title: Potential for airborne contamination in turbulent- and unidirectional-airflow compounding aseptic isolators.
abstract: OBJECTIVE
  The ability of turbulent- and unidirectional-airflow compounding aseptic isolators (CAIs) to control airborne contamination during aseptic compounding of compounded sterile preparations (CSPs) was studied.
  
  
  METHODS
  A three-phase challenge of the comparative airborne-contamination management capabilities of five CAIs was conducted using augmented, industry-standard visual tracer and discrete particle counting methods. In phase 1, a visual smoke tracer was used to conduct a standardized, comparative challenge. In phase 2, CAI operational contamination-control capabilities were measured in accordance with the International Organization for Standardization (ISO) class 5 air cleanliness conditions using a standardized CSP process qualification procedure. Alcohol drying times were also compared. In phase 3, the gross contamination clearance interval required to achieve the ISO class 5 condition after a gross contamination event was measured for each CAI.
  
  
  RESULTS
  All four unidirectional-airflow CAIs met ISO class 5 cleanliness requirements throughout all testing phases and areas of the work zone and demonstrated alcohol drying times of 16 seconds or less. The turbulent-airflow CAI tested failed to achieve the ISO class 5 operating condition at any time during the testing and required alcohol drying times of six minutes. The unidirectional-airflow CAIs tested met the laminar-airflow workstation-equivalency requirements of chapter 797 of the United States Pharmacopeia, pharmaceutical aseptic processing standards, the industry-standard definition of a closed isolator, and the rigorous demands of pharmacy and nursing sterile compounding.
  
  
  CONCLUSIONS
  The performance of four unidirectional-flow CAIs supports their use in pharmacy and nursing CSP operations, whereas the performance of one turbulent-flow CAI does not.
authors.affiliation: Lab Safety Corporation, Cumberland, WI, USA. valiteq@aol.com
authors.forename: Gregory F
authors.initials: GF
authors.lastname: Peters
authors.forename: Marghi R
authors.initials: MR
authors.lastname: McKeon
authors.forename: William T
authors.initials: WT
authors.lastname: Weiss
mesh_terms: D016902:Air Pollution, Indoor; D001207:Asepsis / Q000295:instrumentation / Q000379:methods*; D004339:Drug Compounding / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D004340:Drug Contamination / Q000517:prevention & control*; D004780:Environment, Controlled; D004364:Pharmaceutical Preparations / Q000592:standards*; D010602:Pharmacopoeias as Topic / Q000592:standards; D011786:Quality Control; D014481:United States
chemical_list: D004364:Pharmaceutical Preparations