its quality, finally impacting the efficacy of the drug. In this paper, the Panax notoginseng saponins (PNS) sustained-release matrix tablet was taken as the model formulation. Hydroxypropyl methylcellulose with the viscosity of 4000 mPa·s (HPMCK4M) from different vendors and batches were collected and their physical properties were characterized by the SeDeM methodology. The in-vitro dissolution profiles of active pharmaceutical ingredients (APIs) from matrix tablets made up of different batches HPMC K4M displayed significant variations. Multi-block partial least squares (MB-PLS) modeling results further demonstrated that physical properties of excipients played dominant roles in the drug release. In order to achieve the target drug release profile with respect to those far from the criteria, the optimal selection method of incoming materials from the available was established and validated. This study provided novel insights into the control of the input variability of the process and amplified the application of the SeDeM expert system, emphasizing the importance of the physical information of the raw materials in the drug manufacturing process.

Pharmaceutical Additive Manufacturing: a Novel Tool for Complex and Personalized Drug Delivery Systems

Inter-individual variability is always an issue when treating patients of different races, genders, ages, pharmacogenetics, and pharmacokinetic characteristics. However, the development of novel dosage forms is limited by the huge investments required for production line modifications and dosages diversity. Additive manufacturing (AM) or 3D printing can be a novel alternative solution for the development of controlled release dosages because it can produce personalized or unique dosage forms and more complex drug-release profiles. The primary objective of this manuscript is to review the 3D printing processes that have been used in the pharmaceutical area, including their general aspects, materials, and the operation of each AM technique. Advantages and shortcomings of the technologies are discussed with respect to practice and practical applications. Thus, this review will provide an overview and discussion on advanced pharmaceutical AM technologies, which can be used to produce unique controlled drug delivery systems and personalized dosages for the future of personalized medicine.

Effects of Formulation and Process Variables on Gastroretentive Floating Tablets with A High-Dose Soluble Drug and Experimental Design Approach

To develop sustained release gastro-retentive effervescent floating tablets (EFT), a quality-based experimental design approach was utilized during the composing of a hydrophilic matrix loaded with a high amount of a highly water-soluble model drug, metformin HCl. Effects of the amount of polyethylene oxide WSR 303 (PEO), sodium bicarbonate, and tablet compression force were used as independent variables. Various times required to release the drug, tablet tensile strength, floating lag time, tablet ejection force, and tablet porosity, were selected as the responses. Polymer screening showed that PEO had the highest gel strength among the various tested polymers. Sodium bicarbonate had the most significant effect on the release rate and floating lag time by retarding the rate from the hydrophilic matrices, whilst tablet compression force and PEO exerted the greatest influence on tablet properties (p < 0.0001). The design space was built in accordance with the drug release profiles, tensile strength, and floating lag time, following failure probability analysis using Monte Carlo simulations. The kinetic modeling revealed that the release mechanism was best described by the Korsmeyer-Peppas model. Overall, the current study provided a perspective on the systematic approach of gastro-retentive EFT, loaded with highly water-soluble drugs by applying quality by design concepts.

Setting up multivariate specifications on critical raw material attributes to ensure consistent drug dissolution from high drug-load sustained-release matrix tablet

The purpose of this study was to describe the raw material variability that influenced the in-vitro dissolution behavior of high drug-load sustained-release matrix tablet and to ensure the consistent quality of the final product. The Panax notoginseng saponins (PNS) - hydroxypropyl methylcellulose - anhydrous lactose - magnesium stearate (57:20:23:0.5%, w/w) was used as the model formulation. PNS extract powders with lot-to-lot and source-to-source differences were collected to cover the common cause variations and their physicochemical properties were characterized by the chromatographic fingerprints and the SeDeM expert system. It was found that the release behavior of active pharmaceutical ingredients (APIs) in PNS from different batches exhibited considerable variations. Latent variable modeling results demonstrated that the physical properties of raw materials played major roles in predicting the drug dissolution. PNS extracts with high specific surface area, the width of particle size distribution and hygroscopicity or low moisture content led to an increase in drug release. In order to perform efficient pass/fail judgments for incoming new materials, multivariate specifications of critical material attributes (CMAs) were established and the multivariate design space in line with the quality by design (QbD) principles was explored to achieve the release target.

