Physicochemical Properties at Bayer HealthCare (Wuppertal) and Their Use in Medicinal Chemistry. Jörg Keldenich Nov

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1 Physicochemical Properties at Bayer HealthCare (Wuppertal) and Their Use in Medicinal Chemistry Jörg Keldenich ov PhysChem Forum 1

2 Contents Measured physico-chemical parameters Introduction of our laboratory Model systems for lipophilicity Solubility Use in medicinal chemistry Jörg Keldenich ov PhysChem Forum 2

3 Physicochemical Properties Measured Lipophilicity Membrane Affinity MA Plasma binding human serum albumin binding HSA rat serum albumin binding RSA pka pka Solubility screening in various buffers SL equilibrium in buffer equilibrium in galenic formulations Jörg Keldenich ov PhysChem Forum 3

4 Logistics for HT Physicochemistry Vial collecting rack BLJ input for sample identification Bar-coded vial for sample registration Jörg Keldenich ov PhysChem Forum 4

5 Data Handling by Laboratory Information and Management System (LIMS) Chemistry Laboratories Sample BAY/Prepno., Barcode, Scale of Lab.- Tests, Weight, Journal Molecular Weight, Principle investigator, Projekt, Comparison cma, chsa flag for bases or acids PDH PIX Solubility HSA-binding Membrane affinity Sampleregistration PIL-LIMS Results, Calibration Data Reports Rack Rackno. Position Barcode Roboter Bar-code scan Rack Methods LISSY Samplepreparation Sequences Area, Time LC/MS/MS Waters Quattro-Micro Archive MTP Jörg Keldenich ov PhysChem Forum 5

6 ur model system Solid-supported lipid membranes (TRASIL ) Jörg Keldenich ov PhysChem Forum 6

7 Why Use Membrane Affinity? 1. comparison with other lipophilicity descriptors 6.0 mlogp vs mlogma mlogma (Österberg) vs logma Bayer logp y = x R 2 = logma Österberg et al mlogp (Österberg) mlogp (Österberg) acid mlogd7.4 vs mlogma mlogp (Österberg) base logma Bayer mlogd logma Jörg Keldenich ov PhysChem Forum 7

8 Why use membrane affinity? 2. comparison with physiological membranes lipiophilicity vs MA erythrocytes y = x R 2 = y = x R 2 = lipophilicity MA measured 100 cpow ACD D7.4 cma MAery Influence of cholesterol content has to be considered Jörg Keldenich ov PhysChem Forum 8

9 Why use membrane affinity? Influence of cholesterol MA vs Molratio Lipid/Cholesterol MA Molration C. Tradum et al.:biophysical J Jörg Keldenich ov PhysChem Forum 9

10 Why use membrane affinity? Influence of cholesterol MA vs MA ERY MA measured with pure egg lecithin MA measured with cholesterol/egg lecithin ratio of y = x R 2 = y = x R 2 = MA Ery MA Ery Jörg Keldenich ov PhysChem Forum 10

11 Why use membrane affinity? Influence of cholesterol Influence on passive permeation expected to be strong flexibility of plasma membrane is strongly influence by cholesterol, content usually about 80 mol% of phospholipids content Influence on distribution expected to be low 80% of all membranes are intracellular with a cholesterol content about 4 mol% of phospholipids content Jörg Keldenich ov PhysChem Forum 11

12 Comparison of solubility methods precipitation all compounds small amounts fast analytics from powder selected compounds large amounts (two samples) specific analytics compound dissolved in organic solvent oversaturated solutions possible sensitive to morphology sensitive to purity sensitive to solvent impurities Jörg Keldenich ov PhysChem Forum 12

13 Comparison of solubility methods precipitation Dissolve compound in DMS (2mg/40µl) Add 10µl of this solution to 1000µl buffer (1% DMS) Shake for 24h at room temperature Centrifuge to get supernatant Establish LC/MS/MS method Measure calibration standards and probe from powder Weight an appropriate amount of compound as solid Add 1000µl buffer Shake for 24h at room temperature Centrifuge to get supernatant Establish LC/MS/MS method Measure calibration standards and probe Jörg Keldenich ov PhysChem Forum 13

