Stability of phenytoin in blood collected in vacuum blood collection tubes.
The stability of phenytoin in blood collected in plain and serum separator tubes (SSTs) was investigated under simulated storage and transport conditions. The drug was generally more stable in plain collection tubes than in SSTs. No degradation occurred in plain red-top tubes or in refrigerated SSTs, but clinically significant degradation was present in SSTs stored at room temperature (25 degrees C) and at elevated temperature (32 degrees C) 24 h after collection. The mean loss was 17.9% at 25 degrees C and 25.9% at 32 degrees C. It is recommended that if blood is to be transported or stored in SSTs, the samples be refrigerated unless assay can be performed within 8 h.
Parish
R C
RC
Department of Pharmacy Practice, College of Pharmacy, University of Georgia, Athens 30602.
Alexander
T
T
D004349:Drug Packaging; D004355:Drug Stability; D006801:Humans; D010672:Phenytoin / Q000097:blood*; D013048:Specimen Handling; D013696:Temperature; D013997:Time Factors
D010672:Phenytoin