title: Variability in tablet fragment weights when splitting unscored cyclobenzaprine 10 mg tablets.
abstract: OBJECTIVE
  To determine the weight variation and calculated dosing variability of tablet fragments upon splitting unscored cyclobenzaprine hydrochloride 10 mg tablets using two common tablet splitting devices.
  
  
  METHODS
  Comparative pharmaceutics study.
  
  
  METHODS
  Pharmacy school laboratory.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Unscored cyclobenzaprine hydrochloride 10 mg tablets from one generic manufacturer were split with a tablet splitter or a kitchen knife by a licensed pharmacist and two doctor of pharmacy students (n = 15 tablets for each method per participant).
  
  
  METHODS
  Fragment weights (FWs) were compared with the theoretical weights (TWs), which were calculated as one half of the mean weight of the tablets used in each part of the experiment; means, relative standard deviations (RSDs), and percentages of TW were also calculated.
  
  
  RESULTS
  The mean weight before splitting the 45 tablets with the tablet splitter was 136.6 +/- 2.1 mg (TW = 68.3 mg). The mean FW after splitting was 67.9 +/- 7.9 mg. The RSD of 11.6% corresponded to a range of 69.4% to 130.2% of the TW and an estimated drug content of the split fragments between 3.47 mg and 6.51 mg. The mean weight before splitting the 45 tablets cut with a kitchen knife was 136.6 +/- 2.0 mg (TW = 68.3 mg). The mean FW was 68.0 +/- 15.7 mg with a RSD of 23.2%, corresponding to a range of 49.9% to 149.5% of the TW and an estimated drug content of the split fragments between 2.49 mg and 7.48
  
  
  CONCLUSIONS
  Tablet fragments obtained after splitting this generic cyclobenzaprine 10 mg product varied considerably in weight and estimated drug content. Accordingly, splitting cyclobenzaprine 10 mg tablets to achieve 5 mg doses could result in unpredictable dosing and therapeutic response.
authors.affiliation: Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA. tjcook@rci.rutgers.edu
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Cook
authors.forename: Shanya
authors.initials: S
authors.lastname: Edwards
authors.forename: Charlene
authors.initials: C
authors.lastname: Gyemah
authors.forename: Manoj
authors.initials: M
authors.lastname: Shah
authors.forename: Indu
authors.initials: I
authors.lastname: Shah
authors.forename: Tiziana
authors.initials: T
authors.lastname: Fox
mesh_terms: D000639:Amitriptyline / Q000031:analogs & derivatives*; D004339:Drug Compounding / Q000379:methods*; D013607:Tablets; D014149:Tranquilizing Agents
chemical_list: D013607:Tablets; D014149:Tranquilizing Agents; D000639:Amitriptyline; C004704:cyclobenzaprine