14 Comparison of solubility methods EXAMPLES: Compound SL (precipitation) [mg/l] SL (from powder) [mg/l] Cpd 5 Cpd 6 Cpd 7 Cpd ± 0,2 0.5 ± 0,3 Cpd ± 1,2 1.3 ± 0.2 Cpd ± 3,8 4.2 ± 1.1 Cpd ± ± 0.1 mod I mod II mod B amorphous mod I mod II 0.8 ± ± 0.4 <0.1 < ± ± ± ± 0.08 <0.1 < ± ± 19 Jörg Keldenich ov PhysChem Forum 14

15 Comparison of solubility methods ame MLSTRUCTURE Yalkowsky (water) charged neutral compounds Solubility [mg/l]: comparison PIL vs literatue (Yalkowsky) Warfarin H H Primidone 500 H Cl H Metolazone S 60 H ifedipine 6 9 H Ketoprofen 140 H 275 PIL (buffer 6.5) 100 Cl Glyburide H S H H H Indomethacin Cl 10 charged compounds neutral compounds Cimetidine H S H H H Phenacetin Cl F Haloperidol H literature (water) Phenytoin H H H Ibuprofen Jörg Keldenich ov PhysChem Forum 15 Acetanilide 6300 H

16 Lessons learned from solubility comparisons method differences not really critical physical form very important differences between research and development result from: morphology differences impurities solvent content counter-ions and buffers are important when compound is charged in solution Jörg Keldenich ov PhysChem Forum 16

17 Case Histories: The Use of Physicochemical Properties Two different projects as examples: 1. Reducing lipophilicity and HSA binding to increase fraction unbound: erectile disfunction 2. Influence of solubility on in vivo efficacy: the HSV project Jörg Keldenich ov PhysChem Forum 17

18 Reducing Lipophilicity and Protein Binding to Increase Fraction Unbound Starting point: initial compound moderate effective IC50 PDE-5: 530nM DP1 compound: Vardenafil highly effective IC50 PDE-5: 2nM H H S Insufficient physicochemical properties: high membrane affinity: high protein binding: 1.7e-5 mol/l solubility: below detection limit fraction unbound: <1% no in vivo efficacy improved physicochemical properties: reduced membrane affinity: 580 reduced protein binding: 1.2e-4 mol/l solubility: 220 mg/l fraction unbound: 14% excellent in vivo efficacy Jörg Keldenich ov PhysChem Forum 18

19 Reducing lipophilicity and protein binding to increase fraction unbound Even the prediction of the in vivo effect from IC50 and fraction unbound (calculated from MA and HSA) was possible 1.E+02 initial compound Dose measured in vivo 1.E+01 1.E+00 1.E-01 Vardenafil 1.E-02 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 Dose calculated from IC 50 and physicochemical properties Jörg Keldenich ov PhysChem Forum 19

20 Influence of solubility on in vivo efficacy Starting point: Example 1 moderate activity IC50: 750nM survival % of HSV infected mice at 60mg/kg vs free serum normalized with IC H S S Physicochemical properties: Membrane affinity: 1430 protein binding: 2e-4 mol/l fraction unbound: 10% Solubility: 17mg/l survival % at 60mg/kg optimization of physicochemistry not necessary, activity has to be improved free serum/ic 50 Jörg Keldenich ov PhysChem Forum 20

21 Influence of solubility on in vivo efficacy Development candidate in vitro activity IC50: 20 nm survival % of HSV infected mice at 60mg/kg vs free serum normalized with IC Example 2: brilliant compound in vitro IC50: <1 nm 0.9 S Physicochemical properties: S H 2 Membrane affinity: 1590 protein binding: 1e-5 mol/l fraction unbound: 1% Solubility: 2.7mg/l good in vivo efficacy survival % at 60mg/kg free serum/ic50 S Physicochemical properties: H S Solubility: <0.1 mg/l excellent in vivo efficacy when administered as solution, no in vivo efficacy even as micronized powder Jörg Keldenich ov PhysChem Forum 21

22 Conclusion Impact of Physicochemistry Proven Physicochemistry/ADME Implemented in Medicinal Chemistry Properties Routinely Measured for Every Strategic Project Use in Lead ptimization and Exploratory Research Established Jörg Keldenich ov PhysChem Forum 22