Properties of hydroxypropylmethylcellulose granules produced by water spraying

Granulation of powdered HPMCs stirred in a planetary mixer was induced by simple spraying with water. The influence of nozzle size, the amount of water added, and grade of HPMC on particle size, density, angle of repose, and compressibility was determined for the several granules produced. The properties of tablets made from them were also evaluated. It was found that the effect of process variables on the physical properties of neat HPMC granules is the same in the presence the drug, diclofenac sodium. Using a smaller sized nozzle results in a narrower granule size distribution. The amount of water needed to optimize granule size for tabletting is in the range of 90-120 ml per 200 g of powder mixture. The release of diclofenac sodium from such matrix tablets follows a non-Fickian mechanism; release is affected primarily by the grade of HPMC and the rate at which it hydrates.