Effect of sample collection tubing type used in a clinical study on quantitation of pharmaceutical compounds in CSF by LC-MS/MS.
BACKGROUND
plasma/cerebrospinal fluid (CSF) ratio of compound K was determined to be lower than predicted during the conduct of clinical study. This triggered the evaluation of nonspecific binding of drug K and an additional ten compounds in CSF to collection tubing. Physiochemical properties such as pKa and log D values were correlated to the quantified results.


RESULTS
mean recoveries of compound K quality controls sampled within 24 h, as compared with spiked quality control, were 12.9, 44.4 and 77.7% from silicone, Tygon and Pharmed collection tubing, respectively. Eight out of ten compounds showed significant loss into silicone and seven out of ten compounds showed no significant loss into Pharmed.


CONCLUSIONS
silicone tubing is not recommended and Pharmed appears to be most appropriate. CSF sample collection tubing must be evaluated prior to starting clinical studies.
Bioanalytical Research, Drug Analysis Department (R46W), Abbott Labs GPRD, Development Sciences, 100 Abbott Park, IL 60064-3502, USA. azza.m.wagdy@abbott.com
Azza M
AM
Wagdy
Joseph C
JC
Kim
Grace E
GE
Kim
Huaiqin
H
Wu
Tawakol
T
El-Shourbagy
D035843:Biomedical Research; D002555:Cerebrospinal Fluid / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D004364:Pharmaceutical Preparations / Q000032:analysis / Q000134:cerebrospinal fluid*; D011786:Quality Control; D012828:Silicones / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013678:Technology, Pharmaceutical / Q000379:methods*
D004364:Pharmaceutical Preparations; D012828:Silicones