Preparation, Characterization and Evaluation of Olmesartan Medoxomil-β Cyclodextrin Complexes

Olmesartan medoxomil is a poor water soluble drug. There are numerous approaches available and reported in literature to enhance the solubility of poor water soluble drugs among which cyclodextrin complexation is predominant. β-cyclodextrin was used since this possess a special ability to complex with drugs enabling them to increase solubility, reduce bitterness, enhance stability and decrease tissue irritation upon dosing. Olmesartan medoxomil-β cyclodextrin complexes were prepared and characterized by FT-IR and SEM, studies. The results showed the formation of true inclusion complexes at molar ratio 1:5. In contrast crystalline drug was detectable in all other products. The dissolution of Olmesartan medoxomil from all the prepared complexes has been carried out to determine the most appropriate ratio that can be used for further development like tablet formulation for oral delivery. The complexes prepared by physical mixture method in 1:5 ratio showed superior dissolution profile when compared to complexes prepared in other ratios. From this research work it can be concluded that β CD has potential to increase the solubility of Olmesartan medoxomil and true complexes are formed in 1:5 ratio and because of the higher dissolution profile it can be used for further formulations. INTRODUCTION Orally administered drugs completely absorb only when they show fair solubility in gastric medium and such drugs shows good bioavailability. Recently more than 40% NCEs (new chemical entities) developed in Pharmaceutical Industry are practically insoluble in water. These poorly water soluble drugs are allied with slow drug absorption leading to inadequate and variable bioavailability and gastrointestinal mucosal toxicity. Therefore, the improvement of drug solubility thereby its oral bio-availability remains one of most challenging aspects of drug development process especially for oral drug delivery system. There are numerous approaches available and reported in literature to enhance the solubility of poorly water soluble drug. The techniques are chosen on the basis of certain aspects such as properties of drug under consideration, nature of excipients to be selected and nature of intended dosage form. Among all the solubility enhancement techniques inclusssion complex formation technique has been employed more precisely to improve the aqueous solubility, dissolution rate, and bioavailability of poorly water soluble drugs. Inclusion complexes are formed by the insertion of the nonpolar molecule or the nonpolar region of one molecule (known as guest) into the cavity of another molecule or group of molecules (known as host). The most commonly used host molecules are cyclodextrins. Olmesartan is one of …