title: [The photostability of hydrocortisone injection].
abstract: OBJECTIVE
  This experiment was designed to make known wether the photostability of drugs in daylight can be obtained from lamplight exposure.
  
  
  METHODS
  A self made cumulative illuminometer via pulse counting method was used for measuring cumulative illuminance of daylight to investige the photodegradation of Hydrocortisone injection in various lamp light and daylight; the equivalent influences of different light sources on the photostability of the injection were obtained, and the shelf-life in indoor daylight of the drug was predicted.
  
  
  RESULTS
  The photodegradation of Hydrocortisone injection obeys zero order kinetics: C = C0-kEt; the shelf-life in indoor daylight of the injection in nude ampoules was predicted as 36 days and is comparable to 35 days in a long-term storage test.
  
  
  CONCLUSIONS
  The photostability of drugs in daylight can be obtained from lamplight exposure experiment.
authors.affiliation: School of Pharmacy, WCUMS, Chengdu 610041, China.
authors.forename: T
authors.initials: T
authors.lastname: Lin
authors.forename: K
authors.initials: K
authors.lastname: Li
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.forename: C
authors.initials: C
authors.lastname: Qiu
authors.forename: X
authors.initials: X
authors.lastname: Zhan
mesh_terms: D004355:Drug Stability; D006854:Hydrocortisone; D007267:Injections; D008027:Light
chemical_list: D006854:Hydrocortisone