3D-Printed Capsaicin-Loaded Injectable Implants for Targeted Delivery in Obese Patients

Area of Science:

• Pharmacology
• Biomaterials Science
• Drug Delivery Systems

Background:

• Obesity and hyperlipidemia are significant public health issues linked to metabolic disorders.
• Current treatments for obesity have limitations, including side effects and poor patient acceptance.
• Capsaicin, from chili peppers, has anti-obesity effects but suffers from low oral bioavailability.

Purpose of the Study:

• To develop and characterize 3D-printed capsaicin-loaded implants for sustained drug delivery.
• To evaluate the feasibility of using thermoplastic extrusion-based 3D printing for creating these implants.
• To assess the in vitro release profile, stability, and drug-polymer interactions of the capsaicin implants.

Main Methods:

• Utilized thermoplastic extrusion-based 3D printing to fabricate rod-shaped implants with capsaicin-loaded polycaprolactone.
• Investigated various drug loadings and infill densities.
• Characterized implants using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).
• Performed in vitro drug release studies and stability testing under accelerated conditions (40°C).
• Developed and validated a stability-indicating High-Performance Liquid Chromatography (HPLC) method.

Main Results:

• 3D-printed implants exhibited a smooth surface without visible capsaicin crystals.
• DSC analysis indicated no significant drug-polymer interactions.
• In vitro studies demonstrated a sustained biphasic release of capsaicin over three months (approximately 85% release).
• Release profiles were consistent across different drug loadings and infill densities.
• HPLC analysis confirmed the stability-indicating nature of the method.
• Implants remained stable for three months under accelerated conditions, showing no significant decrease in capsaicin assay.

Conclusions:

• 3D-printed capsaicin-loaded polycaprolactone implants provide a viable long-acting injectable formulation.
• This approach offers a potential site-specific delivery system for targeting adipose tissue in obese patients.
• The sustained release profile addresses the challenge of capsaicin's low oral bioavailability.