ABSTRACT:
Phytosomes (phyto-phospholipid complexes) are nanoscale lipid vesicles engineered to dramatically improve the bioavailability and stability of herbal phytochemicals. Formed by complexing plant extracts with phospholipids (typically phosphatidylcholine) in an organic solvent, phytosomes create amphiphilic complexes in which the hydrophilic phytoconstituent head is bound to the polar phospholipid headgroup while the lipid tails form a protective envelope. This structure allows encapsulated actives to traverse lipid membranes and resist degradation, resulting in much higher absorption and efficacy than uncomplexed extracts. Common preparation methods (e.g. solvent evaporation, anti-solvent precipitation, lyophilization) yield particles on the order of tens to a few hundred nanometers, with high drug-loading efficiency and stability. Such nanocarriers enable delivery of both water-soluble and lipid-soluble plant compounds, often permitting lower dosages due to enhanced uptake. This review covers phytosome history, complexation mechanism (hydrogen-bonding of polar groups), characterization techniques (NMR/FTIR confirmation of complexation, particle size/zeta analysis), and formulation into dosage forms (softgel capsules, tablets, topical gels). Marketed phytosome formulations (e.g. silybin–phospholipid, ginkgo, green tea complexes) show substantially improved pharmacokinetics and therapeutic outcomes in indications like liver protection, cardiovascular support and inflammation compared to conventional extracts. In summary, phytosome vesicles represent an innovative herbal drug-delivery platform that overcomes solubility and permeability barriers to substantially boost the efficacy of plant-derived medicines.