- Email: [email protected]
Pharmacokinetic and pharmacodynamic studies of full and partial agonists of adenosine A1 receptors
S86
341
343
CLINICAL PHARMACOKINETIC STUDIES OF FK 506 IN KIDNEY TRANSPLANT PATIENTS R. Casullo’, P. Brusa’, G. Squiccimarro*‘, P. Crosasso*, G. Segoloti** and L. Cattel. *Scuola di Specializrazione in Farmacia Ospedaliera - Dipartimento di Scienza e Tecnologia de1 Farmaco, Via P. Giuria, 9, 10125 Torino, Italy. **Uniti Trapianto Renale, Azienda Ospedaliera S. Giovanni Battista, Torino, Italy.
BIOEQIJIVALENCE OF 50 AND 100 pg LEVOTHYROXINJZ TABLETS ADMINISTERED IN STEADY STATE IN TARGET POPULATION
CeruUi R. (1) *, Rivolta G. (1), Cavalieri L. (2), Di Giulio C. (l), Vago T. (3), Baldi G. (3), Marzo A. (4). (I)
direzione
S.p.A.
medica
(3) scrvizio
20157
Milan,
ctici and (2) direzione
di endocrinologia,
Italy
(4)
operativa
Orpedale
I.P.A.S.
SA,
galenica
Luigi
Via
Sacco,
Ma&i,
e OTC,
via G.B. 6853
Bracco
Grassi
74,
Ligometto,
Switzerlaud.
FK 506 is a macrolide lactonc of fimgal origin with strong immunosuppressive properties. It acts by inhibiting the calcineurin intracellular phosphatase, resulting in the suppression of the production of interleukin-2 (IL-2), and the expression of IL-2 receptors on activated T cells. The cytochrome P450 3A4 in the liver is preliminary responsible for its metabolism. FK 506 is used to prevent organ rejection in kidney transplant patients. Its adverse effects include nephrotoxicity, gastrointestinal tract complaints and neurotoxicity. Monitoring blood FK 506 concentration helps in differential diagnosis of graft rejection and drug toxicity. Therefore, FK 506 concentrations in human whole blood of treated patients, with suspected very low level of FK 506, have been analised in this study. A range of appearance of “time to peak” and a “metabolism effect” have been evaluated, using a sensitive ELISA method (PRO-TR4C II@ - Incstar). A comparison of two methods (the above cited and Tacrolimus I - Abbott) routinely used for FK 506 analysis was also executed. Phannacokinctic studies have show the presence of inter- and intra-individual differences in FK 506 kinetics in organ transplant patients. Moreover, comparison of these methods has shown that PRO-TRAC Ilg, is a very sensitive method especially when it is necessary to monitor lowest or highest concentrations of FK 506. This study is supported by a fellowship from Azienda Ospedaliera S. Giovanni Battista, Torino, Italy.
all the
four
hormones
tested
and
with
both
the
strengths
administered.
and 100 vg can thus be declared interchangeable with the hvo references.
The
two
test
formulations
in
50
Key words: Lovothyroxine - LcvotriiodothJroninc concenlration - Biocquivalence. *: To whom correspondence should bc addressed.
-
Serum
344
342 BIOEQUIVALENCE PARACETAMOL
OF ACETYLSALICYLIC ACID AND ASSOCIATED IN TWO ORAL
FORMULATIONS A. Mar&‘,
”
Ns-,
Tettamanti”,
, M.R.
S. Ismar
” IPAS
SA,
2) I.S.I.
S.p.A.,
Two
Two parallel trials canicd out with levothyroxine 50 and IO0 &day (50x2 pdday or 100x1 &day) in repeated dose regimen. In each trial 20 patients suffering from primary hypothyroidism in treatment with 100 @day of thyroxine were enrolled. They were clinically and chemically euthyroid. Each trial lasted 114 days: 57 days devoted to the first treatment (test or reference) and 57 days to the other (reference or test). The test is a new formulation prepared with a technological improvement that is being to replace the reference. Serum concentrations of Isvothyroxine, free and total, and triiodothyronine, free and total, were assayed repeatedly during the treatment and in timed samples afier the last dose of each formulation, using radioimmunoassays. Cmax and AUCss, T were considered the target parameters for the bioequivalence which was assessed through the 90% confidence inlervals in the 0.80 - 1.25 range, as requested by EU and US FDA operating guidelines. The bioequivalence was fully assessed with Cmax and AU&s, 7, with
Via Masfri,
were
concentrations
moiety)
and
detection
in
55020
Lucca,
tablets single
dose
of salicylic
acid
and the other as tablets
lo
hveIve
volunteers,
six
two-sequence crossover contained 275 mg of
and 25 tug of caffeine. (SA,
of test and reference
intervals
(CI)
which
were
expression
of the salicylate
with the non-parametric test
compared
through
of
SA.
