A pragmatic regulatory approach for complex generics through the U.S. FDA 505(j) or 505(b)(2) approval pathways

Nanosimilars: A Scientific or A Regulatory Debate?

The paper highlights the necessity for a robust regulatory framework for assessing nanomedicines and their off-patent counterparts, termed as nanosimilar, which could be considered as 'similar' to the prototype nanomedicine,based on essential criteria describing the 'similarity'. The term 'similarity' should be focused on criteria that describe nanocarriers, encompassing their physicochemical, thermodynamic, morphological, and biological properties, including surface interactions and pharmacokinetics. Nanocarriers can be regarded as advanced self-assembled excipients (ASAEs) due to their complexity and chaotic behavior and should be evaluated by using essential criteria in order for off-patent nanomedicines be termed as nanosimilars, from a regulatory perspective. Collaboration between the pharmaceutical industry, regulatory bodies, and artificial intelligence (AI) startups is pivotal for the precise characterization and approval processes for nanomedicines and nanosimilars and embracing innovative tools and terminology facilitates the development of a sustainable regulatory framework, ensuring safety and efficacy. This crucial shift toward precision R&D practices addresses the complexity inherent in nanocarriers, paving the way for therapeutic advancements with economic benefits.

Applying a risk assessment guided evaluation for verifying comprehensive two-dimensional gas chromatography to analyse complex pharmaceuticals

The reliability of analytical results is critical and indispensable when applied in regulated environments such as the pharmaceutical industry. Therefore, analytical workflows must be validated. However, validation guidelines are often designed for quantitative targeted analysis and rarely apply to qualitative untargeted approaches. In this study, we employ a risk assessment approach to identify critical parameters which might influence the qualitative results derived by online derivatisation - comprehensive two-dimensional gas chromatography coupled to a high-resolution time-of-flight mass spectrometer (GC × GC-HR-ToF-MS) for the analysis of the active pharmaceutical ingredient (API) sodium bituminosulfonate (SBS). To show the complexity and feasibility of such an approach, we focus on investigating three potential risk factors: sample preparation, vapourability, and the thermal stability of sulfonates. Through the individual evaluation of these potential risk factors due to the application of sample preparation approaches and thermal gravimetric analysis (TGA), we demonstrate the high derivatisation efficiency and repeatability of the online derivatisation method and confirm the absence of derivatisation-induced side reactions. In addition, we also show the potential thermal instability of an incompletely derivatised API. To address the limitation of these individual assessments, we applied a holistic evaluation step with negative electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry (ESI( -) FT-ICR MS) as an orthogonal technique. This confirms that most of the API is detected via the presented GC-based method. Thereby, we demonstrated the practical feasibility of the risk assessment-based approach to ensure the validity of the qualitative data for a complex untargeted method.

Regulatory considerations for generic products of non-biological complex drugs

The Non-Biological Complex Drug (NBCD) Working Group defines an NBCD as "a medicinal product, not being a biological medicine, where the active substance is not a homo-molecular structure, but consists of different (closely related and often nanoparticulate) structures that cannot be isolated and fully quantitated, characterized and/or described by physicochemical analytical means". There are concerns about the potential clinical differences between the follow-on versions and the originator products and within the individual follow-on versions. In the present study, we compare the regulatory requirements for developing generic products of NBCDs in the European Union (EU) and the United States (US). The NBCDs investigated included nanoparticle albumin-bound paclitaxel (nab-paclitaxel) injections, liposomal injections, glatiramer acetate injections, iron carbohydrate complexes, and sevelamer oral dosage forms. The demonstration of pharmaceutical comparability between the generic products and the reference products through comprehensive characterization is emphasized for all product categories investigated. However, the approval pathways and detailed requirements in terms of non-clinical and clinical aspects may differ. The general guidelines in combination with product-specific guidelines are considered effective in conveying regulatory considerations. While regulatory uncertainties still prevail, it is anticipated that through the pilot program established by the European Medicines Agency (EMA) and the FDA, harmonization of the regulatory requirements will be achieved, thereby facilitating the development of follow-on versions of NBCDs.

