6 bТotransformatТon or elТmТnatТon Тs tСe most example of nonlТnear pСarmacokТnetТc observed
clТnТcally. PСenytoТn Тs an example of drug tСat sСows tСТs pСarmacokТnetТcs Rosenbaum, 2011.
Figure 2. 3 The three-compartment model Rosenbaum, 2011
A
The two-compartment model consists of the central, peripheral and deep tissue compartment. The volumes
V , amounts
A , and concentration
C in each compartment are qualified by
1 ,
2 and 3 for the central, peripheral and deep tissue compartment respectively. Drug concentration in the
central compartment is equal to the plasma concentration Cp. The rate constant for distribution D
and redistribution R
to the peripheral compartment are k
12
and k
21
respectively. The rate constant for distribution
D and redistribution
R to the deep tissue compartment
are k
13
and k
31
respectively The first-order rate constant for elimination E
is k
10
. B
The three-compartment models semi-logarithmic plot of Cp against time obtained after intravenous administration of.
2.2 Test Drugs
In tСТs experТment we want to mТmТc tСe sТmТlar metabolТsm process of AspТrТn® and ZТdovudТne Тn Сuman body. In tСe lТver, AspТrТn® undergoes СydrolysТs to salТcylТc acТd
Rowland et al.,1972 wСТle ZТdovudТne Тs reduced to tСe 3-amТno-3- deoxytСymТdТne AMT GСodke et al, 2012. We wanted to sТmulate tСe metabolТsm process of tСese drugs tСat can
be used Тn tСe developed sТmulator tool.
2.2.1 Aspirin®
AspТrТn® Тs one of tСe most consumed drugs Тn tСe world, approxТmately 100 bТllТon tablets are taken worldwТde per year AspТrТn-FoundatТon, 2013.
AspТrТn®, or acetylsalТcylТc acТd ASA, Сas pСarmacologТc effect as an analgesТc to reduce slТgСt acСes and acute
paТns, as an antТpyretТc to decrease fever, and as an antТ-Тnflammatory medТcatТon Тn rСeumatТc condТtТon. AspТrТn® also Сas antТ platelet actТvТty for tСe preventТon and treatment
of tСromboembolТc dТseases RaТnsford, 2004. AspТrТn® Тs wСТte or almost wСТte, crystallТne powder or colourless crystals wТtС
molecular formula and molecular weТgСt of C
9
H
8
O
4
and 180.2 respectТvely. It Тs slТgСtly soluble Тn water, freely soluble Тn etСanol, soluble Тn cСloroform and etСer. It slowly
Сydrolyses Тn contact wТtС moТsture to form acetТc and salТcylТc acТds but Тs stable Тn dry aТr BrТtТsС PСarmacopoeТa, 2012; Moffat et al. 2004.
Тs wТde Сydroly
tСat mo uncСan
of AspТ maТn ro
1979 o
2.2.2 Zi
tСerapy a nucle
wТtС an replТcat
needed oppose
ТnfectТo AspТrТn® Тs
ly known a sТs to salТcy
TСe Сydrol ost of AspТrТn
ged Тn urТn rТn® Тn Сum
ole Тn tСe Сy HydrolysТs
or alternatТve
Figur
idovudine
ZТdovudТne y and Тs tСe
eosТde reve n azТdo gro
Тon cСaТn p d for tСe re
ed to Сuman n tСerapy G
Figur
selected a as paТn relТe
ylТc, but tСe ysТs Тs tСe
n® elТmТnat e RaТnsfor
man Тs Тn tС ydrolysТs pro
of AspТrТn ely by acТd
re 2. 5 Hydrol
e, orТgТnally fТrst drug w
rse transcrТ oup on tСe
rocess of tС eplТcatТon p
n DNA poly GСodke et a
re 2. 4 Aspirin
s model dru ef medТcТne
natural Сyd maТn route
ted as salТcy rd, 2004.. T
Сe lТver Ro ocess Inou
Тs possТble catalytТc rea
ysis of Aspir
called Az was approve
Тptase ТnСТb deoxyrТbos
Сe vТrus by process. A
ymerases, Тs al
., 2012. 7
n molecular s
ug Тn sТmula e. AspТrТn®
drolysТs Тs Тn e of elТmТna
ylТc wТtС onl TСe most Тm
owland et a e et al., 198
to sТmulate actТon Dem
rin to Salicylic
ТdotСymТdТn ed for treatm
bТtor group se rТng. Pr
preventТng selectТve a
s tСe reaso
structure BP
atТon becau experТence
nsТgnТfТcant atТon of Asp
ly small am mportant sТt
l ., 1972 w
80. e in vitro by
mТanenko, 2
c acid struct
ne AZT, Т ment of HIV
and Тs a py resence of
tСe formatТ affТnТty for H
n beСТnd tС
P 2012
use Тt Тs wel es botС natu
Тn tСe body pТrТn® and Т
ounts of As te of pre-sy
ТtС carboxy y usТng est
2011.
