title: Stability of a mixture of technetium Tc 99m sulfur colloid and lidocaine hydrochloride.
abstract: OBJECTIVE
  The stability of a mixture of technetium Tc 99m sulfur colloid and lidocaine hydrochloride for up to eight hours was studied.
  
  
  METHODS
  Three vials of technetium Tc 99m sulfur colloid were compounded according to the manufacturer's instructions. From each of the three vials, five samples were withdrawn into syringes with needles: 0.4, 0.45, 0.5, 0.63, and 1 mCi for testing after storage for zero, one, two, four, and eight hours, respectively. Each syringe contained the customary patient dose of 0.4 mCi at the time of testing. Fresh 0.9% sodium chloride injection was used to bring the volume of each syringe to 0.2 mL, and 0.2 mL of lidocaine hydrochloride 1% was added to bring the final volume to 0.4 mL. Measurements of pH, radiochemical purity, and particle size were conducted after the indicated storage times for each group of samples.
  
  
  RESULTS
  The pH of samples showed no substantial change over the eight-hour storage period, with individual values in the range of 4.5-5.5. Radiochemical purity did not change substantially, with values ranging from 98.9% to 99.9%. There was no meaningful change in the amount of radioactivity retained by filtration and no increase in particle size.
  
  
  CONCLUSIONS
  Adding lidocaine hydrochloride 1% to syringes containing technetium Tc 99m sulfur colloid and storing the syringes for up to eight hours had no effect on the pH or radiochemical purity of the mixture or on the radioactivity retained by a filter.
authors.affiliation: College of Pharmacy, The Ohio State University, Columbus 43210, USA.
authors.forename: Jillian V
authors.initials: JV
authors.lastname: Dura
authors.forename: George H
authors.initials: GH
authors.lastname: Hinkle
mesh_terms: D001391:Azo Compounds; D002855:Chromatography, Thin Layer; D004339:Drug Compounding; D004355:Drug Stability; D004356:Drug Storage / Q000379:methods / Q000592:standards; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000737:chemistry*; D011851:Radioactivity; D011854:Radiochemistry; D019275:Radiopharmaceuticals; D013594:Syringes; D013671:Technetium Tc 99m Sulfur Colloid / Q000737:chemistry*; D013997:Time Factors
chemical_list: D001391:Azo Compounds; D019275:Radiopharmaceuticals; C013617:nitrazine yellow; D013671:Technetium Tc 99m Sulfur Colloid; D008012:Lidocaine