Comparison of Polymers In Enhancing the Dissolution Rate of Olmesartan Medoxomil By Solid Dispersion Technique Using Solvent Evaporation Method

The present study involved preparation of solid dispersions of Olmesartan medoxomil to improve the aqueous solubility and dissolution rate in order to enhance bioavailability. Olmesartan is a BCS Class II anti-hypertensive drug, having low aqueous solubility and low bioavailability of 26%.  In the present study, solid dispersions of Olmesartan with different carriers like Poloxamer 407, PEG 4000  and crospovidone in different ratios (1 : 1, 1 : 2, 1 : 3, 1 : 4) were prepared by solvent evaporation method.  The formulations were further characterized for percentage yield, drug content, in vitro release study,  and stability study. In vitro release studies revealed that the solid dispersions prepared by solvent evaporation method crospovidone (1 : 4) was considered as the best formulation because of its faster drug release among all formulations.  Infrared spectroscopy (IR) studies revealed that no interactions exist between drug and polymer. Powder X-ray diffraction studies showed a significant decrease in crystalline nature of drug in solid dispersions. In conclusion, solid dispersions of Olmesartan in crospovidone (1:4) have shown to be a promising approach to enhance the bioavailability of Olmesartan.