Prediction of Oral Absorption: 6-Fluoroquinolones

Transcription

1 Prediction of ral Absorption: 6-luoroquinolones Mª del Val Bermejo Sanz, Ph.D. Depto. armacia y Tecnología armacéutica acultad de armacia. Universidad de Valencia Valencia, España Strategies for ral Drug Delivery ral Absorption Regulation and Evaluation March 11-16, 2001 Garmisch Partenkirchen, Germany 1 Prediction of ral Absorption: 6-luoroquinolones Bioavailability prediction in drug development: fluoroquinolones. CICYT (SA ) Director: Prof. JM Plá Delfina Absorption-partition relationships Bioavailability predictions 2

2 Absorption-Partition Correlations ka1 lumen ka2 aqueous pathway membrane ka lumen membrane ka Aqueous layer Plasma ka Aqueous layer Plasma km P Ka = B + P a a kp C + d C + P ka km P Ka = B + P a a P J. Pharmacokin. Biopharm. 14(6), (1986) J. Pharmacokin. Biopharm. 15(6), (1987) P 3 Absorption-Partition Correlations ka lumen ka membrane Aqueous layer Plasma P Higuchi- Ho = + ka kaq kmem C P d Ka = 1+ E M P d Correlations in Colon or in Small intestine with Compounds MW>250 Journal of Pharmaceutical Sciences 84, (1995). 4

3 Absorption-Partition Correlations CH CH R R R= H, orfloxacin CH 3 CH R ame R R= H, Cyprofloxacin H CV CH 3 -CH 2 -CH 3 CV (CH 2 ) 2 -CH 3 CV CV (CH 2 ) 3 -CH 3 CV R= CH 3, CH 3 -(CH 2 ) n - n=1-5 Homologous Compounds CEAVISA S.A. Spain 5 Absorption-Partition Correlations H 2 H H H H CH Sparfloxacin Sarafloxacin CH lumequine C H S CEAVISA 8804 CEAVISA

4 Absorption-Partition Correlations Saturation Split -octanol buffer 24 h 50 r.p.m 22ºC Aliquot Quinolone solution A. Ruiz 7 Absorption-Partition Correlations Partition Coefficient: rganic Phase: n-ctanol Aqueous Phase: aqueous buffer solution at ph Phase Volume adjusted for each compound Saturation Dissolution of quinolone in aqueous phase Equilibrating during 24 h at 22ºC Analysis of the aqueous concentration by HPLC C P= C o a = ( Q Q ) ai Q af af /V /V a o 8

5 Absorption-Partition Correlations Absorption studies: Solutions of compounds on saline buffered at ph Concentration of each compound far enough of its Cs Perfused Volume: 10 ml 9 Absorption-Partition Correlations Closed Loop Perfussion Technique: Doluisio s Method Syringe Stopcock Samples Whole small intestine Bile ductclosed Water reabsorption measurement Gut Cannula 10

6 Absorption-Partition Correlations Closed Loop Perfussion Technique: Doluisio s Method Samples 11 Absorption-Partition Correlations Closed Loop Perfussion Technique: Doluisio s Method Samples 12

7 Absorption-Partition Correlations Closed Loop Perfussion Technique: Doluisio s Method 13 Absorption-Partition Correlations Water reabsorption correction V t A c = V = 0 A k t exp V V t 0 14

8 Absorption-Partition Correlations Absorption rate constant: A = A 0 e ka t Ln A ka, mean value of six animals time 15 Absorption-Partition Correlations Analysis: HPLC fluorimetric detection Method validation Stability of compound in luminal fluid 16

9 Absorption-Partition Correlations Absorption rate constant h orfloxacin homologous Partition coefficient, P Absorption rate constant h Cyprofloxacin homologous Partition coefficient, P Journal of Pharmaceutical Sciences 84, (1995). 17 Absorption rate constant h Absorption-Partition Correlations kaq = + ka kaq kmem kmem Partition coefficient, P Kaq (h -1 ) Kmem (h -1 )

