Purpose: Gliclazide has been found to form inclusion complexes with β-cyclodextrin (β-CD) in

In the present study, an attempt was made to prepare immediate-release enteric-coated pellets of aceclofenac, a poorly soluble nonsteroidal anti-inflammatory drug that has a gastrointestinal intolerance as its serious side effect. Formulation of enteric-coated pellets with improved solubility of aceclofenac could address both of these problems. To achieve these goals, pellets were prepared by extrusion-spheronization method using pelletizing agents that can contribute to the faster disintegration and thereby improve the solubility of the drug. Different disintegrants like beta-cyclodextrin, kollidon CL, Ac-Di-Sol, and sodium starch glycolate were tried in order to further improve disintegration time. The pellets were characterized for drug content, particle size distribution, flow properties, infrared spectroscopy, surface morphology, disintegration rate, and dissolution profile. The formulations, which showed best disintegration and dissolution profiles, were coated with Eudragit L100-55, an enteric-coated polymer which does not dissolve at gastric pH but dissolves at intestinal pH, releasing the drug immediately in the dissolution medium. The optimized enteric-coated formulation containing 20% kappa-carrageenan, lactose, and sodium starch glycolate as a disintegrant did inhibit the release of the drug for 2 h in 0.1 N HCl, whereas 87% of the drug was released within 45 min. The improvement was substantial when it was compared with solubility of pure drug under the same conditions. Thus, dissolution profiles suggested that combination of kappa-carrageenan and sodium starch glycolate resulted into fast-disintegrating, immediate-release pellets, overcoming the bioavailability problem of the poorly soluble drug, aceclofenac, and enteric coating of these pellets avoids the exposure of aceclofenac to ulcer-prone areas of the gastrointestinal tract.

Fexofenadine is a selective histamine H1 receptor antagonist, used for relief of the symptoms of allergy. However its aqueous solubility is very poor. Solid inclusion complexes of fexofenadine and β-cyclodextrin were prepared at the molar ratios of 1:1 and 1:2 by kneading, and coprecipitation methods to improve its solubility. Characterization of the complexes was performed using infrared spectroscopy, X-ray diffractometry, and in vitro dissolution studies. Fexofenadine was found to exhibit interaction with β-cyclodextrin both in solid and liquid state. Phase solubility studies indicated that fexofenadine forms a stable complex with β-cyclodextrin. Both IR spectroscopy and X-ray diffractometry studies indicated interaction of fexofenadine with β-cyclodextrin. Kneading method at 1:1 and co-precipitation method at 1:1 and 1:2 molar ratios showed significant interaction. In vitro dissolution studies confirmed the same results.

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