A practical framework for implementing Quality by Design to the development of topical drug products: Nanosystem-based dosage forms

Skin has been increasingly recognized as an important drug administration route with topical formulations, offering a targeted approach for the treatment of several dermatological disorders. The effectiveness of this route is hampered by its natural barrier, the stratum corneum (SC), and hence, different strategies have been investigated to improve percutaneous drug transport. The design of nanodelivery systems, aiming at solving skin delivery issues, have been largely explored, due to their potential to revolutionize dermal therapies, improving therapeutic effectiveness and reducing side effects. Apart from nanosystem benefits, the fulfilment of the reproducibility requirements and quality standards still limit their industrial production. The optimization of nanosystem formulation and manufacturing process is complex, usually involving a large number of variables. Therefore, a science- and risk-oriented approach, such as Quality by Design (QbD) will provide a comprehensive and noteworthy knowledge, yielding high quality drug products without extensive regulatory burden. This review aims to set up the basis for QbD development approach, encompassing preliminary and systematic risk assessments, with critical process parameters (CPPs) and critical material attributes (CMAs) identification, of different nanosystems potentially used in dermal therapies.

A Tutorial for Developing a Topical Cream Formulation Based on the Quality by Design Approach

The pharmaceutical industry has entered in a new era, as there is a growing interest in increasing the quality standards of dosage forms, through the implementation of more structured development and manufacturing approaches. For many decades, the manufacturing of drug products was controlled by a regulatory framework to guarantee the quality of the final product through a fixed process and exhaustive testing. Limitations related to the Quality by Test system have been widely acknowledged. The emergence of Quality by Design (QbD) as a systematic and risk-based approach introduced a new quality concept based on a good understanding of how raw materials and process parameters influence the final quality profile. Although the QbD system has been recognized as a revolutionary approach to product development and manufacturing, its full implementation in the pharmaceutical field is still limited. This is particularly evident in the case of semisolid complex formulation development. The present review aims at establishing a practical QbD framework to describe all stages comprised in the pharmaceutical development of a conventional cream in a comprehensible manner.

Relationships between response surfaces for tablet characteristics of placebo and API-containing tablets manufactured by direct compression method

In this study, we evaluated the correlation between the response surfaces for the tablet characteristics of placebo and active pharmaceutical ingredient (API)-containing tablets. The quantities of lactose, cornstarch, and microcrystalline cellulose were chosen as the formulation factors. Ten tablet formulations were prepared. The tensile strength (TS) and disintegration time (DT) of tablets were measured as tablet characteristics. The response surfaces for TS and DT were estimated using a nonlinear response surface method incorporating multivariate spline interpolation, and were then compared with those of placebo tablets. A correlation was clearly observed for TS and DT of all APIs, although the value of the response surfaces for TS and DT was highly dependent on the type of API used. Based on this knowledge, the response surfaces for TS and DT of API-containing tablets were predicted from only two and four formulations using regression expression and placebo tablet data, respectively. The results from the evaluation of prediction accuracy showed that this method accurately predicted TS and DT, suggesting that it could construct a reliable response surface for TS and DT with a small number of samples. This technique assists in the effective estimation of the relationships between design variables and pharmaceutical responses during pharmaceutical development.

Quality by Design (QbD) approach to optimize the formulation of a bilayer combination tablet (Telmiduo®) manufactured via high shear wet granulation

A bilayer tablet, which consisted of telmisartan and amlodipine besylate, was formulated based on a Quality by Design (QbD) approach. The control and response factors were determined based on primary knowledge and the target values of the control tablet (Twynsta^®). A D-optimal mixture design was used to obtain the optimal formulations in terms of D-mannitol, crospovidone, and MCC for the telmisartan layer, and CCM-Na, PVP K25, and Prosolv for the amlodipine layer. The quantitative effects of the different formulation factors on the response factors were accurately predicted using the equations of best fit and a strong linearity was observed between the predicted and actual values of the response factors. The optimized bilayer tablet was obtained using a numeric optimization technique and was characterized compared with a control (Twynsta^®) by using various physical evaluations and in vivo pharmacokinetic parameters. The physical stability of Telmiduo^® was greater than that of Twynsta^® owing to the improvement of formulation factors. The in vivo pharmacokinetic parameters suggested that Telmiduo^® might have pharmaceutical equivalence and bioequivalence with Twynsta^®. Therefore, the bilayer tablet that consisted of telmisartan and amlodipine besylate could be produced using a more economical and simpler method than that used to produce Twynsta^®. Moreover, the suitability of QbD for effective product development in the pharmaceutical industry was shown.

Multivariate Analysis and Statistics in Pharmaceutical Process Research and Development

The application of statistics in pharmaceutical process research and development has evolved significantly over the past decades, motivated in part by the introduction of the Quality by Design paradigm, a landmark change in regulatory expectations for the level of scientific understanding associated with the manufacturing process. Today, statistical methods are increasingly applied to accelerate the characterization and optimization of new drugs created via numerous unit operations well known to the chemical engineering discipline. We offer here a review of the maturity in the implementation of design of experiment techniques, the increased incorporation of latent variable methods in process and material characterization, and the adoption of Bayesian methodology for process risk assessment.

