Quantification in plasma

B.4.2.2 Nonbenzodlazeptnes GG-NPD was used by Kivisto et al. (1999) to quantitate the nonbenzodiazepine anxiolytic buspirone and its major metabolite, l-(2-pyrimidinyl)-piperazine, using separate extraction methods and separate assays. The hmit of quantification in plasma for both compounds was 0.2 ng/mL, which makes this assay useful for pharmacokinetic studies of this compound (Kivisto et al., 1999). A rapid, simple method for analysis of buspirone in rat brain requiring a single extraction step followed by GC-NPD has also been described (Lai. et al., 1997). 

The determination of sorafenib plasma concentrations was performed by HPLC onto a C8 column (4 min run time) [115] and C18 column (6 min run time) [116]. Similarly, HPLC C18 columns have been used for the quantification in plasma of lapatinib [117], vatalanib [119] (3 and 8 min run time, respectively), and also for bosutinib [88], whereas UPLC was used for the TKI in development of axitinib (1.2 min run time) [120],... 

Rochat B et al (2008) Imatinib metabolite profiling in parallel to imatinib quantification in plasma of treated patients using liquid chromatography-mass spectrometry. J Mass Spectrom... 

Chlorinated phenoxy acids, mass spectrometry, 78 Chlorine solution, 1169 Chlorisondamine chloride, xvii Chlorkresolum, 450 Chlormadinone acetate, 448 Chlor-Mal, 457 Chlormene, 457 Chlormethazanone, 449 Chlormethiazole, 448 quantification in plasma, 17 test for in plasma, 21 Chlormethiazole edisylate, 448 Chlormethiazole ethanedisulphonate, 448 Chlormethylencycline, 480 Chlormezanone, 449 Chloroacetanilide, 465... 

Ethazol, 985 Ethbenzamide, 590 Ethchlorvynol, 22,594 quantification in plasma, 17 test on stomach contents, 6 test on urine, 5 Ethebenecid, 595 Ethenzamide, 590 Ether, 595 Etherone, 598 Ethiazide, 595 Ethidium bromide, 661 Ethinamate, 596 Ethinyl estradiol, 596 Ethinylnortestosterone, 823 Ethinyloestradiol, 596 Ethinyloestradiolmethyl ether, 739 Ethinyltestosterone, 598 Ethiofencarb, 83 Ethionamide, 597 Ethionamide sulphoxide, 598 Ethirimol, 83 Ethisterone, 598 Ethocaine, 925 Ethoforme, 382 Ethofumesate, 83... 

Salicylates, test on blood, 6 test on stomach contents, 5 test on urine, 4 Salicylazosulphapyridine, 993 Salicylic acid, 26, 965 in horse urine, 96 (metabolite), 362, 763, 967 quantification in plasma, 26 Salicylic acid acetate, 361 Salicylideneisonicotinohydrazide, 966 Salicylosalicylic acid, 967 Salicyluric acid, 362, 966 Saligel, 965 Salinazid, 966 Salipran, 376 Salisulf, 993... 

Theophylline, 1011 in sport, 98 (metabolite), 421 quantification in plasma, 26 therapeutic drug monitoring, 110 Theophylline, anhydrous, 1011 Theophylline cholinate, 1011 Theophylline ethylenediamine compound, 1011 Theophylline hydrate, 1011 Theophylline monoethanolamine, 1011 Theophylline monohydrate, 1011 Theophylline olamine, 1011 Theophylline sodium aminoacetate, 1011 Theophylline sodium glycinate, 1011 Theophylline-7-acetic acid, 310 Theophylline-aminoisobutanol, 408 Theospan, 1011 Theovent, 1011 Thephorin, 880 Theralax, 397 Theralene, 1046 Therapav, 848... 

Dasi F, Lledo S, Garcia-Granero E, RipoU R, Marugan M, Tormo M, et al. Real-time quantification in plasma of human telomerase reverse transcriptase (hTERT) mRNA a simple blood test to monitor disease in cancer patients. Lab Invest 2001 81 767-9. 

