Content Uniformity, Adhesion and Stability of Propylthiouracil Powder Prepared by Pulverizing Tablets

Propylthiouracil (PTU), an antithyroid drug, has been widely used to treat hyperthyroidism. Since any dosage form other than tablet form is not commercially available for PTU, it is necessary to prepare the powder by pulverizing the tablet when dose adjustment is required. To clarify the efficacy of pulverizing the PTU tablet, we investigated the content uniformity, adhesiveness and long-term stability of PTU in three kinds of powders prepared with different excipients; EFC lactose, powdered lactose and potato starch.The content uniformity of PTU was excellent in all powders. In addition, there was no adhesion of PTU to two kinds of wrapping papers. On the other hand, dividing and packaging tests performed by automatic machine showed a slight effect of the excipients on PTU adhesion to the machine, specifically the lost amount of PTU after dividing and packaging was approximately 6-10% of the initial amount in all powders.PTU in these powders was almost completely stable by 90 days under the following storage conditions: R. H. 92% at 30°C, exposure to light at room temperature, and protection from light at 5°C. In addition, there was no apparent difference in the remaining percentage of PTU among these powders under each of the storage conditions. However, PTU remaining under R. H. 92% at 30°C tended to be lower than those under other storage conditions.The present findings suggest that these PTU preparations made by pulverizing tablets are applicable to practical long-term therapy use.