Long-acting intrauterine systems: Recent advances, current challenges, and future opportunities

Levonorgestrel intrauterine systems (LNG-IUSs) are complex drug-device combination products designed to release a hormonal contraceptive drug for up to 7 years. These drug delivery systems offers a great promise as a modern method of long-acting reversible contraceptives (LARCs) to improve women's health. Unfortunately, there are some scientific challenges associated with the development of these products which are among the major reasons contributing to the availability of relatively few IUS products on the market. This review summarizes the formulation considerations (drug and excipient attributes), manufacturing methods, advances in characterization and in vitro drug release testing of IUSs, as well as factors influencing drug release from IUSs. A critical discussion on the major challenges to IUS product development is presented. Specifically, insights on bioequivalence evaluation, in vitro-in vivo correlation (IVIVC) establishment, and regulatory challenges are detailed. Lastly, methodological tools to overcome some of these hurdles to product development are proposed. The knowledge furnished through this review will be helpful towards obtaining better product understanding. Such understanding will facilitate the development of these complex drug products, as well as their regulatory approval process.

Analysis of complex drugs by comprehensive two-dimensional gas chromatography and high-resolution mass spectrometry: detailed chemical description of the active pharmaceutical ingredient sodium bituminosulfonate and its process intermediates

The European pharmacopeia provides analytical methods for the chemical characterization of active pharmaceutical ingredients (APIs). However, the complexity of some APIs exceeds the limitations of the currently prevailing physicochemical methods. Sodium bituminosulfonate (SBS) is described by the collection of key parameters of generalizing criteria such as dry matter, sulfur and sodium content, and neutrality, but techniques to unravel the complexity on a molecular level are lacking. We present a study based on online derivatization with tetramethylammonium hydroxide in combination with comprehensive two-dimensional gas chromatography coupled to an electron ionization high-resolution time-of-flight mass spectrometer (GC × GC-HR-ToF–MS) for the chemical description of SBS as well as its process intermediates. The application of GC × GC allowed the comprehensive description of the chemical components in the API and the process intermediates for the first time. Furthermore, it was possible to classify peaks regarding their elemental and structural composition based on accurate mass information, elution behavior, and mass fragmentation pattern. This work demonstrates not only the general applicability, advantages but also limitations of GC × GC for the characterization of APIs for complex drugs.

Graphical Abstract

Regulatory Science Approach in Pharmaceutical Development of Follow-On Versions of Non-Biological Complex Drug Products

Scientific and technological breakthroughs in the field of Nanotechnology have been a driving force throughout the development and approval of Non-Biological Complex Drugs (NBCDs). However, the fast-growing expansion of NBCDs and the emergence of their follow-on versions have brought with them several scientific, technological, and regulatory challenges. The definition of NBCDs is still not officially recognized by the regulatory authorities, and there is no dedicated regulatory pathway addressing the particular features of NBCDs and their follow-on versions. The lack of clear and consistent regulatory guidance documents in this field, as well as, the inconsistency across different regulatory agencies, impact negatively on the acceptance and enormous potential of these drug products. Patient access to high-quality NBCDs follow-on versions may be compromised by regulatory uncertainty resulting from the use of different regulatory approaches across the globe, as well as within the same class of products. Accordingly, there is a real need to develop a specific regulatory pathway compliant with the complexity of NBCDs and their follow-on versions or, alternatively, make better use of available regulatory pathways. The main goal of the review is to deeply investigate and provide a critical overview of the regulatory landscape of NBCDs and follow-on versions currently adopted by the regulatory authorities. The dissemination of knowledge and discussion in this field can contribute to clarifying regulations, policies, and regulatory approaches to complex generics, thereby filling regulatory and scientific gaps in the establishment of therapeutic equivalence.