title: Preparation of stable micron-sized crystalline irbesartan particles for the enhancement of dissolution rate.
abstract: OBJECTIVE
  In this study, micron-sized crystalline drug particles of irbesartan (IBS) were prepared to improve its stability and dissolution rate.
  
  
  METHODS
  The approach to crystalline particles was based on the liquid precipitation process by which the amorphous particles were prepared. Pharmaceutical acceptable additives were used as the crystallization agent to convert the amorphous drug into crystalline particles. High pressure homogenization (HPH) process has been employed to reduce the size of the crystalline particles, and the micron-sized particles were obtained by the freeze-drying process.
  
  
  RESULTS
  Different additives show different influences on the polymorphic form of IBS. Polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC) were effective in stabilizing amorphous particles instead of converting amorphous drug into crystalline particles, while poloxamer407 (F127) and tween80 (T80) could convert the amorphous drug into crystalline particles. T80 was also effective in controlling the particle size than that of F127. After HPH, crystalline particles with an average of 0.8 μm were obtained. The freeze-dried micron-sized crystalline particles exhibited significantly enhanced in vitro dissolution rate when compared to the raw drug. SEM, FT-IR, XRD, DSC and dissolution rate studies indicated that the micron-sized particles were stable during 6 months storage.
  
  
  CONCLUSIONS
  The preparation of micron-sized crystalline drug particles is an effective way to improve the stability and dissolution rate of irbesartan.
authors.affiliation: Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing, PR China.
authors.forename: Zhi-Liang
authors.initials: ZL
authors.lastname: Zhang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Le
authors.forename: Jie-Xin
authors.initials: JX
authors.lastname: Wang
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Chen
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000737:chemistry*; D001682:Biological Availability; D001713:Biphenyl Compounds / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003460:Crystallization; D005612:Freeze Drying; D000077405:Irbesartan; D010316:Particle Size; D012995:Solubility; D013777:Tetrazoles / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D001713:Biphenyl Compounds; D013777:Tetrazoles; D000077405:Irbesartan