Grebenstein, N. and J. Frank. 2012. Rapid baseline-separation of all eight tocopherols and tocotrienols by reversed-phase liquid-chromatography with a solid-core pentafluorophenyl column and their sensitive quantification in plasma and liver. J. Chromatogr. A 1243 39-46. 

J. A. Pascual and J. Sanagustin, Eully automated analytical method for codeine quantification in human plasma using on-line solid-phase extraction and high-perfomance liquid clrromatogi aphy with ulti aviolet detection , 7. Chromatogr. B 724 295-302 (1999). 

Agarwal et al. 1978), the quantification of these specific enzymes may indicate that exposure to endosulfan has occurred. Blood tests, such as decay curves for aminopyrine in plasma, which are semiquantitative indices of liver enzyme induction, have been used successfully in the past to demonstrate enzyme induction in pesticide-exposed workers. Because numerous chemicals found at hazardous waste sites also induce these hepatic enzymes, these measurements are not specific for endosulfan exposure. However, measurements of enzyme activity, together with the detection of the parent compound or its metabolites in tissue or excreta, can be useful indicators of exposure. All of these potential biomarkers require further verification in epidemiological studies. Further studies with focus on the development of methods to separate and measure the estrogenicity of endosulfan in in vitro assays would be valuable since these assays are more sensitive and discriminative than other conventional biomarkers. Preliminary results have been presented by Sonnenschein et al. (1995). 

As a more sensitive detection method, MS can be very useful in amino acid determinations. For example, S-carboxymethyl-(R) cysteine or SCMC, is a mucolytic agent used in the treatment of respiratory diseases. The development of a method utilizing high performance IEC and atmospheric pressure ionization (API) mass spectrometry to quantify SCMC in plasma has been described.66 This method is simple (no derivatization needed), rapid (inn time 16 min.), sensitive (limit of quantification 200 ng/mL in human plasma), and has an overall throughput of more than 60 analyses per day. API-MS was used successfully with IEC to determine other sulfur-containing amino acids and their cyclic compounds in human urine.67 IEC has also been used as a cleanup step for amino acids prior to their derivatization and analysis by gas chromatography (GC), either alone or in conjunction with MS.68 69... 

There are special problems in bioequivalency determinations when conventional pharmacokinetic studies are not possible. For example, when drugs are administered intranasally for direct treatment of receptors in the nasal mucosa, the concentration of drug in plasma may be below the limit of quantification. In such cases we are forced to attempt measurement of clinical response. The subjectivity and/or low precision of this type of study can be a serious problem. 

N9. Nuijens, J. H., Huijbregts, C. C., Eerenberg-Belmer, A. J., Abbink, J. J Strack Van Schijndel, R. J., Felt-Bersma, R. J., Thijs, L. G., and Hack, C. E Quantification of plasma factor Xlla-Cl-inhibitor and kallikrein-C-inhibitor complexes in sepsis. Blood 72, 1841-1848 (1988). 

Kern, D., et al. (1996). An enhanced-sensitivity branched-DNA assay for quantification of human immunodeficiency vims type 1 RNA in plasma. J. Clin. Microbiol. 34,3196-3202. 

Pachl, C., el al. (1995). Rapid and precise quantification of HTV-1 RNA in plasma using a branched DNA signal amplification assay. J. Acquir. Immune Defic. Syndr. Hum. Retrovirol. 8,446-454. 

A linear calibration curve for carvedilol in plasma was constructed over a range of 1 to 80 ng/mL. The correlation coefficient exceeded 0.999. Intra-day and inter-day coefficients of variation were 1.93 and 1.88%, respectively. The average carvedilol recovery was 98.1%. The limit of quantification was 1 ng/mL. This high-throughput method enabled the analysis of more than 600 plasma samples without significant loss of column efficiency. 

Thiols, protein or small molecular weight, can be S-nitrosated either by reaction with N O-oxidation products (Scheme 4.1) in hydrophobic domains of plasma proteins or transnitrosated at the cell-plasma interface of NO-producing cells (endothelial cells) or NO-storing cells (RBCs). Efforts to determine the true levels in plasma and in the various cellular compartments are complicated owing to thermal sensitivity and photosensitivity (Sexton et al., 1994 Alpert et al., 1997 Mutus et al., 1999) of the RS-NO bond. Techniques currently employed for the detection and quantification of RSNOs have been summarized in recent reviews (Martinez Riuz and Lamas, 2004 Rasaf et al., 2004). 

