Evaluation of controlled-release polar lipid microparticles

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Materials Science

Background:

• Poorly soluble drugs like felodipine present challenges in achieving effective controlled release.
• Erodable lipophilic excipients are explored for formulating solid dispersions to improve drug dissolution.

Purpose of the Study:

• To prepare controlled-release felodipine tablets using spray chilling and various erodable lipophilic excipients.
• To investigate the influence of microparticle characteristics and tablet properties on felodipine dissolution rate.

Main Methods:

• Spray chilling was employed to create solid dispersion microparticles of felodipine and excipients.
• Characterization involved Fourier transform infrared spectroscopy, hot-stage microscopy, scanning electron microscopy, and image analysis.
• Tablet disintegration and drug release studies were conducted.

Main Results:

• Spherical microparticles with a median diameter of 25-35 microm were produced.
• Hydrogen bonds formed between felodipine's amine/carbonyl groups and carriers.
• Tablet disintegration ease and felodipine crystallinity were more critical to dissolution rate than matrix lipophilicity.
• Slowest felodipine release occurred from the least lipophilic tablets.

Conclusions:

• Controlled-release felodipine tablets can be formulated using spray chilling and erodable lipophilic excipients.
• Tablet disintegration and drug crystallinity are key factors controlling felodipine release, overriding matrix lipophilicity.
• This formulation approach offers potential for optimizing the delivery of poorly soluble drugs.