Determination of drug concentration

Determination of drug concentration

Determination of drug concentrations in biological matrices is conducted for developing drugs to evaluate the pharmacokinetics through non-clinical and clinical studies, and for existing drugs as a control or monitoring purpose.

Mediford Corporation conducts determination of drug concentrations in pharmaceutical development such as non-clinical PK/TK analysis and clinical PK analysis.

Service details

Determination of drug concentration in biological matrix

PK/TK analysis

It is conducted following the validated method in accordance with Good Laboratory Practice (GLP). Pharmacokinetics (PK) analysis is conducted in GLP accredited laboratories through non-clinical and clinical stages. Toxicokinetics (TK) studies can be conducted in the same GLP system as that in the toxicity studies. We have extensive experience with a variety of animals. Calculation of TK/PK parameters and multisite studies can also be provided. Sample analysis with an appropriately validated method is conducted for the purpose of not only drug pharmacokinetics in blood, but bioavailability studies, bioequivalence studies, and drug interaction studies.

Various platform for drug determination

A large variety of analytical methods including LC-MS/MS and Ligand-Binding Assay (LBA) are used for determination.

For LS-MS/MS method, we have introduced a high-sensitivity mass spectrometer, SCIEX Triple Quad 7500 QTRAP Ready, to provide high-sensitivity analytical services. It performs measurements at higher sensitivity than conventional equipment for not only small molecules, but also for middle size molecules like peptides or nucleotides.

As for LBA, we have introduced MESO QuickPlex SQ120 from Meso Scale Diagnostics (MSD), and it provides high sensitivity determination with Electrochemiluminescence (ECL). It is used for determination of large molecule pharmaceuticals such as protein formulations and antibody drugs and performs measurement using the Hybridization assay method for analysis of nucleic acid drugs.

We have also introduced Gyrolab xP workstation from Gyros as an automated immunoassay system. By integrating analysis Wizard/Method for LBA among multiple laboratories, it is possible for us to be assigned as one of the analysis sites in multinational clinical trials.

For complicated modalities such as Antibody-Drug Conjugate (ADC), it is often effective to employ multiple platforms separately for each component. For example, by using LC-MS/MS for released drugs (payload), LBA with Gyrolab for antibodies (or whole drug), and ECL for anti-drug antibodies, each analysis can be optimized.

LC-MS/MS
LC-MS/MS
MESO QuickPlex SQ120/MS
MESO QuickPlex SQ120
Gyrolab xP workstation
Gyrolab xP workstation

Determination of anti-drug antibody

It is important to evaluate immunogenicity of dosing agents in development of pharmaceuticals. Immunogenicity refers to a property of inducing immunoreaction in vivo and producing anti-drug antibodies (ADA) is a typical example. Anti-drug antibodies include Neutralizing antibodies (NAb) which not only have binding ability to target components but also neutralizing activity decreasing the effectiveness of target components.

A tiered approach has been adopted for evaluating anti-drug antibodies, which involves screening assays, confirmatory assays, and characteristic analysis (neutralizing activity, titer) conducted in that order.
For screening assays and confirmatory assays, the methods often used are Bridging method using ECL by MSD, or Solid phase extraction with acid dissociation (SPEAD) that includes addition of acid to decrease the effect of coexisting drugs.
We also offer cell-based assays and competing ligand binding assays without cells known for determining neutralizing activity.

Mediford Corporation offers a series of analytical services through non-clinical to clinical studies.

Metabolite screening

Metabolite screening service with an accurate mass spectrometer is available. In addition to small molecules, middle size molecules like peptides or nucleotides are also on the analysis menu. We can conduct an analysis in accordance with “Standards for the Reliability of Application Data”.

Metabolic stability

Metabolic stability is evaluated with mass chromatogram and UV chromatogram of study compounds.

Profiling

Profiling is conducted with mass chromatogram of the molecular formula of predicted metabolites and UV chromatogram.

Estimation of structure

Metabolic change is estimated with accurate mass from MS spectrum, and metabolic change site is estimated with MS/MS spectrum pattern.

Identification of metabolites

Identification is conducted by comparison between standard reagents and metabolites in the sample, and retention time, MS and MS/MS spectrum are used to identify metabolites.
Example data of profiling and estimation of structure using frozen liver cells are shown below.

Example data of profiling using hepatocyte
Example data of profiling using hepatocyte
Example data of estimation of structure
Example data of estimation of structure

Menu of compounds ready to analyze

We have a menu of compounds analyzed by LC-MS/MS which includes agonist/substrate of drug interactions in human plasma/urine or existing drugs in human plasma.

Agonist/substrate of drug interactions in human plasma/urine

CYP Analyte Matrix Anti-coagulant Quantification range Stability
(Storage condition)
CYP1A2 Caffeine Human plasma Sodium heparin 25-12500 ng/mL -20℃/-80℃,
for 12 months
CYP2D6 Metoprolol Human plasma Sodium heparin 1-500 ng/mL -20℃/-80℃,
for 12 months
CYP2C19 Omeprazole Human plasma Sodium heparin 1-500 ng/mL -20℃/-80℃,
for 12 months
CYP3A Midazolam Human plasma Sodium heparin 0.1-50 ng/mL -20℃/-80℃,
for 12 months
CYP2B6 Bupropion Human plasma Sodium heparin 1-500 ng/mL -20℃ for 3 months,
-80℃ for 12 months
CYP2C8 Repaglinide Human plasma Sodium heparin 0.1-50 ng/mL -20℃/-80℃,
for 12 months
CYP2C9 R-Warfarin Human plasma Sodium heparin 1-500 ng/mL -20℃/-80℃, for 12 months
CYP2C9 S-Warfarin Human plasma Sodium heparin 1-500 ng/mL -20℃/-80℃, for 12 months
Transporter Analyte Matrix Anti-coagulant Quantification range Stability
(Storage condition)
MATE1, MATE-2K, OCT2 Metformin Human plasma EDTA-3K 5-2500 ng/mL -20℃/-80℃,
for 3 months
MATE1, MATE-2K, OCT2 Metformin Human urine _ 2-1000 μg/mL -20℃/-80℃,
for 3 months

Existing drugs in human plasma

Analyte Matrix Anti-coagulant Quantification range Stability
(Storage condition)
Donepezil Human plasma Sodium heparin 1-500 ng/mL -20℃/-80℃,
for 12 months
Memantine Human plasma Sodium heparin 2-1000 ng/mL -20℃/-80℃,
for 12 months
Rivastigmine Human plasma Sodium heparin 0.5-20 ng/mL -20℃ for 4 months,
-80℃ for 12 months
Rabeprozole Human plasma Sodium heparin 0.5-500 ng/mL -20℃/-80℃,
for 6 months
Galantamine Human plasma Sodium heparin 1-500 ng/mL -20℃/-80℃,
for 12 months
Paroxetine Human plasma Sodium heparin 0.5-200 ng/mL -20℃/-80℃,
for 12 months
Moxifloxacin Human plasma Sodium heparin 0.05-20 μg/mL -20℃/-80℃,
for 12 months