Effect of antioxidants on captopril floating matrices

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Materials Science

Background:

• Captopril controlled release formulation stability is a persistent challenge.
• Floating matrices offer potential for sustained drug release.
• Optimizing formulation parameters is crucial for effective drug delivery.

Purpose of the Study:

• To investigate the impact of antioxidant load, sodium bicarbonate, and compaction pressure on captopril floating matrix stability and drug release.
• To understand how formulation variables influence matrix properties like density, hydration, and porosity.
• To optimize captopril release profiles from sustained-release floating dosage forms.

Main Methods:

• Fabrication of floating matrices with varying ascorbic acid (antioxidant) levels, sodium bicarbonate proportions, and compaction pressures (55 MPa vs. 165 MPa).
• Evaluation of matrix density, floating behavior, hydration volume, and drug release kinetics in a dissolution medium.
• Analysis of the influence of compaction pressure and excipient composition on matrix structure and drug diffusion.

Main Results:

• Matrices compacted at 55 MPa exhibited lower density and floated readily; those at 165 MPa required sodium bicarbonate for flotation.
• Increased compaction pressure reduced matrix porosity, hydration volume, and drug transport, prolonging drug release time.
• Higher ascorbic acid content increased hydration and drug release; sodium ascorbate and sodium bicarbonate addition accelerated release by generating CO2 bubbles.

Conclusions:

• Compaction pressure significantly influences the physical properties and floating capability of captopril matrices.
• Antioxidant type and proportion, along with sodium bicarbonate, modulate hydration, matrix integrity, and captopril release rates.
• Formulation adjustments offer a pathway to control captopril's sustained release from floating matrices, addressing stability challenges.