Efavirenz Dissolution Enhancement IV-Antisolvent Nanocrystallization by Sonication, Physical Stability, and...

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Nanotechnology

Background:

• Efavirenz (EFV), a key HIV medication, exhibits poor water solubility, limiting its oral bioavailability.
• Particle nanonization, specifically nanocrystallization, offers a strategy to improve drug dissolution and absorption.
• Developing stable efavirenz nanocrystals requires careful selection of stabilizers and optimization of process parameters.

Purpose of the Study:

• To develop and characterize efavirenz nanocrystals using a sonication-assisted method.
• To evaluate the impact of different polymer stabilizers (HPMC, PVP) and their concentrations on nanocrystal properties.
• To assess the dissolution enhancement and physical stability of the prepared efavirenz nanosuspensions and dried powders.

Main Methods:

• Efavirenz (EFV) was dissolved in methanol and added to aqueous solutions of HPMC and PVP stabilizers under sonication.
• Particle size, zeta potential, and physical stability (sedimentation, particle growth) were analyzed using dynamic light scattering and Turbiscan™.
• Freeze-drying was employed to obtain EFV nanocrystal powder, which was characterized by SEM and dissolution testing.

Main Results:

• Hydroxymethylpropyl cellulose (HPMC) and polyvinylpyrrolidone (PVP) were identified as suitable stabilizers for efavirenz (EFV) nanocrystals.
• Nanosuspensions exhibited nanosized particles and adequate zeta potential, but instability (sedimentation, growth) was observed at low polymer concentrations (20%).
• Scanning electron microscopy (SEM) revealed film formation at 40% polymer concentration and particle aggregation at lower concentrations. Dissolution rates were significantly higher than raw EFV, increasing with lower polymer concentrations.

Conclusions:

• Nanocrystallization is an effective technique to enhance the dissolution of poorly soluble efavirenz (EFV).
• The choice of polymer stabilizer (HPMC, PVP) and its concentration significantly impacts nanocrystal stability and dissolution.
• Optimizing polymer concentration is essential to balance particle size, prevent aggregation, and achieve improved bioavailability for efavirenz-based HIV therapies.