Current Regulatory Frameworks for Bioactive Inputs in Plant Systems Producing Pharmaceutically Important Compounds.

Plant cell, tissue, and organ cultures are increasingly used as controlled platforms for producing pharmaceutically important specialized metabolites. Their productivity can be improved through elicitors, plant biostimulant-like substances, microbial inputs, and nano-enabled delivery systems. However, the regulatory interpretation of these inputs is not determined only by their biological mechanism. It also depends on product composition, formulation, intended use, exposure scenario, and label claim. This review analyzes how elicitors, plant biostimulants, biofertilizer- and bioinput-related concepts, and nano-enabled inputs are positioned within selected regulatory frameworks in the European Union, United States, Canada, Brazil, India, China, and Mexico. The analysis shows that current frameworks increasingly emphasize product identity, efficacy substantiation, safety evidence, and labeling, but they remain fragmented for multifunctional materials that may simultaneously affect nutrient-related processes, abiotic stress tolerance, defense signaling, growth regulation, and specialized metabolism. Nano-enabled and encapsulated formulations create additional challenges because they can modify uptake, persistence, bioavailability, release behavior, residue profiles, and non-target exposure compared with conventional formulations. A clearer distinction is therefore needed between contained biotechnological use in plant biofactories and open-environment agricultural applications. Future regulatory development should move toward formulation-level assessment, claim-specific evidence, nanospecific characterization, traceability, and harmonized terminology to support innovation while ensuring safety, reproducibility, and regulatory clarity.