title: Effect of freezing, long-term storage and microwave thawing on the stability of a mixture of diclofenac and sodium bicarbonate in glucose 5% polyolefin bags.
abstract: OBJECTIVE
  Preparation in advance of intravenous solution could be efficient to improve quality assurance, security, time management and cost saving of drug delivery. The aim of this study was to investigate the stability of a mixture of diclofenac 75 mg/100 ml and sodium bicarbonate 42 mg/100 ml in 5% glucose polyolefin bags after freezing, long-term storage, and microwave thawing.
  
  
  METHODS
  The stability of five polyolefin bags containing approximately 75 mg/100ml of diclofenac and 42 mg/100ml of sodium bicarbonate in 5% glucose prepared under aseptic conditions was studied after freezing for 2 months at -20 degrees C, thawing in a microwave oven with a validated cycle, and stored at 5 + or - 3 degrees C. Diclofenac concentrations were measured by high-pressure liquid chromatography using a reversed-phase column, a mobile phase consisting of 40% of acetonitrile (v/v) in KH(2)PO(4) buffer 0.02 M, pH 8.40 + or - 0.05, and UV detection at 276.0 nm. Visual inspection, microscope observation, spectrophotometric measurements and pH measurement were also performed.
  
  
  RESULTS
  No colour change or precipitation occurred in the preparations. No microaggregate was observed with optical microscopy or revealed by a change of absorbance. Based on a shelf-life of 90% residual potency, diclofenac was stable for at least 30 days after freezing and microwave thawing, period where 95% lower confidence limit of the concentration-time profile remained superior to 90% of the initial concentration. During this period, the pH values of drug solutions have not been altered.
  
  
  CONCLUSIONS
  Within these limits, diclofenac in 5% glucose infusion may be prepared and frozen in advance by a centralized intravenous admixture service, then thawed before use in clinical units.
authors.affiliation: Medical Laboratory, cliniques universitaires UCL Mont-Godinne, 1, avenue Therasse, 5530 Yvoir, Belgium.
authors.forename: J-H
authors.initials: JH
authors.lastname: François
authors.forename: J-D
authors.initials: JD
authors.lastname: Hecq
authors.forename: D
authors.initials: D
authors.lastname: Vanbeckbergen
authors.forename: J
authors.initials: J
authors.lastname: Jamart
authors.forename: L
authors.initials: L
authors.lastname: Galanti
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry*; D004008:Diclofenac / Q000737:chemistry*; D004339:Drug Compounding; D004349:Drug Packaging; D004355:Drug Stability; D004356:Drug Storage; D005615:Freezing; D005947:Glucose / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008872:Microwaves; D019999:Pharmaceutical Solutions; D011090:Polyenes; D017693:Sodium Bicarbonate / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D019999:Pharmaceutical Solutions; D011090:Polyenes; D004008:Diclofenac; C035051:PL 732; D017693:Sodium Bicarbonate; D005947:Glucose