Abstract—The rapid expansion of supercritical solution (RESS) process was successfully applied in this study for the recrystallization and micronization of an active pharmaceutical ingredient (API) of 4-dimethylaminoantipyrine. The untreated 4-dimethylaminoantipyrine had a large mean particle size with very wide particle size distribution ranging from 22 to 2468 μm. After the RESS treatment, the mean particle size of this API was significantly reduced to the desirable range of 1 to 5 μm. Furthermore, more uniform and much narrower particle size distribution was obtained after the RESS process. It was observed that the variation of the pre-expansion and post-expansion temperatures has significant effect on the mean particle size, particle size distribution and crystal habit. The DSC and XRD analyses results showed that there was polymorph transformation during the RESS process. The dissolution rate measurements had been conducted for the original and RESS treated APIs. The results demonstrated that higher dissolution efficiency was obtained as a consequence of significant particle size reduction.
Index Terms—Micronization, ress, 4-dimethylaminoantipyrine, polymorph.
Chai-Siah Lee and Yan-Ping Chen are with the Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (email: ypchen@ntu.edu.tw).
Muoi Tang and Sheau-Ling Ho are with the Department of Chemical and Materials Engineering, Chinese Culture University, Taipei, Taiwan.
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Cite: Chai-Siah Lee, Muoi Tang, Sheau-Ling Ho, and Yan-Ping Chen, "Recrystallization and Micronization of 4-Dimethylaminoantipyrine Using the Rapid Expansion of Supercritical Solution (RESS) Process," International Journal of Chemical Engineering and Applications vol. 6, no. 6, pp. 427-431, 2015.