Time
Kmskal-Wallis
did
test, as eqected,
which,
not
The
is that
any tablets)
safety
problem.
is bioequivalent
of extent of absorption.
conclusion
with thereference
AUCS range
to peak processed not
statistically significant difference. The absorption rate was faster with involve
the 90%
ranged in the 0.80-l 25 range with CIs were comprised In the 0.70-1.43
of both the analytes. With C,, with P and on the borderline of this range with
Scatturin Department of Pharmaceutical Sciences, iDepartment of Experimental and Clinical Medicine. via Fossato di Mortara 19. 44100 Fez-ram, Italy; ‘Leiden Amsterdam Center for Drug Research, P.O. Box 9502. 2300 RA L&den, The Vetherlands
after dosing.
and AUC
confidence
effervescent
Aleotti
Italy
(test)
according to a MO-period, Both the formulations
R.
paracetamol 8) were evaluated with a HPLC method with UV validated for this kind of investigationsiu timed samples drawn
over a 24 h period C mu., I_
Pascoli,
175 mg of paracetamol
Plasma
P. Mazzucchelli”,
Switzerland
administered
acid,
Bo”,
Ligometto,
one as effervescent
males and six females, design with wash-out acetylsakylic
Dal
JosC S. Franzone”
Castelvecchio
formulations,
(reference)
6853
L Uhr”,
PHARMACOKINETIC AND PHARMACODYNAMIC STUDIES OF FULL AND PARTIAL AGONISTS OF ADENOSINE Al RECEPTORS ~&Q&k B. Pavan*, P.A. Borea5. K. Varanig. A.P. IJzerman* and A.
produce
any
however
does
the
(in tablets)
test
(in
in terms
The structure-activity relationships of adenosine NC-substituted (full agonists) and deoxyribose foartial agonists) derivatives were investinated with ‘kspect to their stibility. in’virro. in rat blood. A lhennodynamic Galysis of the binding of Ihc same compounds to rat brain adenosine Al receptors was performed. As for pharmacokinetic studies, the samples were incubated at 37°C m fresh whole blood and at regular time intervals aliquots were hemolyred in ice-cold water. The samples extracted were analyzed with reverse-phase highperformance liquid chromatography (HPLC). As for pharmaccdynamic studies the thermodynamic parameters AGO (standard free energy), AH” (standard enthalpy) and AS” (standard entropy) of the binding equilibrium were determined by means of affinity measurements carried auf at different temperatures (0. IO, 20. 25, 30°C). Affinity constants were obtained from inhibition assays on membrane
preparations
cyclohexyladenosine) affinity consrants cyclopentyladenosine)
of rat brain by use of the agonist as selective
were
adenosine
A]
receptor
[3H]CHA
( [3~]N6.
radioligand.
[3H]CHA
obtained from saturation experiments. CPA (N6was degraded (t]/2=24 f 2 min) in rat blood, whereas
CHA and 2’ or 3’-deoxyrlbose derivatives of CPA bmding of CPA and CHA war torally entropy-driven
and CHA were not. The with KD values (25°C) of
0.05 f 0.001 and 1.0 f 0.03 nM. respecuvely. The binding of 2’ or 3’. deoryribose derivalives was tolally entropy-driven although their affinity to adenosine Al receptor was decreased I2 - 7500 times with respect to the parent compounds. We conclude that structural modifications of the N6- amino group and the modifications of the ribose moiety of adenosine derivatives does not impede that adenosine derivatives interact with adenosine Al receptors. In this case only the affinity changes. but the molecular mechanism of the binding, as inchcared by thermodynamic data. does not. However the structural modifications strongly affect the degradation rare of the adenosme derivatives. In fact. only CPA IS sipmticantly degraded in rat blood.