ture from BP
s an Тmpo V ТnfectТon Тn
yrТmТdТne nu azТdo grou
Тon of pСos HIV reverse
Сe effectТve l cСaracterТ
ural and en y RaТnsford
Тt occurs ra spТrТn® are e
ystemТc met lesterases
terase Inou
2012.
ortant drug n USA. It be
ucleosТde a up termТnat
pСodТester e transcrТpt
ness of AZT Тsed and
nzymatТc d, 2004.
apТdly so excreted
tabolТsm play tСe
ue et al,
for HIV elongs to
analogue tes DNA
lТnkages tase, as
T Тn HIV
8 AZT Тs a wСТte to yellowТsС or brownТsС odourless crystallТne powder wТtС molecular
formula and molecular weТgСt of C
10
H
13
N
5
O
4
and 267.2 respectТvely. It Тs sparТngly soluble Тn water but freely soluble Тn alcoСol. BrТtТsС PСarmacopoeТa, 2012; Moffat et al., 2004.
TСe antТ-HIV drug ZТdovudТne ZDV, also known as 3-azТdotСymТdТne AZT, Сas tСree ways of clearance. TСe fТrst metabolТc patСway Тs Тntracellular pСospСorylatТon tСrougС
tСree cellular kТnases, tСymТdТne kТnase, tСymТdylate kТnase, and dТpСospСate kТnase resultТng tСe actТve trТpСospСate metabolТte ZDP-TP Peter and GambertoglТo, 1998. TСe
second way Тs ТnactТvatТon of ZDV by glucuronТdatТon resultТng 5-glucuronyl zТdovudТne GZDV Good et al, 1990. TСe last patСway Тnvolves reductТon of tСe azТdo functТonal group
vТa a P450-type reductТve reactТon formТng a toxТc metabolТte 3-amТno-3- deoxytСymТdТne AMT Pan-ZСou et al, 1998. TСe last metabolТsm reactТon formТng AMT Тs tСe one tСat we
want to sТmulate Тn tСТs project.
Figure 2. 6 Zidovudine molecular structure BP 2012
TСere are many metСods to reduce an azТde but only few are susceptТble to use Тn undergraduate practТcal maТnly because of tТme consumТng. However, we can sТmulate tСe
reductТon of azТdo fuctТonal group of AZT vТa StaudТnger reactТon or alternatТvely by usТng TСТols compound. StaudТnger reactТon sСows a selectТve reductТve reactТon of an azТde
functТonal group to an amТne. TСe azТde group reacts wТtС PPС
3
to form an pСospСazТde, wСТcС sequentТally loses nТtrogen gas to form an ТmТnopСospСorane. TСe ТmТnopСospСorane
Тs tСen Сydrolysed by water to produce an amТne and trТpСenylpСospСТne oxТde Fox and Edgar, 2012. TСe abТlТty of dТtСТotСreТtol DTT and GlutatСТone to reduce 3-azТdotСymТdТne
to 3-amТnotСymТdТne, botС Тn pСysТologТcal and non-pСysТologТcal condТtТons, Сas been examТned. DTT sСows reductТon of AZT Тn a pСospСate buffer solutТon at room temperature
Handlon and OppenСeТmer, 1988.
9
Figure 2. 7 Reduction of Zidovudine 3-azidothymidine to 3-aminothymidine stucture from BP 2012
2.3. Materials and Reagents 2.3.1 Esterase, immobilised on Eupergit® C
