DRUG DISCOVERY & 2 September 2010

Transcription

1 LC-MS/MS QUANTITATION IN DRUG DISCOVERY & DEVELOPMENT Ludmila Alexandrova 2 September

2 For personal use only. Please do not reuse or reproduce without the author s permission. 2

3 Presentation Outline Bioanalysis i and Metabolites in Drug Discovery and Development Case Study Quantification of Phthalates in Urine Conclusion 3

4 What is Bioanalysis? Bioanalysis employed for the quantitative determination of drugs and their metabolites in biological fluids, plays a significant role in the evaluation and interpretation of bioequivalence, i pharmacokinetic and toxicokinetic ti studies (Viswanathan c.t. et al. Workshop/conference Report, AAPS Journal 2007; 9 (1) Article 4) 4

5 Metabolites and Bioanalysis In Drug Development LI LO CCS CLS P1 P2 P3 Market Identify and profile animal metabolites In vitro In vivo (cold/c 14 ) Identify and profile human metabolites Bioanalytical methods In vitro In vivo (cold/c 14 ) P M Non-GLP method GLP: Good Laboratory Practice P: Parent M: Metabolite(s) GLP method The cost to bring a drug to the market is about $1.3 billion (US FDA, 2004) 5

6 MS Instrumentation of Choice Bioanalysis Triple Quadrupoles Most of the Quantitative Assays are Performed in Multiple Reaction Monitoring (MRM) Mode Metabolite Identification Ion Traps Q-Tofs Triple Quadrupoles 6

7 Bioanalysis in Drug Discovery Phase Scope Determine Concentrations/Exposures in Pharmacokinetic (PK), Pharmacodynamic (PD) Studies Requirements and Challenges Significant Throughput for the Screening Across Different Chemical Series Generic Assays are Preferred/Automated Method Development No Stable Isotope Internal Standard Unknown Compound/Metabolite Stability No QC Samples to Verify Method Performance 7

8 Bioanalysis in Preclinical Phase Scope Determine Concentrations/Exposures in Toxicokinetic Studies Using Validated d Assays to Evaluate Drug Safety Requirements and Challenges Full Validation Required Stability in Matrix Investigated Highly Regulated: Conducted According to Good Laboratory Practice (GLP) and Most Activities Should Follow Standard Operation Procedures (SOP) More Work for Troubleshooting and Validation to Produce Rugged and Robust assay Time Constraint: Validation Completed Before the Actual Study Starts Long-Term Use for Routine Analysis The Bioanalytical Assay Becomes a Part of Regulatory Submission (e.g. IND) 8

9 Bioanalysis in Clinical Phase Scope Determine Concentrations/Exposures in Clinical /Bioequivalence Studies (Phase 1 - Phase 3) Requirements and Challenges Assay Adjusted for Human Matrices (Plasma, Serum, Urine) Ultra-Sensitive Assay May be Required Novel Target is Pursued Microdosing Long-Term Usage is Desirable: Preferable to Use the Same Assay Through Phase 1 Phase 3 clinical studies Assay Flexibility with Regards to Concomitant Medications or Background Interferences Fast Turn Around for First in Man Studies 9

10 Analytical Approaches for Bioanalysis LC/Ultraviolet (UV)/Fluorescence Due to Low ( if any) Specificity of Detectors Not Much in Use for Over a Decade LC/MS Most of the Assays are Performed Using Triple Quadrupole Instruments Operating in Selected Reaction Monitoring i (SRM) Mode Ionization Techniques APCI More appropriate for Poorly Ionized Analytes Less Matrix Effect ESI With Biological Matrices ESI is Prone to Ionization Suppression/Enhancement Sample Purification is Required 10

11 Liquid Chromatography in Bioanalysis Role of Chromatography for Bioanalysis Changed Baseline Separation is Not Required Due to High Selectivity of MRM LC Remains an Important Method for Concentration of Analytes During Injection or Minimize Matrix Suppression Only in Selected Cases Separation of Analytes is Required Low Level of Detection Phase II Metabolites 11

