IntroductionStress testing has long been recognized as an important part of the drug development process. Efforts by the International Conference on Harmonization (ICH) with regard to impurities (1,2,3,4) and stability (5,6,7) have brought an increased regulatory ...Chapter Opening | Online Chapter | Chapter PDF (56 KB) | PDF Plus (61 KB)
Chapter 2
Stress testing: A predictive toolAs described in chapter 1, stress testing is the main tool that is used to predict stability-related problems, develop analytical methods, and identify degradation products and pathways. Stability-related issues can affect many areas, including the ...Chapter Opening | Online Chapter | Chapter PDF (1052 KB) | PDF Plus (1073 KB)
Chapter 3
Stress testing: The chemistry of drug degradationIn this chapter, we will examine the major mechanisms of chemical decomposition of pharmaceuticals in the context of common functional groups. The major mechanisms of chemical decomposition of pharmaceuticals include hydrolysis/dehydration, oxidation, ...Chapter Opening | Online Chapter | Chapter PDF (8541 KB) | PDF Plus (8572 KB)
Chapter 4
Stress testing: Analytical considerationsAlthough there are some guidelines for stress testing given in the International Conference on Harmonization (ICH) guideline on the stability testing of drug substances and drug products, the guidance given is very general and not particularly useful for ...Chapter Opening | Online Chapter | Chapter PDF (554 KB) | PDF Plus (556 KB)
Chapter 5
Stress testing: Relation to the development timelineAs has been discussed elsewhere (1,2), for a novel drug candidate that progresses from discovery through preclinical and clinical stages of development and eventually to the market, stress testing is not a “one-time” event. Instead, stress testing is ...Chapter Opening | Online Chapter | Chapter PDF (146 KB) | PDF Plus (149 KB)
Chapter 6
Oxidative susceptibility testingWater and molecular oxygen (dioxygen) are the two ubiquitous molecules that most frequently affect the stability of a drug substance. Though acids and bases are the main catalysts that control the hydrolytic behavior of organic compounds, they are not the ...Chapter Opening | Online Chapter | Chapter PDF (1273 KB) | PDF Plus (1284 KB)
Chapter 7
Photostability stress testingThe problem of photostability of drugs has received relatively little attention in the pharmaceutical industry. Furthermore, until a decade ago, the degradation studies carried out involved variable protocols, every single issue being confronted in a ...Chapter Opening | Online Chapter | Chapter PDF (3281 KB) | PDF Plus (3295 KB)
Chapter 8
Practical aspects of conducting photostability stress testingThe photostability of active pharmaceutical ingredients (API) and drug products (DP) may impact shelf life, handling, packaging, and even photosafety of the product (e.g., phototoxicity and photogenotoxicity). Hence, photostress testing is an important ...Chapter Opening | Online Chapter | Chapter PDF (827 KB) | PDF Plus (830 KB)
Chapter 9
Role of “mass balance” in pharmaceutical stress testingThe assessment of degradation in pharmaceutical products involves two aspects of analytical measurement. First, a selective analytical method must be available for accurate assay of the parent drug compound, in order to correctly measure any loss. Second, ...Chapter Opening | Online Chapter | Chapter PDF (655 KB) | PDF Plus (661 KB)
Chapter 10
Solid-state pharmaceutical development: Ensuring stability through salt and polymorph screeningPhysical and chemical properties of an active pharmaceutical ingredient that affect the performance of solid oral dosage forms, such as chemical stability, mechanical properties, hygroscopicity, solubility and dissolution rate, are strongly influenced by ...Chapter Opening | Online Chapter | Chapter PDF (894 KB) | PDF Plus (941 KB)
Chapter 11
Solid-state excipient compatibility testingSelection of appropriate excipients for formulation of drug substances is vitally important in ensuring final product stability and efficacy (1). As formulation scientists, it is imperative that we develop pharmaceutical products that have acceptable ...Chapter Opening | Online Chapter | Chapter PDF (1295 KB) | PDF Plus (1343 KB)
Chapter 12
Small molecule parenteral drugs: Practical aspects of stress testingParenteral drugs comprise a diverse class of medications that are not administered via the enteral (gastrointestinal) route. Parenteral drugs are typically targeted to provide systemic or localized exposure of the drug which may be achieved via injection, ...Chapter Opening | Online Chapter | Chapter PDF (709 KB) | PDF Plus (712 KB)
Chapter 13