10 Absorption-Partition Correlations Compound MIC 90 Compound MIC 90 orfloxacin 0.1 Ciprofloxacin Methylnorfloxacin 0.1 -Methylciprofloxacin Ethylnorfloxacin 0.2 -Ethylciprofloxacin Propylnorfloxacin 0.4 -Propylciprofloxacin 0.1 -Butylnorfloxacin 0.4 -Butylciprofloxacin 0.2 -Pentylnorfloxacin 0.4 -Pentylciprofloxacin 0.2 -Hexylnorfloxacin 1.6 -Hexylciprofloxacin 0.4 -Heptylnorfloxacin 3.2 -Heptylciprofloxacin 0.4 MIC 90 of the compounds against E. Coli ATCC Journal of Pharmaceutical Sciences 84, (1995). 19 Absorption-Partition Correlations Constante de Velocidad de Absorción, ka (h -1 ) 8 Wagner-Sedman it 6 Higuchi-Ho it CV CV CV CV CV e-3 1e-2 1e-1 1e+0 1e+1 1e+2 1e+3 1e+4 1e+5 1e+6 Coeficiente de reparto en n-ctanol Ana Ruiz-García. Ph.D Dissertation. University of Valencia. ovember

11 Absorption-Partition Correlations Quinolone ka-pred HH ka exp. ER% Ana Ruiz-García. Ph.D Dissertation. University of Valencia. ovember Absorption-Partition Correlations 2.00e e-4 CV 8804 lumequine CV 8919 P eff (cm/s) 1.00e e-5 CV orfloxacin derivatives Ciprofloxacin derivatives x x x10-3 1x x x10 0 1x x x10 3 1x10 6 n-ctanol Partition Coefficient Journal of Pharmaceutical Sciences (4) ,

12 Absorption-Partition Correlations : QSAR methodologies in drug absorption Instituto de Topología y Dinámica de Sistemas ITDYS. Université Paris VII. rance 1 CH 3 -CH CH 3 -CH 2 -CH 2 -CH CH 3 -CH-CH 3 CH A1-B11-C1 Vector A1 A2 B11 B12 C1 Traze A2 B12 Vizet P. PATQSAR. Version Journal of Pharmaceutical Sciences (4) , Absorption-Partition Correlations : QSAR methodologies in drug absorption 0.54C7 0.54C C5 0.54C C C C0 CH C CH CH 0 : 0.96 *C1 : 0.00 S 0.81 Lipophilicity -structure correlation Journal of Pharmaceutical Sciences (4) ,

13 Absorption-Partition Correlations : QSAR methodologies in drug absorption 0.35 C0 CH C6 0.14C4 0.14C C C C C CH CH 0 : 0.82 S 0.00 Absorption-structure correlation Journal of Pharmaceutical Sciences (4) , Absorption-Partition Correlations : QSAR methodologies in drug absorption CH C C C C C C C 2 o : 1.03 CH CH C C C C C C C 2 o : 0.33 CH Structure- antibacterial activity correlation Journal of Pharmaceutical Sciences (4) ,

14 Absorption-Partition Correlations CV Conc.(mg/mL) k a (h -1 ) DE V Ka (h -1 ) Concentration (µg/ml) Conc (µg/ml) V S S S S S S S S S S V S S S S S - Gonzalez I. et al.. V SEIG meeting, Valencia Absorption-Partition Correlations 8 ka in situ (h -1 ) Sparfloxacin 0 Sarafloxacin 1e-3 1e-2 1e-1 1e+0 1e+1 1e+2 1e+3 1e+4 1e+5 1e+6 n-ctanol partition coefficient, P ernández C. et al. V SEIG meeting, Valencia

15 Absorption-Partition Correlations Sarafloxacin Ka (h -1 ) Concentration (µg/ml) Conc(mg/mL) k a (h -1 ) DE Conc (µg/ml) S S S S S S S S S S - ernández C. et al. V SEIG meeting, Valencia STUDY THE ITESTIAL ABSRPTI CIPRLXACI I RATS. Absorption rate constant, ka, h n=6 n=6 n=9 igure 1 n= V 5 50 Ciprofloxacin concentration (µg/ml) Concentration in lumen ( µ g/ml) absence of V presence of V igure Time (min) Rodríguez M et al AAPS annual meeting 30

16 ILUECE P-GLYCPRTEI THE ITESTIAL ABSRPTI GREPALXACI. Absorption rate constant (ka, h n=6 * Whole intestine * Proximal fraction Medium fraction Distal fraction 0.3 mg/ml Grepafloxacin 0.01 mg/ml Grepafloxacin 0.01mg/mL Grepafloxacin mm Verapamil * Statistical differences igure 1 Sánchez-Castaño G. et al AAPS annual meeting Grepafloxacin donated by GLAX 31 Bioavailability prediction in drug development = a ( 1 E g ) ( 1 Eh) E g = gut or liver first pass effects E h = biliary excretion 32

