Formation of a New Regulatory Dossier for Marketing Authorization of a Generic Drug: A Review

1.1 Overview on Generic drugs

Generic drugs are medications that contain the same active ingredient, dosage form, strength, route of administration, quality, and performance characteristics as their brand-name counterparts. They become available after the original brand-name drug's patent and any exclusive marketing rights expire, allowing other manufacturers to produce identical versions (1). Regulatory agencies like the FDA (in the US) or EMA (in Europe) require generic drugs to demonstrate bioequivalence to the brand-name drug through rigorous testing, meaning they deliver the same amount of active ingredient into the bloodstream at the same rate and extent (2). This ensures generics are as safe and effective as the originals, though they often differ in inactive ingredients (such as color, shape, or fillers), which do not affect the drug's therapeutic action (3).

1.2 Importance of Generic Drugs

With the expiry of patents on originator drugs, generic versions have become essential for improving access to treatment. Generic drugs are bioequivalent to their reference products, offering the same quality, safety, and efficacy at significantly lower costs. In many markets, generics account for over 90% of prescriptions filled while representing only about 18–20% of total drug spending. This shift promotes competition, reduces healthcare expenditures, and enhances affordability, particularly in low- and middle-income countries (4). The primary advantage of generic drugs is their significantly lower cost—often 80-85% cheaper than brand-name versions—due to reduced research, development, and marketing expenses for manufacturers. This affordability improves access to essential medicines, reduces overall healthcare spending, and increases competition in the pharmaceutical market. Millions of prescriptions worldwide are filled with generics daily, and they account for the majority of dispensed drugs in many countries. While some patients perceive differences due to branding or minor variations in appearance, extensive evidence confirms that approved generics provide equivalent clinical outcomes when used as directed (5).

1.3 Overview on Dossier

A dossier (often spelled "dosier" in some contexts, likely a variant or typo) in pharmaceuticals refers to a regulatory dossier. It is a comprehensive compilation of documents and data submitted to regulatory authorities (e.g., FDA, EMA, CDSCO) to obtain marketing authorization (approval to sell) for a drug product, whether new or generic (6). The preparation of a regulatory dossier is a critical and systematic process that involves the compilation of scientific, technical, and administrative data related to a pharmaceutical product. A regulatory dossier serves as the primary document submitted to regulatory authorities for evaluation and approval. It contains comprehensive information on the drug substance, drug product, manufacturing process, quality control procedures, stability studies, and bioequivalence data. Any deficiencies or inconsistencies in the dossier may result in regulatory queries, delays in approval, or rejection of the application (7).

1.4 Regulatory Pathways for Generic Marketing Authorization

Marketing authorization for generics follows abbreviated pathways that rely on the safety and efficacy data of the reference listed drug (RLD), focusing primarily on pharmaceutical equivalence and bioequivalence (BE) (8). In the US, this is via the Abbreviated New Drug Application (ANDA); in the EU, Article 10 of Directive 2001/83/EC for generic/hybrid applications. Harmonization efforts through the International Council for Harmonisation (ICH) have standardized submissions using the Common Technical Document (CTD) format.

For generics, Modules 4 (non-clinical) and 5 (clinical) are abbreviated, often limited to BE studies, with emphasis on Module 3 (Quality) and Module 1 (regional administrative information) (9, 10).

II.  Regulatory Framework for Generic Drugs

The regulatory framework for generic drugs enables abbreviated approval pathways that rely on the established safety and efficacy of the reference listed drug (RLD) or innovator product, focusing primarily on demonstrating pharmaceutical equivalence and bioequivalence (BE). This approach, pioneered by the Hatch-Waxman Act in the US (1984), has been adopted globally to promote competition, reduce costs, and improve access to medicines.

2.1 International Harmonization: ICH Common Technical Document (CTD)

The International Council for Harmonisation (ICH) provides a standardized format for regulatory submissions through the Common Technical Document (CTD), divided into five modules.

• Module 1: Regional administrative information (e.g., application forms, labelling).
• Module 2: Summaries (quality overall summary, non-clinical and clinical overviews).
• Module 3: Quality (pharmaceutical development, manufacture, specifications).
• Module 4: Non-clinical study reports (abbreviated for generics).
• Module 5: Clinical study reports (primarily BE studies for generics).

For generics, Modules 4 and 5 are significantly reduced, with emphasis on Module 3 and BE data in Module 5. The electronic CTD (eCTD) is mandatory in many regions. Recent alignment includes ICH M13A (for quick-release oral forms), starting 2025, unifying BE setup, analysis, and standards for items like this medication's pills (11, 12).

