title: Micronization of phenylbutazone by rapid expansion of supercritical CO2 solution.
abstract: Rapid expansion of supercritical solutions (RESS) technique was applied for the preparation of phenylbutazone fine particles. The operating temperature and pressure affected the yield of the drug fine particles, which was evaluated by dissolving the sprayed product of drug into ethanol. Effect of pre- and post-expansion conditions on the particle size distribution of phenylbutazone was investigated and the smallest sample (mean particle size: 1.59 microm) was obtained when the RESS method was operated at a pressure of 26 MPa combined with a temperature of 32 degrees C. Physicochemical properties of the fine particles were investigated by powder X-ray diffraction and differential scanning calorimetry. It was found that the phenylbutazone fine particles obtained were meta-stable beta form under the experimental conditions tested, suggesting polymorphic transformation during the RESS process.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. moribe@p.chiba-u.ac.jp
authors.forename: Kunikazu
authors.initials: K
authors.lastname: Moribe
authors.forename: Shun-ichiro
authors.initials: S
authors.lastname: Tsutsumi
authors.forename: Shoko
authors.initials: S
authors.lastname: Morishita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shinozaki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tozuka
authors.forename: Toshio
authors.initials: T
authors.lastname: Oguchi
authors.forename: Keiji
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D002152:Calorimetry, Differential Scanning; D002245:Carbon Dioxide / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D010316:Particle Size; D010653:Phenylbutazone / Q000737:chemistry*; D012996:Solutions; D014961:X-Ray Diffraction
chemical_list: D012996:Solutions; D002245:Carbon Dioxide; D000431:Ethanol; D010653:Phenylbutazone