17 Bioavailability prediction in drug development a a = 1 = 1 e ka T a B P e 1+ C M + P a T 33 Bioavailability prediction in drug development Administration (I.V.) Blood Samples Cannula jugular Vein ral Administration 34

18 Bioavailability prediction in drug development ral administration Group A (8-12 rats) I.V administration (bolus or perfusion) Group B (8-12 rats) Plasma sampling and Analysis AUC 0 t + (Trapezoidal rule) AUC 0 calculation AUC t ( C t /k) 35 orfloxacin plasma levels (mg/l) (1) Time (min) D iv =2 mg D oral =4 mg 36

19 Ciprofloxacin plasma levels (mg/l) D iv =4 mg D oral =4 mg Time (min) 37 4'- Propyl-ciprofloxacin plasma levels(mg/l) (3) D iv =4 mg D oral =4 mg Time (min) 38

20 Pefloxacin plasma levels (mg/l) (5) D iv =8 mg D oral =8 mg Time (min) 39 CH R 2 R 1 R 3 Molecular Tested quinolone Substituents in the formula Weight (M) P (n-octanol) k a (h -1 ) in situ R 1 R 2 R 3 orfloxacin Ethyl H H ± ±0.07 Pefloxacin Ethyl Methyl H ± ±0.18 Ethyl Propyl H ± ±0.40 Ciprofloxacin Cyclopropyl H H ± ± Propylnorfloxacin 4 -Propylciprofloxacin 3 -Methylciprofloxacin Cyclopropyl Propyl H ± ±0.52 Cyclopropyl H Methyl ± ±0.07 lumequine ccupied by a 1-8 ring Without 7-piperazinyl substituent ± ±

21 CV97102 in vivo Pefloxacin CV97100 Propil-or Propil-Cipro CV97104 lumequine 0.4 Ciprofloxacin orfloxacin ka in situ Journal of Pharmaceutical Sciences. 89(11) (2000) European Journal of Biopharmaceutics andpharmacokinetics. 48, (1999). Ana Ruiz-García. Ph.D Dissertation. University of Valencia. ovember Bioavailability prediction in drug development Predicted Correlation with ka values Experimental Predicted 42

22 Bioavailability prediction in drug development 8 6 Predicted Predictions from Higuchi-Ho eq T Experimental ka (h-1) e-3 1e-2 1e-1 1e+0 1e+1 1e+2 1e+3 1e+4 1e+5 1e+6 a BP a = 1 1+ C M+ P a e P- Lipophilicity 43 Conclusions 1. Lipophilicity seems to be the main factor governing quinolone absorption 2. A Partition coefficient in n-ctanol over 10 produces an absorption constant ~ 2 h -1 Peff ~ 1* 10-4 cm/s 3. Quinolones with a in situ permeability over 2*10-4 cm/s have a bioavailability aprox. 90%. 44

23 Conclusions 4. The absorption-partition relationship based on Higuchi- Ho equation has a good predictive performance at least with homologous quinolones; for heterologues compounds, the model is still able to predict the partition coefficient for maximum absorption. 5. The absorption rate constant ka determined in situ in rat is a good predictive parameter of oral bioavailability for the studied compounds. 6. The efflux processes observed in situ and in vitro have not a significant influence in vivo in rats at the oral doses used. 45 Work in progress 1. In vitro Permeability studies (Caco-2): Double Log-linear relationship Peff in situ-peff in vitro. Efflux process for some quinolones. 2. In situ absorption experiments of and at different concentrations: apparent active mechanism? 3. In vivo relevance of efflux. 4. In vitro metabolism of

24 Research Team Chairman: José M. Plá-Delfina. Ph. D. Professors M a del Val Bermejo Sanz. Ph.D. Teresa Garrigues Pelufo. Ph.D. Virginia Merino Sanjuán. Ph.D. Teaching assistants Gloria Sánchez Castaño Ph.D Ana Ruíz García Ph.D Ph.D candidates Carlos ernández Isabel González Ricardo alda Margarita Rodríguez 47