Formulation, Characterization, and Evaluation of β-Cyclodextrin Functionalized Hypericin Loaded Nanocarriers

Area of Science:

• Pharmaceutical Sciences
• Neuroscience
• Natural Products Chemistry

Background:

• St. John's wort is a traditional remedy for mild to moderate depression.
• Hypericin, a key compound in St. John's wort, exhibits antidepressant properties.
• Current treatments for depression often have side effects, necessitating alternative therapies.

Purpose of the Study:

• To formulate an optimized nanoemulsion (O/W) of hypericin for enhanced brain delivery.
• To evaluate the physicochemical properties and stability of the hypericin nanoemulsion.
• To assess the antidepressant efficacy of the nanoemulsion in vivo.

Main Methods:

• Nanoemulsion preparation using homogenization with Tween-80, Span-80, β-cyclodextrin, ethanol, and eucalyptus oil.
• Physicochemical characterization including globule size, zeta potential, pH, viscosity, and refractive index.
• Stability assessment through centrifugation and freeze-thaw cycles.
• In vitro, ex vivo drug release and permeation studies.
• In vivo behavioral tests (open field, elevated plus maze, tail suspension) to evaluate antidepressant activity.

Main Results:

• Globular nanosized structures with good consistency were confirmed by morphological and zeta analyses.
• Formulation F2 (0.125 mL oil, 1.25 mL aqueous, 8% β-cyclodextrin) exhibited optimal characteristics (pH 5.7, 5.35 cP viscosity, 148.8 nm size, -10.8 zeta potential).
• High drug release (71.75%) and permeation (76% in vitro, 75.07% ex vivo) were observed, with formulation F2 showing the best performance.
• In vivo studies indicated significant antidepressant effects comparable to commercial treatments.

Conclusions:

• The developed hypericin nanoemulsion is stable and suitable for nasal delivery.
• The nanoemulsion formulation demonstrates promising antidepressant efficacy.
• Hypericin nanoemulsion represents a viable natural alternative to synthetic antidepressant medications.