Modeling in the quality by design environment: Regulatory requirements and recommendations for design space and control strategy appointment

Mathematical models can be used as an integral part of the quality by design (QbD) concept throughout the product lifecycle for variety of purposes, including appointment of the design space and control strategy, continual improvement and risk assessment. Examples of different mathematical modeling techniques (mechanistic, empirical and hybrid) in the pharmaceutical development and process monitoring or control are provided in the presented review. In the QbD context, mathematical models are predominantly used to support design space and/or control strategies. Considering their impact to the final product quality, models can be divided into the following categories: high, medium and low impact models. Although there are regulatory guidelines on the topic of modeling applications, review of QbD-based submission containing modeling elements revealed concerns regarding the scale-dependency of design spaces and verification of models predictions at commercial scale of manufacturing, especially regarding real-time release (RTR) models. Authors provide critical overview on the good modeling practices and introduce concepts of multiple-unit, adaptive and dynamic design space, multivariate specifications and methods for process uncertainty analysis. RTR specification with mathematical model and different approaches to multivariate statistical process control supporting process analytical technologies are also presented.

Case Studies in Modelling, Control in Food Processes

This chapter discusses the importance of modelling and control in increasing food process efficiency and ensuring product quality. Various approaches to both modelling and control in food processing are set in the context of the specific challenges in this industrial sector and latest developments in each area are discussed. Three industrial case studies are used to demonstrate the benefits of advanced measurement, modelling and control in food processes. The first case study illustrates the use of knowledge elicitation from expert operators in the process for the manufacture of potato chips (French fries) and the consequent improvements in process control to increase the consistency of the resulting product. The second case study highlights the economic benefits of tighter control of an important process parameter, moisture content, in potato crisp (chips) manufacture. The final case study describes the use of NIR spectroscopy in ensuring effective mixing of dry multicomponent mixtures and pastes. Practical implementation tips and infrastructure requirements are also discussed.

Statistical modeling methods to analyze the impacts of multiunit process variability on critical quality attributes of Chinese herbal medicine tablets

The quality of Chinese herbal medicine tablets suffers from batch-to-batch variability due to a lack of manufacturing process understanding. In this paper, the Panax notoginseng saponins (PNS) immediate release tablet was taken as the research subject. By defining the dissolution of five active pharmaceutical ingredients and the tablet tensile strength as critical quality attributes (CQAs), influences of both the manipulated process parameters introduced by an orthogonal experiment design and the intermediate granules’ properties on the CQAs were fully investigated by different chemometric methods, such as the partial least squares, the orthogonal projection to latent structures, and the multiblock partial least squares (MBPLS). By analyzing the loadings plots and variable importance in the projection indexes, the granule particle sizes and the minimal punch tip separation distance in tableting were identified as critical process parameters. Additionally, the MBPLS model suggested that the lubrication time in the final blending was also important in predicting tablet quality attributes. From the calculated block importance in the projection indexes, the tableting unit was confirmed to be the critical process unit of the manufacturing line. The results demonstrated that the combinatorial use of different multivariate modeling methods could help in understanding the complex process relationships as a whole. The output of this study can then be used to define a control strategy to improve the quality of the PNS immediate release tablet.

Latent variable modeling to analyze the effects of process parameters on the dissolution of paracetamol tablet

The dissolution is one of the critical quality attributes (CQAs) of oral solid dosage forms because it relates to the absorption of drug. In this paper, the influence of raw materials, granules and process parameters on the dissolution of paracetamol tablet was analyzed using latent variable modeling methods. The variability in raw materials and granules was understood based on the principle component analysis (PCA), respectively. A multi-block partial least squares (MBPLS) model was used to determine the critical factors affecting the dissolution. The results showed that the binder amount, the post granulation time, the API content in granule, the fill depth and the punch tip separation distance were the critical factors with variable importance in the projection (VIP) values larger than 1. The importance of each unit of the whole process was also ranked using the block importance in the projection (BIP) index. It was concluded that latent variable models (LVMs) were very useful tools to extract information from the available data and improve the understanding on dissolution behavior of paracetamol tablet. The obtained LVMs were also helpful to propose the process design space and to design control strategies in the further research.

Application of quality by design in the current drug development

Quality by Test was the only way to guarantee quality of drug products before FDA launched current Good Manufacturing Practice. To clearly understand the manufacture processes, FDA generalized Quality by Design (QbD) in the field of pharmacy, which is based on the thorough understanding of how materials and process parameters affect the quality profile of final products. The application of QbD in drug formulation and process design is based on a good understanding of the sources of variability and the manufacture process. In this paper, the basic knowledge of QbD, the elements of QbD, steps and tools for QbD implementation in pharmaceutics field, including risk assessment, design of experiment, and process analytical technology (PAT), are introduced briefly. Moreover, the concrete applications of QbD in various pharmaceutical related unit operations are summarized and presented.