341
343
CLINICAL PHARMACOKINETIC STUDIES OF FK 506 IN KIDNEY TRANSPLANT PATIENTS R. Casullo’, P. Brusa’, G. Squiccimarro*‘, P. Crosasso*, G. Segoloti** and L. Cattel. *Scuola di Specializrazione in Farmacia Ospedaliera - Dipartimento di Scienza e Tecnologia de1 Farmaco, Via P. Giuria, 9, 10125 Torino, Italy. **Uniti Trapianto Renale, Azienda Ospedaliera S. Giovanni Battista, Torino, Italy.
BIOEQIJIVALENCE OF 50 AND 100 pg LEVOTHYROXINJZ TABLETS ADMINISTERED IN STEADY STATE IN TARGET POPULATION
CeruUi R. (1) *, Rivolta G. (1), Cavalieri L. (2), Di Giulio C. (l), Vago T. (3), Baldi G. (3), Marzo A. (4). (I)
direzione
S.p.A.
medica
(3) scrvizio
20157
Milan,
ctici and (2) direzione
di endocrinologia,
Italy
(4)
operativa
Orpedale
I.P.A.S.
SA,
galenica
Luigi
Via
Sacco,
Ma&i,
e OTC,
via G.B. 6853
Bracco
Grassi
74,
Ligometto,
Switzerlaud.
FK 506 is a macrolide lactonc of fimgal origin with strong immunosuppressive properties. It acts by inhibiting the calcineurin intracellular phosphatase, resulting in the suppression of the production of interleukin-2 (IL-2), and the expression of IL-2 receptors on activated T cells. The cytochrome P450 3A4 in the liver is preliminary responsible for its metabolism. FK 506 is used to prevent organ rejection in kidney transplant patients. Its adverse effects include nephrotoxicity, gastrointestinal tract complaints and neurotoxicity. Monitoring blood FK 506 concentration helps in differential diagnosis of graft rejection and drug toxicity. Therefore, FK 506 concentrations in human whole blood of treated patients, with suspected very low level of FK 506, have been analised in this study. A range of appearance of “time to peak” and a “metabolism effect” have been evaluated, using a sensitive ELISA method (PRO-TR4C II@ - Incstar). A comparison of two methods (the above cited and Tacrolimus I - Abbott) routinely used for FK 506 analysis was also executed. Phannacokinctic studies have show the presence of inter- and intra-individual differences in FK 506 kinetics in organ transplant patients. Moreover, comparison of these methods has shown that PRO-TRAC Ilg, is a very sensitive method especially when it is necessary to monitor lowest or highest concentrations of FK 506. This study is supported by a fellowship from Azienda Ospedaliera S. Giovanni Battista, Torino, Italy.
all the
four
hormones
tested
and
with
both
the
strengths
administered.
and 100 vg can thus be declared interchangeable with the hvo references.
The
two
test
formulations
in
50
Key words: Lovothyroxine - LcvotriiodothJroninc concenlration - Biocquivalence. *: To whom correspondence should bc addressed.
-
Serum
344
342 BIOEQUIVALENCE PARACETAMOL
OF ACETYLSALICYLIC ACID AND ASSOCIATED IN TWO ORAL
FORMULATIONS A. Mar&‘,
”
Ns-,
Tettamanti”,
, M.R.
S. Ismar
” IPAS
SA,
2) I.S.I.
S.p.A.,
Two
Two parallel trials canicd out with levothyroxine 50 and IO0 &day (50x2 pdday or 100x1 &day) in repeated dose regimen. In each trial 20 patients suffering from primary hypothyroidism in treatment with 100 @day of thyroxine were enrolled. They were clinically and chemically euthyroid. Each trial lasted 114 days: 57 days devoted to the first treatment (test or reference) and 57 days to the other (reference or test). The test is a new formulation prepared with a technological improvement that is being to replace the reference. Serum concentrations of Isvothyroxine, free and total, and triiodothyronine, free and total, were assayed repeatedly during the treatment and in timed samples afier the last dose of each formulation, using radioimmunoassays. Cmax and AUCss, T were considered the target parameters for the bioequivalence which was assessed through the 90% confidence inlervals in the 0.80 - 1.25 range, as requested by EU and US FDA operating guidelines. The bioequivalence was fully assessed with Cmax and AU&s, 7, with
Via Masfri,
were
concentrations
moiety)
and
detection
in
55020
Lucca,
tablets single
dose
of salicylic
acid
and the other as tablets
lo
hveIve
volunteers,
six
two-sequence crossover contained 275 mg of
and 25 tug of caffeine. (SA,
of test and reference
intervals
(CI)
which
were
expression
of the salicylate
with the non-parametric test
compared
through
of
SA.
