title: Stability of clonidine suspension in oral plastic syringes.
abstract: OBJECTIVE
  The stability of clonidine suspensions stored at room temperature and under refrigeration for three months was evaluated.
  
  
  METHODS
  Oral suspensions of clonidine 0.01 mg/mL were prepared in Ora-Blend and stored in clear plastic syringes at 25 °C and 4 °C. Samples were collected from each syringe at the time of preparation, at weekly intervals for up to 28 days, and on days 42, 56, 77, and 91. Changes in color, taste, and pH, as well as visual evidence of precipitation, were used to determine physical compatibility. Immediately after the physical observations were made, 1.5-mL samples from each syringe were transferred to polypropylene freezer vials and stored at -85 °C until high-performance liquid chromatographic (HPLC) analysis. The samples were analyzed by a validated stability-indicating HPLC-ultraviolet-light detection method. Stability was defined as the retention of at least 90% of the initial clonidine concentration. The precision of the assay was evaluated by intraday and interday validation methods.
  
  
  RESULTS
  Clonidine suspensions stored at 25 °C and 4 °C maintained 99.2% and 99.0% of the initial concentration for 91 days, respectively. No interfering peaks were generated by forced degradation of clonidine with heat, hydrochloric acid, sodium hydroxide, or hydrogen peroxide There were no notable changes in pH, and all samples remained physically unchanged during the study period.
  
  
  CONCLUSIONS
  An extemporaneously prepared suspension of clonidine 0.01 mg/mL in Ora-Blend was stable for at least 91 days when stored in clear plastic syringes at either 25 °C or 4 °C.
authors.affiliation: Carmen Ma, B.Sc.Pharm., is Pharmacist, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada. Diane Decarie, B.Sc., is Research Consultant, Department of Pharmacy, Children's and Women's Health Centre of British Columbia, Vancouver, British Columbia, Canada. Mary H. H. Ensom, Pharm.D, FASHP, FCCP, FCSHP, FCAHS, is Professor of Pharmaceutical Sciences, University of British Columbia, Vancouver, and Clinical Pharmacy Specialist, Children's and Women's Health Centre of British Columbia.
authors.forename: Carmen
authors.initials: C
authors.lastname: Ma
authors.forename: Diane
authors.initials: D
authors.lastname: Decarie
authors.forename: Mary H H
authors.initials: MH
authors.lastname: Ensom
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists / Q000008:administration & dosage / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D003000:Clonidine / Q000008:administration & dosage / Q000737:chemistry*; D004355:Drug Stability; D004356:Drug Storage; D006863:Hydrogen-Ion Concentration; D011126:Polypropylenes / Q000737:chemistry*; D012034:Refrigeration; D013535:Suspensions; D013594:Syringes; D013696:Temperature; D013997:Time Factors
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D011126:Polypropylenes; D013535:Suspensions; D003000:Clonidine