Preparation and evaluation of andrographolide-loaded microemulsion

Area of Science:

• Pharmaceutics
• Drug Delivery Systems
• Natural Product Chemistry

Background:

• Andrographolide exhibits poor aqueous solubility and oral bioavailability, hindering its therapeutic potential.
• Effective drug delivery systems are crucial for overcoming the limitations of poorly soluble compounds like andrographolide.

Purpose of the Study:

• To formulate and characterize an andrographolide-loaded microemulsion to improve its solubility and oral bioavailability.
• To evaluate the stability, anti-inflammatory activity, pharmacokinetics, and oral toxicity of the developed microemulsion.

Main Methods:

• An oil-in-water (O/W) microemulsion was formulated using isopropyl myristate, Tween 80, alcohol, and water.
• Characterization included droplet size analysis, andrographolide solubilization capacity, and stability studies under various conditions.
• In vitro and in vivo studies assessed anti-inflammatory effects, pharmacokinetics, and acute oral toxicity compared to andrographolide tablets.

Main Results:

• The optimized O/W microemulsion achieved a mean droplet size of 15.9 nm and a high andrographolide solubilization capacity (8.02 mg/mL).
• The microemulsion exhibited excellent stability and significantly enhanced anti-inflammatory effects and oral bioavailability compared to conventional tablets.
• Acute oral toxicity studies revealed a very low toxicity profile for the andrographolide-loaded microemulsion.

Conclusions:

• Andrographolide-loaded microemulsion represents a promising advanced dosage form.
• This formulation effectively overcomes the solubility and bioavailability challenges of andrographolide.
• The enhanced therapeutic efficacy and safety profile suggest significant clinical potential.