Introduction to Quality by Design for Pharmaceuticals by Nilesh Desai, Manohar A. Potdar – Ebook | Scribd

CHAPTER 1

OVERVIEW OF QbD

1.1 INTRODUCTION

Quality of product is of utmost important in pharmaceutical manufacturing. FDA continually sets certain standards to obtain quality medicines to the patients. They also try to identify ways to encourage manufacturers to improve manufacturing processes to ensure consistent product quality throughout the product’s life cycle. The quality is main concern for any manufacturing process because of its direct impact on patient’s health. The economic growth of any company also depends on quality of product.

In pharmaceutical products, the quality is the function of drug substance, excipients, manufacturing and packaging processes. If we want desired quality in the final product, it must be built into the product. To ensure this, we require thorough understanding of how material attributes, process parameters and formulation parameters influence product quality.

The main need of any product development is to obtain a quality product which can fulfill patients need. So in pharmaceutical development process, the final products should be designed as such to meet patients’ needs and to achieve intended product performance. There are various steps involved in development of product in which strategies are differing from company to company and from product to product. Up to date, the focus of researchers is to obtain quality product, whatever the approach and scope of development may be. On that basis, the researchers might choose either everyday approach (conventional) or a more systematic approach (advanced) or combination of both for product development. Now a days. FDA announced that every product development file must have Quality by Design (QbD) approach.¹

In order to describe QbD. we must first define what we mean by quality. Janet Woodcock (Director for the Centre for Drug Evaluation and Research) defined pharmaceutical quality as a “product that is free of contamination and reproducibly delivers the therapeutic benefit promised in the label to the consumer’.² Also “quality in manufacturing is a measure of excellence or a state of being free from defects, deficiencies, and significant variation’.

According to ICH Q8 guideline, QbD is a systematic approach to pharmaceutical development that begins with predefined objectives and emphasizes product and process understanding and process control, based on sound science and quality risk management.³ As QbD says more systematic approach to development, it can include combination of prior knowledge, design of experiments (DOE), quality risk management, and knowledge management (ICH Q10) throughout the product life cycle. When implementation of such systematic approach is carried out, improvement happens in the desired quality of the product and helps the regulators to better understand a company’s strategy.

QbD was first described by well-known quality expert Joseph M. Juran.⁴ Juran believed that quality could be planned, so that most quality crises and problems relate to quality will be diminished. His discovery of designed in concept is used in QbD for optimization of process/product. As per this concept, the quality attribute should be identified and designed through sy stematic implementation of an optimization strategy.

The foundation of QbD is to identify characteristics that are critical to quality from the perspective of patients, translates them into the attributes that the drug product should possess, and establishes how the critical process parameters can be varied to consistently produce a drug product with the desired characteristics. In order to do this the relationships between formulation and manufacturing process variables (including drug substance and excipient attributes and process parameters) and product characteristics are established and sources of variability identified. This knowledge is then used to implement a flexible and robust manufacturing process that we can adapt and produce a consistent product over time.⁵

Implementation of QbD is complex and challenging work in pharmaceutical industry. Many of the concepts, frameworks (agendas) and tools are new to pharma practitioners. Although it is implemented well, there is lot of confusion among practitioners about the use of QbD tools. QbD brought a shift in industry paradigm to move away from dependence on testing for quality to building quality into the design of the product and processes. This should in turn bring about a more scientific, technological and risk based approach.

The main objectives of Quality bv Design

•   To facilitate innovation and continuous improvement throughout the product lifecy cle

•   To achieve meaningful product quality specifications that are based on clinical performance

•   To provide regulatory flexibility for specification setting and postapproval changes

•   To increase process capability and reduce product variability and defects by enhancing product and process design, understanding, and control

•   To increase product development and manufacturing efficiencies

•   To enhance root cause analysis and postapproval change management

•   To streamline the submission and review processes

Table 1.1| Current state vs. Desired QbD state

As stated in Table 1.1, FDA recognizes that only increase in testing does not improve product quality, it also requires the systematic design approach. With the help of QbD various costs can be reduced such as testing cost, facility cost and resources cost. These costs are more in case of conventional quality by testing approach compared to QbD.