12 Phase II Metabolites Interference Sample Name: "STD 1.00 ng/ml" Sample ID: "" File: "23JUL04SS-SET2.wiff" Peak Name: "RO " Mass(es): "418.1/376.0 amu" Comment: "" Annotation: "" Sample Index: 62 Sample Type: Standard Concentration: 1.00 ng/ml 5500 Calculated Conc: ng/ml Acq. Date: 07/23/04 Acq. Time: 10:55:52 52 PM Sample Name: "STD 1.00 ng/ml" Sample ID: "" File: "23JUL04SS-SET2.wiff" Peak Name: "[Dx] (IS)" Mass(es): "426.2/384.3 amu" Comment: "" Annotation: "" Sample Index: 62 Sample Type: Standard 8.0e4 Concentration: 1.00 ng/ml Calculated Conc: N/A 7.5e4 Acq. Date: 07/23/04 Acq. Time: 10:55:52 52 PM 7.0e Modified: No Bunching Factor: 2 Noise Threshold: 5.00 cps Area Threshold: cps Num. Smooths: 2 RT Window: sec Expected RT: min Sep. Width: 0.20 Sep. Height: 0.01 Exp. Peak Ratio: 5.00 Exp. Adj. Ratio: 4.00 Exp. Val. Ratio: 3.00 Use Relative RT: No Int. Type: Base To Base Retention Time: 3.58 min Area: counts Height: cps Start Time: min End Time: min Intensity, cps N-acetyl Modified: No Bunching Factor: 2 Noise Threshold: cps Area Threshold: cps Num. Smooths: 2 RT Window: 30.0 sec Expected RT: 3.50 min Sep. Width: 0.20 Sep. Height: 0.01 Exp. Peak Ratio: 5.00 Exp. Adj. Ratio: 4.00 Exp. Val. Ratio: 3.00 Use Relative RT: No Int. Type: Base To Base Retention Time: 3.52 min Area: counts Height: cps Start Time: 3.27 min End Time: 4.04 min Intensity, cps 6.5e4 6.0e4 5.5e4 5.0e4 4.5e4 4.0e4 3.5e4 3.0e4 2.5e4 2.0e4 ISTD e4 1.0e Time, min Time, min Sample Name: "STD 1.00 ng/ml" Sample ID: "" File: "23JUL04SS-SET2.wiff" Sample Name: "STD 1.00 ng/ml" Sample ID: "" File: "23JUL04SS-SET2.wiff" Peak Name: "RO " Mass(es): "376.0/158.1 amu" Peak Name: "[Dx] (IS)" Mass(es): "384.0/162.1 amu" Comment: "" Annotation: "" Comment: "" Annotation: "" Sample Index: 62 Sample Index: 62 Sample Type: Standard Sample Type: Standard 2.69 Concentration: 1.00 ng/ml Concentration: 1.00 ng/ml Calculated Conc: ng/ml e5 Calculated Conc: N/A Acq. Date: 07/23/04 Acq. Date: 07/23/ e4 Acq. Time: 10:55:52 PM 1700 Acq. Time: 10:55:52 PM 9.00e4 Parent 1600 ISTD1 Modified: No Modified: No 8.50e4 Bunching Factor: 2 Bunching Factor: Noise Threshold: 7.00 cps Noise Threshold: cps 8.00e4 Area Threshold: cps 1400 Area Threshold: cps Num. Smooths: 2 Num. Smooths: e4 RT Window: sec 1300 RT Window: 30.0 sec 7.00e4 Expected RT: min Expected RT: 2.68 min Sep. Width: Sep. Width: e4 Sep. Height: 0.01 Sep. Height: 0.01 Exp. Peak Ratio: Exp. Peak Ratio: e4 Exp. Adj. Ratio: 4.00 Exp. Adj. Ratio: e4 Exp. Val. Ratio: 3.00 Exp. Val. Ratio: 3.00 Use Relative RT: No 900 Use Relative RT: No 5.00e4 Intensity, cps Int. Type: Base To Base 800 Int. Type: Base To Base 4.50e4 Retention Time: 2.70 min Retention Time: 2.69 min 4.00e4 Area: counts 700 Area: counts Height: cps Height: cps 3.50e4 Start Time: min 600 N-acetyl Start Time: 2.50 min ISTD 2 End Time: min End Time: 3.17 min 3.00e e e e e Intensity, cps Time, min Time, min 12

13 Phase II Metabolites Interference 5.7e7 5.5e Parent Max. 5.7e7 cps. 5.0e7 XIC of +Q1: to amu from Sample 2 4.5e7 4.0e7 XIC of +Q1: 456 to amu from Sample 2 Intensity y, cps 3.5e7 3.0e7 2.5e7 N-Sulfate 4.56 XIC of +Q1: to amu from Sample 2 2.0e7 1.5e7 N-Acetyl 1.0e e Time, min 13

14 Sample Preparation Techniques in Bioanalysis Goal Increase Sensitivity and Selectivity Minimize Ion Suppression Concentrate t Sample Most Popular Techniques Protein Precipitation (PPT) Liquid-Liquid Extraction (LLE) Solid Phase Extraction (SPE) On line Off line 14

15 Case Study Scope Develop Bioanalytical Method for Quantification of Urinary Phthalate Metabolites Assay Requirements Urine Two Analytes Total Monoethyl Phthalate (MEP) (Free and Glucuronidated) Total Monobutyl Phthalate (MBP) (Free and Glucuronidated) Stable Isotope Labeled Internal Standards MEP and MBP Glucuronides are not available Lower Limit of Quantification LLOQ=5 ng/ml LC-MS/MS 15

16 Background People are routinely exposed to phthalates because of their wide use as industrial solvents and plasticizers Diethyl and dibutyl phthalates t are widely used in perfumes, cologne, soap, shampoo, nail polish and cosmetics Some phthalates t and their metabolites are responsible for reproductive and developmental toxicities in animals Phthalate monoesters and their respective metabolites used as urinary or serum biomarkers of phthalate exposure 16