Time
Kmskal-Wallis
did
test, as eqected,
which,
not
The
is that
any tablets)
safety
problem.
is bioequivalent
of extent of absorption.
conclusion
with thereference
AUCS range
to peak processed not
statistically significant difference. The absorption rate was faster with involve
the 90%
ranged in the 0.80-l 25 range with CIs were comprised In the 0.70-1.43
of both the analytes. With C,, with P and on the borderline of this range with
Scatturin Department of Pharmaceutical Sciences, iDepartment of Experimental and Clinical Medicine. via Fossato di Mortara 19. 44100 Fez-ram, Italy; ‘Leiden Amsterdam Center for Drug Research, P.O. Box 9502. 2300 RA L&den, The Vetherlands
after dosing.
and AUC
confidence
effervescent
Aleotti
Italy
(test)
according to a MO-period, Both the formulations
R.
paracetamol 8) were evaluated with a HPLC method with UV validated for this kind of investigationsiu timed samples drawn
over a 24 h period C mu., I_
Pascoli,
175 mg of paracetamol
Plasma
P. Mazzucchelli”,
Switzerland
administered
acid,
Bo”,
Ligometto,
one as effervescent
males and six females, design with wash-out acetylsakylic
Dal
JosC S. Franzone”
Castelvecchio
formulations,
(reference)
6853
L Uhr”,
PHARMACOKINETIC AND PHARMACODYNAMIC STUDIES OF FULL AND PARTIAL AGONISTS OF ADENOSINE Al RECEPTORS ~&Q&k B. Pavan*, P.A. Borea5. K. Varanig. A.P. IJzerman* and A.
produce
any
however
does
the
(in tablets)
test
(in
in terms
The structure-activity relationships of adenosine NC-substituted (full agonists) and deoxyribose foartial agonists) derivatives were investinated with ‘kspect to their stibility. in’virro. in rat blood. A lhennodynamic Galysis of the binding of Ihc same compounds to rat brain adenosine Al receptors was performed. As for pharmacokinetic studies, the samples were incubated at 37°C m fresh whole blood and at regular time intervals aliquots were hemolyred in ice-cold water. The samples extracted were analyzed with reverse-phase highperformance liquid chromatography (HPLC). As for pharmaccdynamic studies the thermodynamic parameters AGO (standard free energy), AH” (standard enthalpy) and AS” (standard entropy) of the binding equilibrium were determined by means of affinity measurements carried auf at different temperatures (0. IO, 20. 25, 30°C). Affinity constants were obtained from inhibition assays on membrane
preparations
cyclohexyladenosine) affinity consrants cyclopentyladenosine)
of rat brain by use of the agonist as selective
were
adenosine
A]
receptor
[3H]CHA
( [3~]N6.
radioligand.
[3H]CHA
obtained from saturation experiments. CPA (N6was degraded (t]/2=24 f 2 min) in rat blood, whereas
CHA and 2’ or 3’-deoxyrlbose derivatives of CPA bmding of CPA and CHA war torally entropy-driven
and CHA were not. The with KD values (25°C) of
0.05 f 0.001 and 1.0 f 0.03 nM. respecuvely. The binding of 2’ or 3’. deoryribose derivalives was tolally entropy-driven although their affinity to adenosine Al receptor was decreased I2 - 7500 times with respect to the parent compounds. We conclude that structural modifications of the N6- amino group and the modifications of the ribose moiety of adenosine derivatives does not impede that adenosine derivatives interact with adenosine Al receptors. In this case only the affinity changes. but the molecular mechanism of the binding, as inchcared by thermodynamic data. does not. However the structural modifications strongly affect the degradation rare of the adenosme derivatives. In fact. only CPA IS sipmticantly degraded in rat blood.