Oral route of drug administration have wide acceptance up to 50-60% of total dosage forms. Bioavailability and solubility are important in oral dosage forms. Olmesartan medoxomil is an angiotensin II receptor antagonists which lowers high blood pressure. It has low bioavailability and aqueous solubility. The purpose of present investigation was to improve the solubility of Olmesartan medoxomil by solid dispersion and formulation of mouth dissolving tablets to provide quick therapeutic action in the hypertension. Solid dispersions prepared by solvent evaporation method showed solubility enhancement in order of Polyethylene Glycol 4000 ˃ Polyvinylpyrolidone K30 ˃ Poloxamer 188. Solid dispersion of Omesartan Medoxomil with Polyethylene Glycol 4000 in the weight ratio of 1:1 was optimized for preparation of tablets as improved solubility and dissolution rate of Olmesartan Medoxomil compared to pure drug. This binary system was characterized by FT-IR spectroscopy, differential scanning calorimetry and X-Ray diffraction. Optimized solid dispersion showed the presence of amorphous form of drug confirmed by the characterization study. Mouth dissolving tablet of Olmesartan medoxomil based on solid dispersion was prepared by direct compression using different combination of Kyron T-314 and Crospovidone. An optimized formulation F14 had above 90 % cumulative drug release within 3 min, wetting time 20.02 ± 0.03 sec and in-vitro disintegration time 16.61 ± 0.87 sec. Release kinetic model study indicated that all formulations followed Zero order kinetics. Further it was observed that all batches followed constant rate release as per Weibull and Hixson-Crowell model. Stability studies indicated that there were no significant changes in tablet parameters and was stable and reproducible at plant scale.
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