2.2 United States: FDA Abbreviated New Drug Application (ANDA)

The US pathway is governed by the Drug Price Competition and Patent Term Restoration Act (Hatch-Waxman Act, 1984), allowing generics to reference the RLD without full preclinical/clinical data (13).

Key requirements:

• Pharmaceutical equivalence (same active ingredient, strength, dosage form, route).
• Bioequivalence (typically 90% CI for AUC and Cmax within 80–125%).
• GMP compliance and labelling similarity (14).

2.3 European Union: EMA Generic and Hybrid Applications

In the EU, generics fall under Article 10(1) of Directive 2001/83/EC (full generic: identical to reference), while hybrids (Article 10(3)) apply when differences (e.g., indications, strength) require additional data (15).

2.4 Global Access: WHO Prequalification Programme

For international procurement (e.g., UN agencies), the WHO Prequalification of Medicines Programme assesses generics for quality, safety, and efficacy, often for HIV, TB, malaria, and reproductive health, but expandable to essentials drugs. Generics may qualify if targeting global health programs (16).

2.5 Implications for Generic Medications

A drug with (high solubility/permeability), typically qualifies for straightforward BE with fasting studies and potential biowaivers. The harmonized CTD and ICH M13A facilitate multi-region submissions, reducing duplication while ensuring therapeutic equivalence to the RLD. This framework balances innovation incentives with affordable access globally (17, 18).

2.6 Indian Regulatory Framework for Generic Drugs

The regulatory framework for generic drugs in India is primarily governed by the Drugs and Cosmetics Act, 1940, along with the Drugs and Cosmetics Rules, 1945, and supplemented by the New Drugs and Clinical Trials Rules, 2019. The Central Drugs Standard Control Organization (CDSCO), under the Ministry of Health and Family Welfare, serves as the national regulatory authority responsible for approving drugs, including generics, while state licensing authorities handle manufacturing licenses for most generics. Unlike innovator (new) drugs, generic drugs—defined as formulations containing the same active pharmaceutical ingredient (API) in the same strength, dosage form, and route of administration as an already approved reference product—do not require full clinical trials. Instead, approval focuses on demonstrating pharmaceutical equivalence, quality, safety, and bioequivalence (BE) to the reference product, particularly for drugs approved in India for less than four years or those with narrow therapeutic index requirements (19). For most generic drug approvals, manufacturers submit applications to the State Licensing Authority (SLA) for manufacturing licenses or to CDSCO for certain categories, supported by data on chemistry, manufacturing, and controls (CMC), stability studies, and bioequivalence studies when mandated. Bioequivalence is a key requirement, especially following amendments that made BE studies compulsory for many generics to ensure they deliver the same therapeutic effect as the innovator product (typically within 80-125% acceptance criteria for key pharmacokinetic parameters). CDSCO guidelines on bioavailability and bioequivalence (BA/BE) studies align with international standards (e.g., ICH), and facilities must comply with Good Manufacturing Practices (GMP). This abbreviated pathway enables faster market entry, supporting India's position as a major global supplier of affordable generics while prioritizing patient safety through post-approval surveillance and quality testing (20). Challenges persist, including variations in enforcement between central and state levels, occasional quality concerns, and the need for stronger pharmacovigilance. Reforms under the New Drugs and Clinical Trials Rules, 2019, and ongoing CDSCO updates have aimed to streamline processes, enhance transparency via the SUGAM portal, and align more closely with global norms to boost export credibility and domestic confidence in generics. Overall, the framework promotes accessibility and competition while evolving to address quality assurance in one of the world's largest generic pharmaceutical markets (21, 22).

III. The Common Technical Document (CTD)

The Common Technical Document (CTD) is a harmonized international format developed by the International Council for Harmonisation (ICH) to standardize the submission of technical data for marketing authorization applications. Introduced in 2003, the CTD facilitates simultaneous submissions across ICH regions (EU, US, Japan, and others), reducing duplication and streamlining regulatory reviews. The CTD is organized into five modules, often visualized as a triangle or pyramid, with Module 1 at the top (region-specific) and Modules 2–5 forming the harmonized core.

3.1 Key Features of the CTD

• Paper or Electronic Submission: Most agencies now mandate the electronic CTD (eCTD), which uses XML backbone for lifecycle management, navigation, and validation.
• Latest Updates: As of January 2026, the core organization follows ICH M4(R4). A major revision, ICH M4Q(R2) (Quality module), reached Step 2b in mid-2025 and is under consultation (closed October 2025), with expected finalization in 2027. This revision enhances digitalization, granularity, and compatibility with modern technologies (e.g., AI/ML, advanced manufacturing) (23).

CTD Modules Overview: