title: Obtaining Lissamine Green 1% Solution for Clinical Use.
abstract: OBJECTIVE
  With new compounding pharmacy laws, the only economically feasible approach to using lissamine is through dye-impregnated strips. This research aims to determine the concentration of lissamine that can be obtained using a single commercially available lissamine strip. With the optimal vital staining requiring 1% concentration of lissamine, we sought to obtain this concentration using supplies in an ordinary ophthalmology clinic.
  
  
  METHODS
  A standard curve was generated using compounded lissamine green 1% solution. Serial dilutions were made with 3 different diluents and measured using a spectrophotometer at a wavelength of 633 μm. Combinations of the number of strips, amount of solvent, and absorption time were performed to obtain a 1% solution. Cost analyses were performed to select the most economical method.
  
  
  RESULTS
  Single lissamine strips wetted with any of the diluents produced 0.17% ± 0.05% (95% confidence interval) lissamine solution, a 5-fold weaker concentration than the optimal for vital staining. Combinations of 4 strips in 200 μL (4 drops) for 1 minute and 2 strips in 200 μL for 5 minutes were found to reach concentrations of 1%. Cost analysis showed that the 2 strip/4 drops/5 minutes method costs $0.67 and the 4 strips/4 drops/1 minute method $1.27.
  
  
  CONCLUSIONS
  Use of a single lissamine strip leads to suboptimal concentrations for vital staining. With only the addition of disposable microcentrifuge tubes to the clinical setting, ophthalmologists can make 1% solutions of lissamine. This solution is both more economical and in compliance with both state and national compounding laws.
authors: Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, MO.
authors: Michael
authors: M
authors: Stock
authors: David
authors: D
authors: Salvay
authors: Bradley
authors: B
authors: Shoss
authors: Kisha
authors: K
authors: Piggott
authors: Susan M
authors: SM
authors: Culican
mesh_terms: D004396:Coloring Agents / Q000032:analysis*; D003941:Diagnostic Techniques, Ophthalmological; D004339:Drug Compounding; D006801:Humans; D008086:Lissamine Green Dyes / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000737:chemistry; D011934:Reagent Strips / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D008086:Lissamine Green Dyes; D004364:Pharmaceutical Preparations; D011934:Reagent Strips