PREPARATION AND EVALUATION OF EXTENDED-RELEASE MICROSPHERES OF QUETIAPINE FUMARATE

The objective of present study was to develop extended release microspheres of quetiapine fumarate using Eudragit RS 100 and Eudragit RL100 to reduce the dosing frequency. The quetiapine fumarate-loaded Eudragit microspheres were formulated by a solvent evaporation method. A 3² factorial design was employed to study the effect of concentration of sodium lauryl sulfate (SLS) and drug: polymer ratio on percentage yield, percentage entrapment efficiency, particle size, and % in-vitro drug release at 10 h. Drug excipients compatibility study by DSC showed no interaction between drug and excipients. The entrapment efficiency was found to be 40.56 ±1.32  % to 72.66 ±2.13  %, and the particle size range was 165±3.51 µm to 243±3.05 µm. In-vitro drug release of quetiapine fumarate microspheres showed a sustained release up to 24 h. Concentration of SLS and drug: polymer ratio had significant effect on % yield, % entrapment efficiency, particle size and % in-vitro drug release. From all parameters and experimental design evaluation it was concluded that drug release rate decreased with an increase the drug: polymer ratio and a decrease in the amount of SLS. The scanning electron microscopy (SEM) study observed that microspheres were spherical and fairly smooth surfaces. The in-vitro release kinetics revealed Korsmeyer -Peppas model is followed, and drug release is by fickian diffusion.