Plectranthus madagascariensis phytosomes: formulation optimization

Medicinal plants have been a reliable source of bioactive natural products with potential pharmaceutical applications. The delivery of those bioactive agents into nanosystems is considered a promising strategy for the optimization of their pharmacologic effects. This work describes the preparation of phytosomes containing a bioactive extract from Plectranthus madagascariensis and optimization of the preparation method. Different formulations and process parameters were studied. It was observed that smaller and more uniform particles were obtained using acetone as solvent, a reaction time of two hours, and the addition of 2.5% molar concentration of cholesterol. The optimally prepared phytosomes had a diameter of 191.3 ± 75.3 nm with a polydispersity index of 0.243 ± 0.18, and a spherical shape with amorphous appearance. These nanosystems were able to encapsulate 92.8% of the extract, as evaluated by HPLC, relative to 7α,6β-dihydroxyroyleanona, the main extract component. This study suggests a future application of those phytosomes in the delivery of bioactive agents with therapeutic interest.