Abstract
Acetaminophen and ascorbic acid, which are slightly and highly soluble in water, respectively, were granulated with a low viscosity grade of hydroxypropylcellulose (HPC-L) aqueous solution by high-speed mixing, fluidized bed granulation, and spray drying. The granules obtained were compacted into tablets and their strengths were evaluated.The binding strength of acetaminophen granules increased with increase in the amount of water used, irrespective of the granulation method. On the other hand, the binding strength of ascorbic acid granules depended greatly on the granulation method and decreased when an excessive amount of water was used. The ascorbic acid granules obtained by fluidized bed and spray drying granulation with the minimum amount of water exhibited high compressibitlity. In these granules, the surface of crystals was found to be entirely coated with the binder. It is considered that the high solubility of the drug in the binder solution enabled such coating to occur, though excessive dissolution of the drug led to a decrease in compressibility.