Bayliss and co-workers [10] combined ultra-high flow rates, parallel LC columns, a multiplex electrospray source, and mass spectrometric detection for the rapid determination of pharmaceuticals in plasma using four narrow bore (50 mm x 1 mm, 30 pm Oasis HLB) or capillary (50 mm x 0.18 mm, 25 pm Oasis HLB) HPLC columns with large particle sizes (to avoid high system back-pressure) in parallel with a multiple probe injector and a MUX MS interface. Small sample aliquots were injected directly into the system without sample pre-treatment procedure, obtaining very low limits of quantification (from 1 to 5 ng/mL). 

Kratzsch C, Peters FT, Kraemer T, Weber AA, Maurer HH. 2003. Screening, library-assisted identification and validated quantification of fifteen neuroleptics and three of their metabolites in plasma by liquid chromatography/ mass spectrometry with atmospheric pressure chemical ionization. J Mass Spectrom 38 283. 

Dai, G., Wei, X., Liu, Z., Liu, S., Marcucci, G., and Chan, K. K., Characterization and quantification of Bcl-2 antisense G3139 and metabolites in plasma and urine by ion-pair reversed phase HPLC coupled with electrospray ion-trap mass spectrometry. Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences 825(2), 201-213, 2005. 

The simultaneous identification and quantification in human plasma of 14 BB (atenolol, sotalol, diacetolol, carteolol, nadolol, pindolol, acebutolol, metoprolol, celiprolol, oxprenolol, labetalol, propranolol, tertatolol, and betaxolol) was achieved by Delamoye et al. [78] using LLE, RPLC C18 (250mmx4.6mmx5pm) separation using a gradient of acetonitrile-phosphate buffer pH 3.8 at a... 

An example of the use of GC with nitrogen selective detection is in the quantification of bupivacaine in plasma. Bupivacaine contains two nitrogen atoms in its structure which makes it a good candidate for this type of analysis. The limits of detection which can be achieved with a nitrogen selective detector for this compound are much better than methods based on flame ionisation detection, which are much less selective. 

CN128 Olsson, G., A. M. Ostlund-Lindquist, G. Bondjers, O. Wiklund, and S. O. Olofsson. Quantification of plasma lipids and apolipoproteins in British Halflop rabbits. A comparison between normocholesterolemic rabbits, hypercholesterolemic rabbits (modified WHHL rabbits) and rabbits fed an atherogenic diet. Atherosclerosis... 

An FIPLC method using electrochemical detection in the reductive mode for the determination of artemether 28a and its metabolite dihydroartemisinin 29a <1997JCFI(B)145> and for the simultaneous quantification of artesunate 31 and dihydroartemisinin 29a in plasma has been developed <1997JCFI(B)259, 1998JCFI(B)201>. An effective reversed-phase FIPLC method using electrochemical and UV detection has been developed for the simultaneous determination in plant extracts of artemisinin and its bioprecursors such as arteannuin B 32a, and artemisitene 27 <1995JNP798, 2001JIC489>. 

Greener JE, Poorthuis BJ, Kuijper S, Helmond MTJ, Hollak CE, Aerts JM (2007) HPLC for simultaneous quantification of total ceramide, glucosylceramide, and ceramide trihexoside concentrations in plasma. Clin Chem 53 742-747... 

Figure 25-8 Baseline separation of enantiomers of the drug Ritalin by HPLC with a chiral stationary phase. One enantiomer is pharmacologically active for treating attention deficit disorder and narcolepsy. The other enantiomer has little activity but could contribute to undesired side effects. Pharmaceutical companies are moving toward providing enantiomerically pure drugs, which could be safer than mixtures of optical isomers. [From R. Bakhtiar, L Ramos, and F. L. S. Tse, "Quantification of Methylphenidate in Plasma Using Chiral Uquid-Chromatography/Tandem Mass Spectrometry Application to Taxicokinetic Studies," Anal. Chim. Acta 2002, 469.261.]...

