The Effect of Carrier Matrix and the Method of Preparing Solid Dispersion on Physical State and Solubility of Ibuprofen

Abstract

The poor solubility of a drug substance is one of the factors which are responsible for poor dissolution and bioavailabity. To enhance the solubility of Ibuprofen using different techniques, and to investigate the effect of carrier matrixes and methods of preparing solid dispersion on physical state and solubility of Ibuprofen. Fusion method, solvent evaporation and effervescence assisted fusion methods were used to prepare solid dispersions of ibuprofen (IBU). Mannitol, polyethylene-glycol-6000, urea, microcrystalline cellulose, calcium carbonate, sugar spheres, sodium chloride, magnesium oxide, titanium dioxide, citric acid, hydroxypropyl-β-cyclodextrin and β-cyclodextrin were used as carrier matrix. Solid dispersions were characterized using scanning electron microscopy and Differential Scanning Calorimetry (DSC). The solubility of IBU powder and its solid dispersions were investigated in water, acidic buffer (pH-1.2) and in phosphate buffer (pH-6.8). In some of the solid dispersions, IBU lost its crystalline structure and converted into amorphous powder. Scanning electron micrographs and DSC thermograms revealed the absence of IBU crystalline particles in few of the solid dispersion matrixes. Solid dispersion comprising amorphous IBU showed remarkable enhancement in its solubility. The IBU-magnesium oxide solid dispersion showed the highest solubility enhancement, followed by IBU-hydroxypropyl-β-cyclodextrin, IBUpolyethylene glycol-6000, IBU-urea and IBU-β-cyclodextrin. The magnesium oxide, hydroxypropyl-β- cyclodextrin and β-cyclodextrin enhanced solubility even at acidic pH. Effervescence assisted fusion technique showed better solubility results than the other two techniques. On the basis of present observations, it can be suggested that the type of carrier matrix, the method of preparation and the pH of the dispersion plays an important role in the solubility of IBU.