Supercritical fluid extraction of bioactive antioxidants for pharmaceutical formulation: quality attributes, regulatory considerations, and translational constraints
摘要
Supercritical fluid extraction (SFE) has gained attention as a tunable extraction platform for obtaining antioxidant-rich fractions with potential relevance to pharmaceutical and nutraceutical formulation. Carbon dioxide (CO₂), alone or combined with food- or pharmaceutically acceptable modifiers such as ethanol, allows extraction selectivity to be adjusted through pressure, temperature, modifier concentration, and matrix preparation. Compared with solvent-intensive methods, SFE may reduce residual organic-solvent burden and thermal exposure, which is relevant for heat-sensitive compounds and subsequent formulation development. However, its performance is strongly dependent on compound polarity, plant matrix structure, moisture content, particle size, and process scale. Lipophilic antioxidants such as carotenoids and tocopherols are generally more compatible with CO₂-based extraction, whereas more polar phenolic compounds often require modifier-assisted conditions. SFE-derived extracts have been explored in lipid-based systems, particles, and porous carriers to improve stability, handling, and bioavailability-oriented delivery, but extraction efficiency and in vitro antioxidant activity should not be interpreted as direct evidence of therapeutic efficacy. For pharmaceutical translation, additional attention is needed to marker-compound standardization, batch-to-batch variability, residual-solvent control, pre-formulation attributes, pharmacokinetic relevance, toxicity, and dose justification. Recent developments in process monitoring, design-of-experiments, and data-assisted optimization may support more reproducible SFE processes, although their industrial and regulatory implementation remains limited. This review therefore examines SFE not as a universal solution for antioxidant-based drug development, but as a formulation-relevant extraction and fractionation approach whose value depends on compound class, matrix properties, quality requirements, and translational evidence.
Graphical Abstract