title: Hydroxyisohexyl 3-cyclohexene carboxaldehyde (lyral) in patch test preparations under varied storage conditions.
abstract: BACKGROUND
  The common practice of preparing patch tests in advance has recently been called into question by researchers. It has been established that fragrance compounds are volatile and their testing efficacy may be affected by storage conditions and preparation. Allergens in fragrance mix I rapidly decrease in concentration after preapplication to test chambers.
  
  
  OBJECTIVE
  This study aimed to investigate the volatility of hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) in petrolatum when stored in test chambers and to explore the correlation between vapor pressure and allergen loss in petrolatum during preparation and storage.
  
  
  METHODS
  Standardized HICC in petrolatum was prepared and stored in IQ Chambers and Finn Chambers with covers at 5°C, 25°C, and 35°C, and concentration was analyzed at intervals for up to 9 days using gel permeation chromatography.
  
  
  RESULTS
  Changes in HICC concentrations were not statistically significant at 8 hours at 5°C, 25°C, and 35°C. After 9 days, HICC concentrations were found to fall approximately 30% when stored at 35°C, 10% at 25°C, and less than 5% at 5°C. There was no significant difference between IQ and Finn chambers.
  
  
  CONCLUSIONS
  Hydroxyisohexyl 3-cyclohexene carboxaldehyde concentrations are more stable in petrolatum than many other studied fragrance allergens, but HICC is still at risk for decreasing concentration when exposed to ambient air or heat for prolonged periods.
authors.affiliation: From the *College of Medicine, University of Arizona, Phoenix, AZ; †Department of Occupational and Environmental Dermatology, Skåne University Hospital, Lund University, Malmö, Sweden; and ‡School of Medicine, Loma Linda University, Loma Linda, CA.
authors.forename: Dathan
authors.initials: D
authors.lastname: Hamann
authors.forename: Carsten R
authors.initials: CR
authors.lastname: Hamann
authors.forename: Erik
authors.initials: E
authors.lastname: Zimerson
authors.forename: Magnus
authors.initials: M
authors.lastname: Bruze
mesh_terms: D000447:Aldehydes / Q000009:adverse effects / Q000737:chemistry* / Q000592:standards*; D000485:Allergens / Q000009:adverse effects / Q000737:chemistry*; D002850:Chromatography, Gel; D053138:Cyclohexenes / Q000009:adverse effects / Q000737:chemistry* / Q000592:standards*; D004355:Drug Stability; D004356:Drug Storage; D010328:Patch Tests; D010476:Perfume / Q000009:adverse effects / Q000737:chemistry*; D010577:Petrolatum; D014835:Volatilization
chemical_list: D000447:Aldehydes; D000485:Allergens; D053138:Cyclohexenes; D010476:Perfume; D010577:Petrolatum; C092244:hydroxyisohexyl 3-cyclohexene carboxaldehyde