Stability of theophylline in serum, plasma, and saliva stored at different temperatures.
Author(s): Jonkman JH, Franke JP, Schoenmaker R, de Zeeuw RA
Publication: Clin Chem, 1981, Vol. 27, Page 2071-2
PubMed ID: 7307261 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to determine the effects of storage on theophylline concentrations in spiked blood, serum and salive specimens.
Conclusion of Paper
Significant declines in theophylline concentrations were noted in all specimens stored at 25 degrees C for 7 days, in serum and saliva specimens stored at 6 degrees C for 7 days, and in serum and plasma stored at -20 degrees C for 6 months. However, the authors conclude that theophylline containing specimens can be stored for approximately 2 weeks at room temperature or refrigerated and for approximately 1.5 years at -20 degrees C without resulting in any clinically relevant changes to theophylline concentrations.
Studies
-
Study Purpose
The purpose of this study was to determine the effects of storage temperature and duration on theophylline concentrations in spiked plasma, serum and saliva specimens.
Summary of Findings:
Theophylline concentrations declined by 3% and 2.6% when spiked serum was stored for 1 week at 25 degrees C or 6 degrees C, respectively. Concentrations declined by 2.7% with storage at -20 degrees C for 7.5 months. For plasma specimens, 2.8% and 6.6% declines in theophylline were found with storage at 25 degrees C for 7 days or -20 degrees C for 6 months respectively, but no significant change was found in specimens stored at 6 degrees C for 7 days. Theophylline concentrations declined by 2.5% and 4.7% in saliva specimens stored at 25 degrees C and 6 degrees C for 7 days, respectively, but no decline was noted in specimens stored at -20 degrees for 6 months. Based on the observed decreases, the authors extrapolated that theophylline will decrease to 90% of its initial concentration after 15 days when spiked serum is stored at 25 degrees C, after 12 days with storage at 6 degrees C, and after 17 months with storage at -20 degrees C. For spiked plasma, theophylline concentrations will decrease to 90% of initial values after 11 days with storage at 25 degrees C, after 40 days at 6 degrees C, and after 4.5 months with storage at -20 degrees C. Theophylline concentrations will decrease to 90% of initial values in spiked saliva after 18 days at 25 degrees C, after 7.5 days at 6 degrees C, and after 17.5 months at -20 degrees C.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Small molecule HPLC Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Biospecimen Acquisition Biospecimen location Blood
Saliva
Storage Storage temperature 25 degrees C
6 degrees C
-20 degrees C
Storage Storage duration 1 day
2 days
3 days
4 days
7 days
1 month
2 months
3 months
6 months
7.5 months