A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed [33] and validated for the determination of donepezil in human plasma samples. Diphenhydramine was used as the IS. The collision-induced transition m/z 380 > 91 was used to analyze donepezil in selected reaction monitoring mode. The signal intensity of the m/z 380 —> 91 transition was found to relate linearly with donepezil concentrations in plasma from 0.1 to 20.0 ng/ml. The lower limit of quantification of the LC/MS/MS method was 0.1 ng/ml. The intra- and inter-day precisions were below 10.2% and the accuracy was between 2.3% and +2.8%. The validated LC/MS/MS method was applied to a pharmacokinetic study in which healthy Chinese volunteers each received a single oral dose of 5 mg donepezil hydrochloride. The non-compartmental pharmacokinetic model was used to fit the donepezil plasma concentration-time curve. Maximum plasma concentration was... 

HPLC with column switching and mass spectrometry was applied to the online determination and resolution of the enantiomers of donepezil HC1 in plasma [38]. This system employs two avidin columns and fast atom bombardment-mass spectrometry (FAB-MS). A plasma sample was injected directly into an avidin trapping column (10 mm x 4.0 mm i.d.). The plasma protein was washed out from the trapping column immediately while donepezil HC1 was retained. After the column-switching procedure, donepezil HC1 was separated enantioselectivity in an avidin analytical column. The separated donepezil HC1 enantiomers were specifically detected by FAB-MS without interference from metabolites of donepezil HC1 and plasma constituents. The limit of quantification for each enantiomer of donepezil HC1 in plasma was 1.0 ng/ml and the intra-and inter-assay RSDs for the method were less than 5.2%. The assay was validated for enantioselective pharmacokinetic studies in the dog. 

Zarghi et al. [76] developed an HPLC method, using a monolithic column, for quantification of omeprazole in plasma. The method is specific and sensitive with a quantification limit of 10 ng/ml. Sample preparation involves simple, one-step extraction procedure, and analytical recovery was complete. The separation was carried out in reversed-phase conditions using a Chromolith Performance (RP-18e, 100 x 4.6 mm) column with an isocratic mobile phase consisting of 0.01 mol/1 disodium hydrogen phosphate buffer-acetonitrile (73 27) adjusted to pH 7.1. The wavelength was set at 302 nm. The calibration curve was linear over the concentration range 20-1500 ng/ml. The coefficients of variation for intra- and interday assay were found to be less than 7%. 

Erturk et al. [40] determined vigabatrin in human plasma and urine by HPLC after derivatization with 4-chloro-7-nitrobenzofurazan with fluorescence detection at 520 nm with excitation at 460 nm. A column (20 cm x 3.9 mm) of Shim-Pack Cig (5 /tm) with a mixture of 10 mM phosphoric acid-acetonitrile (60 40) as a mobile phase (flow rate 1.0 ml/ min) was used. The assay was rectilinear over the concentration range of 2.0-20.0 fig/ml for plasma and 1.0-15.0 yg/ml for urine. The lower limit of detection and the lower limit of quantification for vigabatrin were 0.1 and 0.2 /ig/ml, respectively, in plasma and urine. Both the within-day and day-to-day reproducibilities and accuracies were less than 5.46% and 1.6%, respectively. 

In the example of a-human atrial natriuretic peptide (ANP), found at increased plasma levels in patients with heart failure, Numata et al. [70] demonstrated how IPCR sensitivity accelerated conventional assay procedures. For individual treatment of the cardiac patients, a prompt detection of atrial distension by the presence of the ANP marker would be desirable. Common ANP tests, however, take 2-3 days for the quantification of plasma by radiometric or ELISA techniques. With sandwich IPCR, the assay time could be shortened to 5 hours. A good correlation between IPCR and radiometric detection was maintained, combined with an additional improvement of the detection limit to 2 ng/L ANP. The average level of ANP in plasma for 25 patients with heart failure was found to be 117 100 ng/L, significantly higher than the typical level of 20 14 ng/L for healthy subjects. 

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