New aspects of developing a dry powder inhalation formulation applying the quality-by-design approach

The current work outlines the application of an up-to-date and regulatory-based pharmaceutical quality management method, applied as a new development concept in the process of formulating dry powder inhalation systems (DPIs). According to the Quality by Design (QbD) methodology and Risk Assessment (RA) thinking, a mannitol based co-spray dried formula was produced as a model dosage form with meloxicam as the model active agent. The concept and the elements of the QbD approach (regarding its systemic, scientific, risk-based, holistic, and proactive nature with defined steps for pharmaceutical development), as well as the experimental drug formulation (including the technological parameters assessed and the methods and processes applied) are described in the current paper. Findings of the QbD based theoretical prediction and the results of the experimental development are compared and presented. Characteristics of the developed end-product were in correlation with the predictions, and all data were confirmed by the relevant results of the in vitro investigations. These results support the importance of using the QbD approach in new drug formulation, and prove its good usability in the early development process of DPIs. This innovative formulation technology and product appear to have a great potential in pulmonary drug delivery.

Hot-Melt Extrusion: from Theory to Application in Pharmaceutical Formulation

Hot-melt extrusion (HME) is a promising technology for the production of new chemical entities in the developmental pipeline and for improving products already on the market. In drug discovery and development, industry estimates that more than 50% of active pharmaceutical ingredients currently used belong to the biopharmaceutical classification system II (BCS class II), which are characterized as poorly water-soluble compounds and result in formulations with low bioavailability. Therefore, there is a critical need for the pharmaceutical industry to develop formulations that will enhance the solubility and ultimately the bioavailability of these compounds. HME technology also offers an opportunity to earn intellectual property, which is evident from an increasing number of patents and publications that have included it as a novel pharmaceutical formulation technology over the past decades. This review had a threefold objective. First, it sought to provide an overview of HME principles and present detailed engineered extrusion equipment designs. Second, it included a number of published reports on the application of HME techniques that covered the fields of solid dispersions, microencapsulation, taste masking, targeted drug delivery systems, sustained release, films, nanotechnology, floating drug delivery systems, implants, and continuous manufacturing using the wet granulation process. Lastly, this review discussed the importance of using the quality by design approach in drug development, evaluated the process analytical technology used in pharmaceutical HME monitoring and control, discussed techniques used in HME, and emphasized the potential for monitoring and controlling hot-melt technology.

Macroscopic modeling of mammalian cell growth and metabolism

We review major modeling strategies and methods to understand and simulate the macroscopic behavior of mammalian cells. These strategies comprise two important steps: the first step is to identify stoichiometric relationships for the cultured cells connecting the extracellular inputs and outputs. In a second step, macroscopic kinetic models are introduced. These relationships together with bioreactor and metabolite balances provide a complete description of a system in the form of a set of differential equations. These can be used for the simulation of cell culture performance and further for optimization of production.

Quality-by-Design approach to monitor the operation of a batch bioreactor in an industrial avian vaccine manufacturing process

Monitoring batch bioreactors is a complex task, due to the fact that several sources of variability can affect a running batch and impact on the final product quality. Additionally, the product quality itself may not be measurable on line, but requires sampling and lab analysis taking several days to be completed. In this study we show that, by using appropriate process analytical technology tools, the operation of an industrial batch bioreactor used in avian vaccine manufacturing can be effectively monitored as the batch progresses. Multivariate statistical models are built from historical databases of batches already completed, and they are used to enable the real time identification of the variability sources, to reliably predict the final product quality, and to improve process understanding, paving the way to a reduction of final product rejections, as well as to a reduction of the product cycle time. It is also shown that the product quality "builds up" mainly during the first half of a batch, suggesting on the one side that reducing the variability during this period is crucial, and on the other side that the batch length can possibly be shortened. Overall, the study demonstrates that, by using a Quality-by-Design approach centered on the appropriate use of mathematical modeling, quality can indeed be built "by design" into the final product, whereas the role of end-point product testing can progressively reduce its importance in product manufacturing.

A review of pharmaceutical extrusion: critical process parameters and scaling-up

Hot melt extrusion has been a widely used process in the pharmaceutical area for three decades. In this field, it is important to optimize the formulation in order to meet specific requirements. However, the process parameters of the extruder should be as much investigated as the formulation since they have a major impact on the final product characteristics. Moreover, a design space should be defined in order to obtain the expected product within the defined limits. This gives some freedom to operate as long as the processing parameters stay within the limits of the design space. Those limits can be investigated by varying randomly the process parameters but it is recommended to use design of experiments. An examination of the literature is reported in this review to summarize the impact of the variation of the process parameters on the final product properties. Indeed, the homogeneity of the mixing, the state of the drug (crystalline or amorphous), the dissolution rate, the residence time, can be influenced by variations in the process parameters. In particular, the impact of the following process parameters: temperature, screw design, screw speed and feeding, on the final product, has been reviewed.