Influence of crug solubility, binders and pellet size in formulating sustained release pellets

The aim of the present study was to investigate the effects of drug solubility, inert pellet size \nand binders used in drug loading on release behavior from Eudragit NE-30 coated pellets. Aqueous solutions \nof highly water soluble drugs, diltiazem hydrochloride and chlorpheniramine maleate while hydroalcoholic \nsolutions of poorly soluble drugs, diclofenac sodium and theophylline were applied onto inert \npellets to produce drug pellets, which were subsequently coated with aqueous polymer dispersion using \nbottom spray fluidized-bed coater. Coated pellets were cured at 37 ºC for 24 h prior to dissolution studies. \nDrug release from coated pellets using different drugs showed different release profiles. The larger size \npellets displayed significantly slower release rate compared to smaller size pellets. A faster drug release \nwas achieved with PVP for drug loading in contrast to slower release profile with HPMC. Drug pellets can \nbe differentiated using scanning electron microscope compared to pellets coated with Eudragit NE-30