Micronization of p-aminosalicylic acid particles using high-gravity technique

An antisolvent precipitation process was adopted in this study to prepare micrometer-sized p-aminosalicylic acid (PAS) particles using the high-gravity technique. The effects of operating variables on the particle size were investigated. With an increase in the dispersant concentration and disk diameter or a decrease in the drug (PAS) concentration, the particle size of PAS was reduced. In addition, a circular-tube distributor was more effective than a straight-tube distributor for micronization. On the other hand, the effect of the liquid flow rate in the range between 0.25 and 1 L/min was less significant. The high-pressure homogenization following the high-gravity precipitation would effectively reduce the agglomeration of the particles in the suspension to produce drug particles with a mean size of 1 μm. The enhancement of the dissolution rate was significant for the micronized drug particles. The results indicate that the high-gravity process is a promising approach for micronizing drug particles.