Spray-dried gastroretentive floating microparticles: preparation and in vitro evaluation

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Floating microparticles offer prolonged gastric residence time for improved drug absorption.
• Spray drying is an efficient technique for microparticle fabrication, but solvent selection is critical.

Purpose of the Study:

• To develop and characterize solvent-free floating microparticles using spray drying.
• To evaluate the impact of polymer composition and drug-polymer ratio on microparticle properties and drug release.
• To confirm drug-excipient compatibility and assess the morphology of the microparticles.

Main Methods:

• Full factorial design to optimize drug: polymer and Eudragit RS 100: Eudragit RL 100 ratios.
• Spray drying technique for microparticle preparation.
• Evaluation of buoyancy, drug release kinetics (using paddle apparatus, pH 1.2 buffer), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM).

Main Results:

• All formulations exhibited excellent buoyancy (>90% floating for 12 hours).
• Polymer amount significantly influenced entrapment efficiency (P<0.05).
• Eudragit RS 100: Eudragit RL 100 ratio affected the time for maximum drug release (P<0.05).
• Optimized formula showed anomalous transport (n=0.7042) indicating non-Fickian diffusion.
• FTIR and DSC confirmed drug-excipient compatibility.
• Microparticles were spherical, non-aggregated, with sizes ranging from 21-30 μM.

Conclusions:

• Spray drying is a viable solvent-free method for producing buoyant microparticles.
• The developed microparticles show potential for controlled drug delivery applications.
• Optimized Eudragit ratios enable tunable drug release profiles.