title: The effect of calcium hydroxide on the steroid component of Ledermix and Odontopaste.
abstract: OBJECTIVE
  To investigate the chemical interaction of calcium hydroxide with the corticosteroid triamcinolone acetonide in Ledermix Paste and in Odontopaste, a new steroid/antibiotic paste.
  
  
  METHODS
  Validated methods were developed to analyse the interaction of calcium hydroxide in two forms, Pulpdent Paste and calcium hydroxide powder, with triamcinolone acetonide within Odontopaste and Ledermix Paste. High-performance liquid chromatography (HPLC) was used to analyse the mixed samples of the pastes and calcium hydroxide. The concentration of triamcinolone acetonide within the pastes was determined over 0, 2, 6, 24 and 72-h time-points. All tests with the HPLC involved the testing of the standard with triplicate injections alongside the samples. All samples were tested in duplicate with each injected twice; therefore, four tests were performed for each investigation. Linearity, precision and specificity of the testing procedures and apparatus were validated. Descriptive statistics are provided.
  
  
  RESULTS
  In both pastes, there was a marked rapid destruction of the triamcinolone acetonide steroid upon mixing with calcium hydroxide. Odontopaste suffered a lower rate of destruction of the triamcinolone acetonide component than Ledermix Paste, but both pastes showed very similar degrees of steroid destruction after 72 h. When using calcium hydroxide powder with Ledermix Paste, the triamcinolone was destroyed entirely and immediately.
  
  
  CONCLUSIONS
  The addition of calcium hydroxide to Odontopaste or Ledermix Paste results in the rapid destruction of the steroid.
authors: Australian Dental Manufacturing, Brisbane, Qld., Australia.
authors: M
authors: M
authors: Athanassiadis
authors: N
authors: N
authors: Jacobsen
authors: P
authors: P
authors: Parashos
mesh_terms: D000468:Alkalies / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000032:analysis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002981:Clindamycin / Q000032:analysis / Q000737:chemistry*; D003707:Demeclocycline / Q000032:analysis / Q000737:chemistry*; D004338:Drug Combinations; D004347:Drug Interactions; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D011208:Powders; D012388:Root Canal Irrigants / Q000032:analysis / Q000737:chemistry*; D013997:Time Factors; D014222:Triamcinolone Acetonide / Q000032:analysis / Q000737:chemistry*
chemical_list: D000468:Alkalies; D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D011208:Powders; D012388:Root Canal Irrigants; C029777:Pulpdent; D002981:Clindamycin; D003707:Demeclocycline; C001527:Ledermix; D014222:Triamcinolone Acetonide; D002126:Calcium Hydroxide