Generic parenteral products: Regulatory, safety, and toxicological facets

Abstract

A fundamental requirement for generic parenteral drug products is ensuring patient safety and therapeutic equivalence to reference products. Injectable formulations bypass physiological barriers such as first-pass metabolism, increasing the risk of severe adverse effects, including pyrogenic reactions, embolism, and immunogenic responses. Therefore, stringent regulatory oversight of sterility assurance, impurity control, and excipient safety is essential to prevent systemic toxicity and ensure product quality. This review critically evaluates the regulatory and toxicological frameworks governing Abbreviated New Drug Applications (ANDAs) for generic parenterals across major regulatory agencies. Current expectations emphasize robust toxicological justification for excipient changes and unidentified contaminants, while deficiencies in sterility validation and extractables and leachables (E&L) management remain key causes of ANDA rejection. This review provides a timely perspective on EU GMP Annex 1 (2023) and rising scrutiny of sterile manufacturing and impurity risks, presenting an integrated regulatory–toxicological framework linking issues in generic sterile products to exposure pathways and toxicological outcomes. The review emphasizes the role of QbD and real-time release testing in strengthening risk-based control strategies, while identifying key gaps in toxicological tools such as E&L and TTC assessments.