title: Accelerated stability studies for moisture-induced aggregation of tetanus toxoid.
abstract: OBJECTIVE
  The study was carried out to evaluate the effect of exposing solid tetanus toxoid to moisture in two different ways on the structure and function of the toxoid.
  
  
  METHODS
  Tetanus toxoid was exposed to moisture by (i) the addition of an optimized amount of buffer and (ii) incubation under an environment provided by a saturated solution of K(2)CrO(4.) The changes in the conformational, structural and antigenic properties of tetanus toxoid were measured and compared.
  
  
  RESULTS
  Results show that even at a similar level of moisture-induced aggregation, the amounts of water absorbed by the two preparations of tetanus toxoid are different. Differences in antigenicity and changes in structure of the toxoid at primary, secondary and tertiary structure levels were seen.
  
  
  CONCLUSIONS
  Although both conditions are used to mimic accelerated stability conditions in the laboratory, the final products are different in the two cases. Thus, conditions for 'accelerated stability studies' for therapeutic proteins need to be selected with care so that they resemble the fate of the actual product.
authors.affiliation: Department of Biotechnology, National Institute of Pharmaceutical Education & Research, Sector 67, SAS Nagar, Punjab 160062, India.
authors.forename: Nishant Kumar
authors.initials: NK
authors.lastname: Jain
authors.forename: Ipsita
authors.initials: I
authors.lastname: Roy
mesh_terms: D004355:Drug Stability; D006813:Humidity / Q000592:standards; D013745:Tetanus Toxoid / Q000737:chemistry* / Q000592:standards; D013997:Time Factors
chemical_list: D013745:Tetanus Toxoid