Use of high-performance liquid chromatography to measure plasma concentrations of p-chlorophenoxyisobutyric acid after administration of clofibrate to humans

1977 ◽  
Vol 137 (1) ◽  
pp. 218-221 ◽  
Author(s):  
R.N. Woodhouse ◽  
D.G. Cresswell ◽  
L.F. Chasseaud ◽  
R.R. Brodie
1977 ◽  
Vol 23 (12) ◽  
pp. 2283-2287 ◽  
Author(s):  
G W Mihaly ◽  
J A Phillips ◽  
W J Louis ◽  
F J Vajda

Abstract We describe a modified high-performance liquid-chromatographic method for the simultaneous analysis of carbamazepine andits biologically active metabolite, carbamazepine-10, 11-epoxide. Concentrations of both these compounds in the plasma of 35 epileptic patients receiving chronic carbamazepine therapy are presented. Concentrations of carbamazepine in plasma were related to those of carbamazepine-10, 11-epoxide (r - 0.495, P less than 0.05). Total daily doses of carbamazepine were better correlated with plasma concentrations of carbamazepine-10, 11-epoxide (r = 0.714, P less than 0.001) than of carbamazepine (r = 0.269, P greater than 0.05). Close correlations were found between results of the three assay procedures we used to measure plasma carbamazepine concentrations: high-performance liquid chromatography, gas-liquid chromatography, and enzyme immunoassay. Correlation coefficients exceeded 0.97 and regression slopes were near unity, indicating that all three procedures were individually specific for the quantification of plasma carbamazepine.


2020 ◽  
Vol 58 (10) ◽  
pp. 915-921
Author(s):  
Sho Ohkubo ◽  
Yumiko Akamine ◽  
Tadashi Ohkubo ◽  
Yuka Kikuchi ◽  
Masatomo Miura

Abstract Here, we developed a novel high-performance liquid chromatography (HPLC) method for quantification of perampanel in clinical practice and investigated the relationships between the plasma concentrations of perampanel obtained by this HPLC method and the CYP3A4*1G polymorphism. The developed HPLC method was validated based on US Food and Drug Administration. The developed HPLC method could be performed with a plasma volume of only 200 μL and had a limit of quantification (LOQ) of 2.5 ng/mL. The coefficients of variation (CVs) for intra- and inter-day assays were less than 10.4 and 7.2%, respectively, and the accuracy was <2.4% for both assays. A total of 12 patients who received 2 mg perampanel had C0 values ranging from 70.5 to 451 ng/mL, and the CV showed a large variation of 51.4%. No correlations were observed between the dose-adjusted C0 and the CYP3A4*1G polymorphism. This method was superior to previously reported methods in terms of plasma volume and LOQ and was clinically applicable. Perampanel showed high variations in individual plasma concentrations; however, individual differences could not be predicted from analysis of the CYP3A4*1G polymorphism before perampanel administration. Therefore, after beginning perampanel treatment, the dose should be determined based on the observed plasma concentration.


2016 ◽  
Vol 7 (6) ◽  
pp. 239-247 ◽  
Author(s):  
L. Aït Moussa ◽  
O. El Bouazzi ◽  
S. Serragui ◽  
D. Soussi Tanani ◽  
A. Soulaymani ◽  
...  

Objective: High concentrations of antituberculosis (anti-TB) drugs can be associated with many adverse drug reactions (ADRs). The objective of this study was to examine the plasma concentrations of rifampicin (RMP) and isoniazid (INH) in patients with and without ADRs. Methods: Concentration monitoring data of patients treated with anti-TB drugs were retrospectively analyzed from 2009 to 2011. RMP and INH plasma concentrations were measured 2 and 3 h after drug administration respectively using high-performance liquid chromatography. Results: A total of 54 out of 120 patients have experienced ADRs to anti-TB drugs. The median concentrations [interquartile range (IQR)] obtained in patients with and without ADRs were 6.7 mg/l (3.7–9.9) and 5.6 mg/l (2.9–8.6) ( p = 0.56) for RMP and 4.3 mg/l (2.3–5.3) and 3.1 mg/l (1.7–4.8) ( p = 0.04) for INH, respectively. Related median doses (IQR) were 8.7 mg/kg (8.0–10.0) and 8.6 mg/kg (6.5–9.9) ( p = 0.42) for RMP and 4.8 mg/kg (4.3–5.0) and 4.0 mg/kg (2.8–5) ( p < 0.01) for INH, respectively. Concentrations above the expected range in patients with and without ADRs were not reached for RMP, but were 76% and 65% for INH, respectively. Correlation between concentrations and doses has not been established for RMP or INH. In addition, high INH concentrations showed no association with sex, age, liver injury or renal or diabetes. Conclusions: High INH concentrations were common in patients with and without ADRs whereas RMP concentrations were low or within the normal range in most patients. Further studies are required to assess the association between high INH concentrations and the occurrence of ADRs.


1989 ◽  
Vol 120 (2) ◽  
pp. 239-244 ◽  
Author(s):  
S. Lundin ◽  
A. Forman ◽  
Thomasz Rechberger ◽  
D. Svane ◽  
K. E. Andersson

Abstract. The regional distribution of immunoreactive OT and AVP in the human uterus was investigated. Specimens of non-pregnant human uterus and oviduct were homogenized and extracted. The tissue levels exceeded the plasma concentrations of the peptides. The largest quantities of both peptides were found in the cervix and oviductal isthmus. The amounts found in the uterine fundus and isthmus were, however, not significantly different. Only 23% of immunoreactive OT eluted in the position of standard peptide on high-performance liquid chromatography. All immunoreactive AVP eluted with standard AVP after additional ether extraction of octadecasilyl extracts. We conclude that the human uterus contains materials immunologically and chromatographically identical to oxytocin and vasopressin.


1978 ◽  
Vol 24 (12) ◽  
pp. 2166-2168 ◽  
Author(s):  
M A Peat ◽  
T A Jennison

Abstract We describe a routine method for determining plasma concentrations of quinidine by liquid chromatography. The procedure requires 1.0 ml of plasma (or serum) and involves internal standard addition, extraction with ether, and separation on a column of microparticulate silica. Day-to-day CV (15 days) was less than 5% and no deterioration in column performance has been observed during 12 months. Comparison with a fluorometric procedure gave a correlation coefficient of 0.995.


1990 ◽  
Vol 36 (8) ◽  
pp. 1436-1439 ◽  
Author(s):  
P Jatlow ◽  
H Nadim

Abstract We describe a procedure for measuring concentrations of cocaine in plasma by reversed-phase high-performance liquid chromatography, with ion-pairing. The procedure involves solvent extraction followed by back-extraction with dilute acid. The n-propyl ester of benzoylecgonine is used as an internal standard. An evaporation step is not required, and concentrations as low as 5 micrograms/L can be quantified. Plasma concentrations of cocaine determined by high-performance liquid chromatography correlated well with those determined by a previously reported gas-chromatographic procedure with nitrogen detection.


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