Fabrication of Phytosome with Enhanced Activity of Sonneratia alba: Formulation Modeling and in vivo Antimalarial Study

Introduction: Sonneratia alba extract exhibits antimalarial activity, mainly due to its secondary metabolites—naphthoquinones, flavonoids, tannins, and saponins—where naphthoquinone is the primary active component. However, its low bioavailability limits its effectiveness. To improve this, a phytosome-based vesicular system was proposed. This study focused on formulating a phytosome with S. alba and developing a predictive model to enhance its antimalarial activity.
Methods: Phytosomes were produced using antisolvent precipitation and optimized with 3-factor, 3-level Box-behnken model. Particle size, zeta potential, and entrapment efficiency were assessed. The optimized phytosomes were characterized by their physical properties and release profiles. Their antimalarial activity was tested in white BALB/c mice infected with Plasmodium berghei using Peter’s 4-day suppressive test.
Results: The optimal phytosome formulation used a phospholipid-to-extract ratio of 1:3, reflux temperature of 50°C, and a duration of 2.62 hours. The phytosomes had a particle size of 471.8 nm, a zeta potential of − 54.1 mV, and an entrapment efficiency (EE) of 82.4%. In contrast, the phytosome-fraction showed a particle size of 233.4 nm, a zeta potential of − 61.5 mV, and an EE of 87.08%. TEM analysis confirmed both had a spherical shape. In vitro release rates at 24 hours were 86.2 for the phytosome-extract and 95.9% for the phytosome-fraction, compared to 46.9% and 37.7% for the extract and fraction alone. Overall, the phytosome formulation demonstrated good stability. The actual experimental values closely matched the predicted values from the Box–Behnken model, indicating a high degree of accuracy in the model. Additionally, the phytosomes exhibited significantly greater antimalarial activity than the S. alba extract and fraction alone.
Conclusion: The findings indicated that the vesicular formulation in phytosomes can enhance the antimalarial activity of S. alba extract and fraction.

Keywords: antimalarial S.alba, phytosome, box-behnken, extract, fraction