Comparative study of preparation and characterization of enteric and enhanced release omeprazole microparticles

This article deals with study of the comparison of two different methods. Firstly, the preparation of microparticles of omeprazole using spray drying technique and then filling hard gelatin capsules coated with enteric polymer with these particles. The other method is the preparation of enteric microspheres by emulsification/solvent method. Omeprazole microparticles were prepared by spray drying technique using hydroxypropyl-β-cyclodextrin as a carrier. A phase solubility study of the complex was attempted. Physicochemical properties of the prepared microparticles were investigated using differential scanning calorimetry and powder X-ray diffractometry. Dissolution rate was determined and compared to the drug. The morphology was studied using a scanning electron microscope. Omeprazole transformed from the crystalline state to the amorphous state as confirmed by the disappearance of its melting peak and the characteristics of the crystalline peaks. Omeprazole dissolution rate was enhanced significantly from its spray dried microparticles as compared to the corresponding drug alone (p < 0.05). In acidic medium, the release of drug from enteric coated capsules was not detectable, while its release in phosphate buffer (pH 7.4) depends on the amount of the hydrophilic carrier. Omeprazole microspheres were prepared by emulsification/solvent technique using Eudargit S100 as enteric polymers. The prepared microspheres were characterized by DSC and a scanning electron microscope. The dissolution of microspheres was also attempted. The results showed that, the prepared microspheres are spherical in shape. DSC results showed that the drug dispersed homogenously in the polymer. Also, the dissolution of drug depends on the ratio of the drug:Eudargit S100.