title: Examination of purification methods and development of intravitreal injection of triamcinolone acetonide.
abstract: OBJECTIVE
  Intravitreal injection of triamcinolone acetonide (TA) is used in ophthalmic treatment, but the reliability of commercially available TA preparations has still not been established. We evaluated two previously reported purification methods, and developed a more reliable TA injection which can be prepared in a hospital pharmacy.
  
  
  METHODS
  We tested the two methods previously reported for purifying commercial TA preparations, the sedimentation and the filtration and backflushing methods. We developed a new TA injection made of pure TA suspended in 0.5% sodium hyaluronate. We measured the TA content in each preparation by high-performance liquid chromatography to evaluate the three methods.
  
  
  RESULTS
  In the sedimentation purification method, the TA content of a nominal 4-mg preparation varied from 1.43 to 7.37 mg, and the average recovery rate was 91.6%. In the filtration and backflushing method, TA content was 0.10-10.33 mg and recovery was 59.5%. In the TA injection we developed, the mean TA content was 102.5% (SD, 0.24; CV, 2.9%). The stability of this preparation was 99% after sterilization, and 97% after 3 months of storage.
  
  
  CONCLUSIONS
  The results of our investigation showed that the purification methods used for commercial preparations are simple and easy but not precise enough for an intravitreal injection. In contrast, the TA injection prepared by our method is reliable, stable, and safe enough for clinical use.
authors.affiliation: Department of Pharmacy, Osaka University Hospital, Osaka, Japan. oishi@hp-drug.med.osaka-u.ac.jp
authors.forename: Masako
authors.initials: M
authors.lastname: Oishi
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Maeda
authors.forename: Ayumi
authors.initials: A
authors.lastname: Nakamura
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kurokawa
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ohguro
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tano
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005938:Glucocorticoids / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D007267:Injections; D009883:Ophthalmic Solutions / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D014222:Triamcinolone Acetonide / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D014822:Vitreous Body
chemical_list: D005938:Glucocorticoids; D009883:Ophthalmic Solutions; D014222:Triamcinolone Acetonide