When considered the use of QbD over conventional method. QbD covers a better scientific understanding of critical process and product qualities. It also covers designing controls and tests based on the scientific limits which come by understanding during the development phase. Also it uses the knowledge obtained during the life-cy cle of the product to work on a constant improvement of product.

An important part of QbD is to understand how process and formulation parameters affect the product characteristics (also called critical quality attributes (CQA’s)) and subsequent optimization of these parameters should be identified in order to monitor these parameters on-line in the production process. QbD can also facilitate the use of innovative technologies and promote the use of new approaches to perform process validation, such as continuous quality verification.

Finally, QbD is an evolution and not a revolution” – an evolution that is in response to the increasing cost pressures on both the regulatory agencies and industry to control the increase of drug prices.⁶ QbD will continue to evolve for years to come as new tools and technologies advance to improve the way we mitigate risks and increase our understanding and control of the manufacturing processes. In addition to increasing quality, the pharmaceutical industry will reduce development and manufacturing cycle times as well as costs in the process.

1.2 HISTORY OF QbD

In the area of pharmaceutical quality improvement, FDA recognized that more and more controls should be required in the manufacturing processes for efficient drug product and also for better regulatory decision making. It resulted in more stringent regulatory background. On the basis of this, FDA announced proposed amendments to ‘’Current Good Manufacturing Practices” (cGMP) in 2002. According to this, an emphasis was given on establishing a 21st century guide on pharmaceutical manufacturing with a target of development in science and technology. For that there is need of establishing a more systematic science and risk based approach to the development of pharmaceutical products.

FDA released Guideline on General Principles of Process Validation in 1987. This guideline emphasize that process validation is complete with the 3 validation lots at the commercial scale. An alternative approach to this traditional process validation is the continuous process verification, also known as life-cycle approach which is the essence of the concept of QbD.

ICH (1999) defines the concept of quality and assists in the establishment of global specifications for new drug substances or drug products.⁷

FDA (2004) outlines the QbD concept and summarizes initiatives to encourage science-based policies and innovation in pharmaceutical development and manufacturing. Proposes risk assessment as a tool to evaluate the impact of variations in process inputs on product quality.⁸

FDA (2004) defines the industrialization process as the set of activities related to product design, process design and technology transfer. It acknowledges the problems in these steps which routinely disrupt or delay development programs.⁹

The initiation of the cGMPs for the 21st Century Initiative and the publication of the Process Analytical Technology (PAT) guidance in 2004 by the FDA construct the way for the modernization of the pharmaceutical industry. According to guidance, PAT is a system for designing, analyzing, and controlling manufacturing processes based on understanding of science and factors which affect the quality of final product. Also PAT is a framework for innovative pharmaceutical development, manufacturing and quality assurance.¹⁰

Finally in 2005, the time came to implement QbD for more systematic approach and USFDA asked some firms to submit their chemistry manufacturing control (CMC) in QbD format.⁹QbD involves thorough understanding of process; a goal or objective is defined before actual start of process.

Question based review (QbR) forms the platform of QbD principle.¹¹ QbR is a general framework, recommended as a submission format by the draft guidance for industry ANDA Submission – Content and Format of Abbreviated New Drug Applications, for a science and risk-based assessment of product quality. It contains important scientific and regulatory review questions related to product and process design and understanding, product performance, and control strategy. The QbR format was fully implemented for assessment of ANDAs in 2007. Revised questions were developed in 2012 and 2014 to better capture quality-by-design (QbD) expectations, incorporating both internal and external stakeholder feedback.

The key framework guidance documents for implementation of QbD are ICH Q8 Pharmaceutical Development, ICH Q9 Quality Risk Management (published in 2005) and ICH Q10 Pharmaceutical Quality System (published in 2008).

•   ICH Q8 Pharmaceutical Development focuses on the content of the Module 3.2.P.2 of the Common Technical Document (CTD) and promotes the concept of QbD. Final guideline Q8(R2) was published in 2008. It supports knowledge gained through the lifecycle of a product and using scientific approaches and quality risk management principles.