17 Phthalate Metabolism In Humans, Phthalate diesters are metabolized to their respective monoesters which are partially glucuronidated Excreted through Urine and Feces O O O R Monoester Glucuronide O R O Gluc O O R O -Glucuronidase Phthalate Diester MEP: R=Ethyl MBP: R=Butyl Monoester 17

18 Challenges of the method Develop Hydrolysis procedure to determine total monoester amount Free monoester+congugated monoester Possible Matrix effect Needs to be pre-concentrated and purified before injection Off line SPE On-line SPE On-line SPE Procedure Implemented Silica based monolithic column for sample pre-concentration/purification Column: Chromolith Flash RP-18e column (4.5x25mm, Merck KGaA, Germany) Back-flush to Analytical column MS Column: Eclipse Plus, Phenyl Hexyl 2.1x150mm, 5um (Agilent) Mobile Phase: A (0.1% Acetic Acid in water); B (0.1% Acetic Acid in Acetonitrile) Adopted from literature: Kato K. et al. Anal. Chem., 2005, 77 18

19 LC-MS Conditions Mass spectrometer: Triple Quadrupole (Micromass Quattro) Ionization: ESI- Mode: MRM Injection Volume 50uL Compound Transition monitored Cone /Collision Energy Retention Time (min) MEP /22 ~3.43 MBP /18 ~4.22 IS MEP /19 ~3.43 IS MBP /20 ~

20 Selected Reaction Monitoring (MRM) Transition: m/z 193 m/z 77 Q1 Q2 Q3 CID GAS 20

21 ON-LINE SPE METHOD On-line SPE for pre-concentration and purification Column: Chromolith Flash RP- 18e column (4.5x25mm, Merck KGaA, Germany) Mobile Phase: A (0.1% Acetic Acid in water); B (0.1% Acetic Acid in Acetonitrile) SPE Column 21

22 SWITCHING VALVE POSITION 1 Inject (50-100uL) Load on Trap Column while Analytical column is Equilibrating 1 Minute in Position 1 Analytical Column-MS Load (Autosampler) Gradient Pump 2 Trap Column Load Gradient Pump 1 Waste 22

23 HPLC ANALYTICAL METHOD Column Eclipse Plus, Phenyl Hexyl 2.1x150mm, 5um (Agilent) Mobile Phase: A (0.1% Acetic Acid in water); B (0.1% Acetic Acid in Acetonitrile) 23

24 Switching Valve POSITION 2 Back Flush from Trap Column onto Analytical Column to Mass spectrometer 7 minutes in Position 2 Analytical Column-MS Autosampler Gradient Pump 2 Trap Column Elute Gradient Pump 1 Waste 24

25 5ng/mL Calibration Solution 5 ng/ml PakV_100804_24708_14 14 Sm (Mn, 2x3) 100 % MRM of 7 Channels ES > (13C4-MBP) 6.04e4 Area PakV_100804_24708_14 Sm (Mn, 2x3) MRM of 7 Channels ES > 76.9 (MBP) 646 MBP 7.36e3 Area % PakV_100804_24708_14 Sm (Mn, 2x3) MRM of 7 Channels ES > (13C4-MEP) e4 Area % PakV_100804_24708_14 Sm (Mn, 2x3) MRM of 7 Channels ES MEP > (MEP) e3 Area % Time 25

26 MEP/MBP Calibration Curves 5ng/mL ng/mL Injection volume: 50uL Compound name: MEP Correlation coefficient: r = , r^2 = Calibration curve: * x Response type: Internal Std ( Ref 4 ), Area * ( IS Conc. / IS Area ) Curve type: Linear, Origin: Exclude, Weighting: 1/x, Axis trans: None Residual MEP Some Amounts of MEP were Detected in Blank Urine (~ ng/ml) Response ng/ml ng/ml Some Amounts of MBP weredetected in Blank Urine (~5 40 ng/ml) Compound name: MBP Correlation coefficient: r = , r^2 = Calibration curve: * x Response type: Internal Std ( Ref 5 ), Area * ( IS Conc. / IS Area ) Curve type: Linear, Origin: Exclude, Weighting: 1/x, Axis trans: None dual Resid 10.0 MBP ng/ml sponse Res ng/ml

27 Case Study : Summary On-line SPE Method Implemented 122 Urine Samples Analyzed in 3 Runs Wide Range of Concentrations Detected Confirming Human Exposure to Phthalates MEP Concentration range: ng/ml MBP Concentration range: <5 200 ng/ml This Method Could be Used for Other Studies which Require Sample Pre-concentration and Purification 27

28 Conclusions Bioanalysis is an Integral Part of PK/TK/PD Characterization of New Compounds from Discovery Through Various Stages of Drug Development Leading to the Market LC-MS Triple Quadrupoles are Instruments of Choice for Quantification Method Development is Challenging and Exciting Part of the Drug Development Process Since Unique Compounds are Used and New Targets Investigated The Choice of Instrumentation and its Characteristics is Important, but it is Essential to Understand Chemical Properties of the Compounds to be Successful! 28

29 Acknowledgments SUMS Group Allis Chien Karolina Krasinska Pavel Aronov Chris Adams Maurizio Splendore Vincent & Stella Coates Foundation 29