Determination Of Nevirapine Plasma Levels By High Performance Liquid Chromatographic Method
View/ Open
Date
2013Author
Okalebo, Faith A
Oluka, Margaret N
Guantai, Anastasia N
Juma, Daniel
Type
PresentationLanguage
enMetadata
Show full item recordAbstract
Background:
Nevirapine (NVP) is a non-nucleoside reverse transcriptase
inhibitor (NNRTI) that is widely prescribed in resource limited settings as part
of first line antiretroviral therapy (ART). The quantification of antiretroviral
drugs in plasma is a valuable pharmacological tool since the NNRTI are known
to exhibit pharmacokinetic/pharmacodynamic (PK/PD) and pharmacokinetic/
toxicity relationships.
Thus characterization of the relationship between nevirapine plasma concentrations
and drug response is key to the optimization of ART. Pharmacokinetic studies
require accurate and precise analytical methods for the measurement of
antiretroviral drug concentrations to ensure that correct and meaningful data are
fed back into clinical care.
Objectives:
The main objective was to validate a simple, sensitive and rapid
method for the determination of nevirapine concentrations in human plasma
using a high performance liquid chromatographic (HPLC) method.
Methods:
Nevirapine and the internal standard (carbamazepine) were extracted
from plasma into ethyl acetate under basic conditions and evaporated to dryness.
The dried sample was reconstituted with methanol and 90 μL injected into the
chromatograph. Separation of the analytes was achieved on a C18 reversed
phase analytical column and detection was done at 282 nm. The mobile phase
consisted of acetonitrile and phosphate with a flow rate of 0.8 mL/min under
isocratic conditions. Method validation followed FDA guidelines.
Results:
The method was of good selectivity and specificity for nevirapine and
the internal standard (IS) with no interference from endogenous substances and
concurrent drugs. Calibration curves were linear over the range of 0.645 μg/mL
to 17.2 μg/mL (R2 = 0.93 – 0.997). Intra and inter-day precision (%CV) were
less than 10%. The absolute recoveries for the analytes (>96%) were consistent
and reproducible.
The carryover effects as well as the effects of hemolysis and freeze-thaw cycles
were all within acceptable limits.
Discussion:
The method employed a single step extraction procedure that made
it simple and rapid. The use of carbamazepine as the internal standard was
an advantage because it is readily available making the method suitable for
resource limited laboratories. The method has been employed in the field for the
determination of nevirapine plasma levels in HIV patients on various HAART
regimens containing lamivudine, stavudine, zidovudine and tenofovir.
The successful field application of this method is a testimony of its reliability
and future expansion is envisaged
Citation
Okalebo, Faith A.,Oluka, Margaret N.,Guantai, Anastasia N.,Juma, Daniel,;2013.Determination Of Nevirapine Plasma Levels By High Performance Liquid Chromatographic Method,paper presented at the 2nd Bi-ennual International Scientific Conference 2013, Nairobi Kenya.Publisher
University Of Nairobi