•   ICH Q9 Quality Risk Management defines risk and offers a systematic approach to quality risk management via describing how to conduct risk assessments and to manage the risks. This guidance provides the principles and some of the tools of quality risk management. This guide can also be used as a resource document that is independent of other ICH Quality documents. This guide leads to improvement in existing quality practices, requirements, standards, and guidelines within the pharmaceutical industry and regulatory framework.

•   The ICH Q10 describes a model for an effective pharmaceutical quality system that is based on International Standards Organization (ISO) quality concepts. This includes applicable GMP regulations and complements ICH Q8 and ICH Q9, and is applicable for a lifecycle of a product. This guideline focuses on regulating the quality management systems (QMS) into industry; where by any changes to manufacturing processes would be managed by appropriate change control procedures have been developed.

•   Although the initial focus of the science and risk based agenda was linked primarily to drug product, greater emphasis is now being placed on drug substance with the evolution of ICH Qll dedicated to the manufacture of drug raw materials. QbD provides unique opportunities to go beyond what was done in the past. The guideline focuses on development and manufacturing process of both chemical and biotechnological/biological drug substances and is intended to provide guidance in the scope of ICH Guideline Q6A and Q6B.

•   If the principles described in the ICH Q8, Q9 and Q10 guidance documents are implemented together in a holistic manner, then an effective system that emphasizes a harmonized science and risk-based approach to product development and maintenance is in place. This provides an even greater (quality) assurance that the patient will receive product that meets the CQA’s.

Some elements of QbD have been used for many years. For example, the use of design of experiment (DOE) in 1920’s as factorial designs were applied in agricultural science, and in the 1950’s when they were more widely used for industrial applications. Failure mode effect analysis (FMEA), a commonly used risk assessment tool, was developed by the United States Military to assess equipment and system failures. In the 1990’s, software was developed that combined risk assessment and DOE techniques.

The use of QbD strengthened in 2007,when FDA received up to 5000 supplements. It was actually eye-catching rise in the number of manufacturing supplements to applications of New Drug Applications (NDAs), Biological Licence Applications (BLAs) and Abbreviated New Drug Applications (ANDA’s). FDA recognized that there is an increase in delay of NDA or ANDA submissions by the firms. So large number of a supplemental application for every manufacturing change were received. In both original applications and supplements the data mainly focused was on chemistry. And the least attention was given on other important aspects of the manufacturing, such as engineering and product development.

1.3 REGULATORY ASPECTS OF QbD

Regulatory authorities, both the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) are placing more attention on the QbD component as a part of regulatory filing. QbD has become a crucial part of a drug development process. Regulatory bodies think that, by providing the quality at the design stage will benefit the organizations by reducing the defects or deviations at the later stages of product development. It also benefits the organizations on reducing the cycle time for the optimized product development.

FDA perspective

According to FDA,

•   Product quality and performance can be assured by designing efficient manufacturing processes.

•   Product and process specifications are based on a scientific understanding of how process factors affect product performance.

•   Risk-based regulatory approaches are for scientific understanding and control related process for product quality and performance.

•   Related regulatory policies and measures are modified to accommodate the real time scientific knowledge.

•   Quality Assurance is a continuous process.

Regulatory challenges and inspection

In a QbD concept, the regulatory burden is less because there are wider ranges and limits based on product and process understanding. Changes within these ranges and limits do not require prior approval. Traditionally, inspections have been conducted using the FDA sy stem-based approach and in accordance with Center for drug evaluation and research (CDER’s) Compliance Program Inspection of Licenced Biological Therapeutic Drug Products. But now query arises that how the inspection will take place in the present scenario where QbD is mandated. During pre-licence or preapproval inspection under a QbD concept, the FDA inspection team will assess the implementation and effectiveness of the process design as described in the application and whether knowledge and risk management have been transferred successfully from development to manufacturing. The inspection will evaluate the quality system and its effectiveness regarding consistent product quality, change in control procedures, process improvements, deviation management, and knowledge and risk management during the product lifecycle. Inspection of facility and equipment qualification and maintenance as well as raw material screening and supplier management will be same as it was performed previously . But design, testing, and monitoring programmes that demonstrate robustness and consistency would be