Stability considerations in development of freeze-dried pharmaceuticalsCritical quality attributes of freeze-dried injectable pharmaceuticals include sterility, freedom from pyrogens, and freedom from extraneous particulate matter. These attributes are achieved by appropriate processing conditions. In addition, these ...Chapter Opening | Online Chapter | Chapter PDF (1300 KB) | PDF Plus (1328 KB)
Chapter 14
Stress testing of therapeutic monoclonal antibodiesOver the past 30 years, tremendous progress in the field of biotechnology has produced over a hundred protein- and peptide-based pharmaceutical products approved for a broad spectrum of diseases (1). Current industry trends for molecules entering clinical ...Chapter Opening | Online Chapter | Chapter PDF (351 KB) | PDF Plus (385 KB)
Chapter 15
Stress testing of oligonucleotidesThe specific binding of synthetic oligonucleotides to cellular RNA through Watson–Crick base pairing can result in modulation of gene expression. This is the basis of the antisense concept, the therapeutic potential of which was first enunciated over 30 ...Chapter Opening | Online Chapter | Chapter PDF (3999 KB) | PDF Plus (4026 KB)
Chapter 16
Stress testing to determine liposome degradation mechanismsLiposomes represent one of the first “nanoscale” technologies used in drug delivery, and continue to be a source of innovative solutions because of the vast variety of lipid compositions, size, charge, and other characteristics that can be tailored to a ...Chapter Opening | Online Chapter | Chapter PDF (468 KB) | PDF Plus (498 KB)
Chapter 17
Stress testing of combination therapiesThis chapter will focus on stress testing of drug products that contain more than one active pharmaceutical ingredient (API). These dosage forms are often referred to as combination therapies (1), a special case of combination products (2) which usually ...Chapter Opening | Online Chapter | Chapter PDF (172 KB) | PDF Plus (181 KB)
Chapter 18
Rapid stress stability studies for evaluation of manufacturing changes, materials from multiple sources, and stability- indicating methodsFrequently, time is of the essence. It is necessary to evaluate, in a short time span, the stability of a product change, and here, the design of stress conditions which will accelerate decomposition in a meaningful way is necessary. This is a difficult ...Chapter Opening | Online Chapter | Chapter PDF (2121 KB) | PDF Plus (2136 KB)
Chapter 19
Stress testing as a predictive tool for the assessment of potential genotoxic degradantsStrategies for dealing with genotoxic impurities (GTIs) or potential genotoxic impurities (PGIs) arising from drug synthesis have received considerable attention in the literature (1–6). In contrast to process impurities, genotoxic degradants have ...Chapter Opening | Online Chapter | Chapter PDF (2066 KB) | PDF Plus (2070 KB)
Chapter 20
The power of computational chemistry to leverage stress testing of pharmaceuticalsIt is a fundamental tenet of chemistry that the structural formula of any compound contains coded within it all that compound’s chemical, physical and biological properties. (From Ref. 1) Chapter Opening | Online Chapter | Chapter PDF (917 KB) | PDF Plus (943 KB)
Chapter 21
Automation in conducting stress testing and excipient compatibility studiesPharmaceutical and biotechnology companies are placing increasing pressure on their development to complete more work with less resources. These companies want to identify and solve issues with compounds at an earlier stage to minimize development costs ...Chapter Opening | Online Chapter | Chapter PDF (1731 KB) | PDF Plus (1734 KB)
Chapter 22
Use of isothermal microcalorimetry in stress testingIsothermal microcalorimetry (IMC) offers an attractive approach to stress testing because its measured parameter (heat change) is a near universal accompaniment to chemical or physical change. It is also nondiscriminating in terms of sample physical form (...Chapter Opening | Online Chapter | Chapter PDF (908 KB) | PDF Plus (922 KB)
Chapter 23
Temperature excursions during shipment and storageStress testing both on the drug substance and drug product complements the formal stability studies for registration and the knowledge gained from GMP maintenance studies (on-going stability studies). All data generated during development through to the ...Chapter Opening | Online Chapter | Chapter PDF (461 KB) | PDF Plus (463 KB)
Chapter 24
Stress testing: Frequently asked questionsThere are many potential problems and questions that the scientific researcher may encounter when attempting to design and carry out a stress-testing study for a pharmaceutical compound. This chapter is intended to address some of the more frequently ...Chapter Opening | Online Chapter | Chapter PDF (74 KB) | PDF Plus (77 KB)