A nifedipine coground mixture with sodium deoxycholate. I. Colloidal particle formation and solid-state analysis.

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Physical Chemistry

Background:

• Sodium deoxycholate (DCNa) is a bile salt known for forming inclusion compounds with organic substances.
• Nifedipine is a poorly water-soluble drug, presenting formulation challenges.
• Developing amorphous forms of poorly soluble drugs can improve their bioavailability.

Purpose of the Study:

• To investigate the complex formulation of sodium deoxycholate (DCNa) with nifedipine using a cogrinding method.
• To characterize the solid-state properties of the nifedipine-DCNa coground mixture.
• To evaluate the particle size distribution of the nifedipine-DCNa complex in solution.

Main Methods:

• Cogrinding of nifedipine and DCNa using a vibration rod mill.
• Solid-state characterization via powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy.
• Particle size analysis using a laser diffraction particle size analyzer.

Main Results:

• Cogrinding nifedipine with DCNa (1:2 w/w) for 30 minutes resulted in a semitransparent colloidal solution with 90% of particles < 600 nm.
• PXRD and DSC showed the disappearance of nifedipine crystalline peaks and the appearance of a new exothermic peak, indicating amorphization.
• FTIR analysis suggested van der Waals interactions between nifedipine and DCNa molecules.

Conclusions:

• Cogrinding with DCNa is an effective method for producing amorphous nifedipine in the solid state.
• This technique facilitates the formation of colloidal drug particles in solution.
• The developed method offers a promising approach for formulating poorly water-soluble drugs like nifedipine.