Navigation Links
Quantitation of a Dinitro Flavonoid (DNF) in Rat Plasma Using the Varian 1200L LC/MS/MS System

D. Garteiz, R. Morrow, and B. Alexander, TexMS Analytical Services, Houston, TX C.
Schmidt, Varian, Inc., Walnut Creek, CA

Introduction

Flavonoids are compounds that make up the pigments in fruits, vegetables, and herbs. There have been reports of flavonoids having multiple beneficial therapeutic effects for a large number of serious illnesses, such as rheumatoid arthritis, cancer, cataracts, anxiety, and depression. The objective of this work was to carry out a pharmacokinetic evaluation to determine a profile with the formulation being tested at increasing doses where there is pharmacological effect.

A Varian 1200L LC/MS/MS system was used for the quantitation for plasma levels of a novel dinitro-substituted flavone (DNF) in samples from a pharmacokinetic study following oral administration of the drug. Flavone was used as the internal standard. Structures are shown in Figure 1.

Instrumentation

Varian 1200L LC/MS/MS equipped with ESI source

Materials and Reagents

DNF provided by Faber-Kramer Pharmaceuticals, Houston, Texas.

Flavone (Catalog Number F602) from Sigma-Aldrich.

All other chemicals are reagent grade or HPLC grade.

Sample Preparation

A 200 μL aliquot of rat plasma containing DNF is spiked with 10 μL of flavone (0.2 ng) as the internal standard (ISTD). The rat plasma is made basic and extracted with hexane: chloroform (2:1, v/v).

After separation of the phases by centrifugation, the organic layer is transferred by pouring into a silanized conical tube and evaporated to dryness. The dry residue is reconstituted in 50 μL of methanol:water (60:40, v/v).

A 10 μL aliquot is injected into an ESI-LC/MS/MS for analysis using Selected Reaction Monito ring (SRM).

Results and Discussion

The ratio of the area intensities of the product ion for DNF to the product ion of the internal standard [(m/z 221)/(m/z 129)] is used to calculate the DNF concentration in unknown rat plasma samples. The calibration curve is generated from the analysis of a drug-free rat plasma matrix fortified with various amounts of DNF and a fixed amount of the internal standard. The calibration curve range for DNF is from 0.10 ng/mL to 5.00 ng/mL of rat plasma.

Figure 2 shows the excellent response and peak shape obtained at the Lower Limit of Quantitation (LLOQ) and Upper Limit of Quantitation (ULOQ). Visual examination of the calibration curve in Figure 3 shows that good linearity was obtained with the linear-log, curve-fitting model used. Additional sensitivity can easily be obtained by increasing the sample volume used for the assay.

Conclusion

The pharmacokinetic plot derived from DNF plasma levels obtained with six rats is shown in Figure 4. Visual observation of the plot reveals that at three hours post-dose there is a drop in DNF concentration, which rebounds an hour later, and from that point the concentration drops gradually in a linear fashion.

This fluctuation in concentration may be due to a phenomenon known as entero-hepatic recirculation. Enterohepatic recirculation is a process defined as a recycling of a drug through the liver by its excretion in bile, followed by reabsorption of the drug from the intestines into the portal circulation and passage back to the liver, where it is reexcreted in the bile.

Another possibility to explain the fluctuation in concentration is related to the limited solubility of DNF in aqueous media. DNF may be precipitating in the stomach and then later moving into the intestines where its absorption takes place. More studies are n eeded to determine if either of the processes described above are in fact taking place.

From the results of this study, it can be concluded that pharmacokinetic studies using the rat will be useful for comparison of different DNF formulations and different modes of administration.


'"/>

Source:


Page: All 1 2 3

Related biology technology :

1. Quantitation of Cabergoline at Extremely Low Plasma Concentrations with a Triple Quadrupole Mass Spectrometer
2. Bioanalytical Method Intraday Validation for the Quantitation of Paroxetine in Bovine Plasma using the TSQ Quantum Mass Spectrometer
3. Quantitation of the Protein MIA as a Marker for Chondrocytes in Research Samples
4. Comparison of Different Methods of mRNA Quantitation
5. Quantitation of DNA for Automated Sequencing Using the VersaFluor Fluorometer
6. Quantitation of RNA for Hybridization Blots Using the VersaFluor Fluorometer
7. Quantitation of Lymphangiogenesis Using the iCycler iQ Real-Time PCR Detection System and Scorpions Detection System, Rev A
8. Quantitation of GAD67 Gene Expression in Prefrontal Cortex of Schizophrenia Patients Using the iCycler iQ Detection System and Molecular Beacons, Rev A
9. Benchmark Plus Microplate Reader: Quantitation of Protein Concentration Using Two Different Colorimetric Assay Kits, Rev A
10. A Robust LC/MS/MS Method for the Quantitation of Very Long Chain Fatty Acids for Research into the Characterization of Peroxisomal Disorders
11. A new LC/MS/MS Research Method for Rapid Quantitation of Five Immunosuppressant Drugs, including Mycophenolic Acid (MPA)
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/23/2016)... ... 2016 , ... Charm Sciences, Inc. is pleased to announce ... Research Institute approval 061601. , “This is another AOAC-RI approval of the Peel ... President of Regulatory and Industrial Affairs. “The Peel Plate methods perform comparably to ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the sample ... the Arkansas State Crime Laboratory, has joined STACS DNA as a Field Application Specialist. ... said Jocelyn Tremblay, President and COO of STACS DNA. “In further expanding our capacity ...
(Date:6/23/2016)... NEW YORK , June 23, 2016 ... the trading session at 4,833.32, down 0.22%; the Dow Jones ... the S&P 500 closed at 2,085.45, down 0.17%. Stock-Callers.com has ... INFI ), Nektar Therapeutics (NASDAQ: NKTR ... BIND Therapeutics Inc. (NASDAQ: BIND ). Learn more ...
(Date:6/23/2016)... PUNE, India , June 23, 2016 /PRNewswire/ ... culture media market research report to its pharmaceuticals ... company profiles, product details and much more. ... market spread across 151 pages, profiling 15 companies ... now available at http://www.reportsnreports.com/reports/601420-global-cell-culture-media-industry-2016-market-research-report.html . ...
Breaking Biology Technology:
(Date:6/15/2016)... New York , June 15, 2016 /PRNewswire/ ... a new market report titled "Gesture Recognition Market by ... and Forecast, 2016 - 2024". According to the report, ... USD 11.60 billion in 2015 and is estimated ... reach USD 48.56 billion by 2024.  ...
(Date:6/7/2016)... -- Syngrafii Inc. and San Antonio Credit Union (SACU) ... Syngrafii,s patented LongPen™ eSignature "Wet" solution into SACU,s ... in greater convenience for SACU members and operational ... document workflow and compliance requirements. Logo ... Highlights: ...
(Date:6/2/2016)... 2016   The Weather Company , an IBM Business ... industry-first capability in which consumers will be able to interact ... questions via voice or text and receive relevant information about ... Marketers have long sought an advertising solution that can ... personal, relevant and valuable; and can scale across millions of ...
Breaking Biology News(10 mins):