Evaluation of solid dispersions of Clofazimine

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Materials Science

Background:

• Clofazimine (CLF) exhibits poor aqueous solubility, limiting its therapeutic efficacy.
• Developing advanced drug delivery systems is crucial for improving CLF bioavailability and patient outcomes.

Purpose of the Study:

• To formulate Clofazimine (CLF) as solid dispersions (SSD) using polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP).
• To enhance the aqueous solubility and dissolution rate of CLF.
• To evaluate the impact of different polymers, molecular weights, and drug:carrier ratios on CLF dissolution.

Main Methods:

• Solid dispersions prepared using solvent/melt methods with various PEG and PVP grades.
• Dissolution studies conducted using USP Type 2 apparatus in 0.1 N HCl.
• Saturation solubility, phase solubility, IR spectroscopy, and X-ray diffraction (XRD) used to characterize drug-carrier interactions and solid-state properties.

Main Results:

• Solid dispersion formulations significantly improved CLF dissolution rates compared to physical mixtures.
• Drug release improved with decreasing drug weight fraction.
• Polyvinyl pyrrolidone (PVP) solid dispersions exhibited superior drug release profiles over polyethylene glycol (PEG) systems.
• PVP 14,000 Da showed better performance than PVP 44,000 Da.
• All SSDs demonstrated improved saturation solubility of CLF.

Conclusions:

• Solid dispersion technology offers a promising approach to enhance Clofazimine's dissolution and solubility.
• PVP-based solid dispersions present a viable alternative to the current soft gelatin capsule formulation.
• Optimized CLF solid dispersions can lead to improved therapeutic advantages.