PK PD Pharmacokinetics | Mechanism of Toxicology | MTD NOAEL | Cancer model

Drik determines the Median Lethal Dose/Maximum Tolerated Dose (MTD) and No Observable Adverse Effect Level (NOAEL) in toxicity studies. PK/PD Pharmacokinetic modeling enable selection of appropriate dose levels. Cancer model available include cell lines of interest, xenograft, orthotopic and PDX studies. Drugs marketed should be safe and be effective to patients. Evaluating mechanism of drug action or drug metabolites resulting in toxicity can be evaluated. Drug discovery includes many studies to define proof of concept. But most important step includes pre-clinical research and clinical trials.
The following in vivo studies are currently offered in rodents/dogs (non-GLP; GLP: collaborators) including PK/TK studies. We make use of our partner sites for GLP studies.


Acute Study:

  • To determine the Median Lethal Dose/Maximum Tolerated Dose (MTD) and No Observable Effect Level (NOEL)
  • Identify potential target organs for toxicity, determine reversibility of toxicity, and identify parameters for clinical monitoring
  • Duration of Study: A few days to 2 weeks after a single dose
  • Route of administration: Multiple routes possible, depending on the need and requirement
  • End points: Mortality, Clinical pathology, Gross necropsy, Weight change, Signs of toxicity

Sub-acute Study:

  • To determine toxicity after repeated administration of the test compound
  • Establish doses for sub-chronic studies
  • Duration of Study: 14 days
  • Route of administration: Given by the same routes as previous toxicity tests
  • End points: Mortality, Signs of toxicity, Pathology and histopathology, Weight change, Clinical pathology

Sub-chronic Study:

  • To establish a “no observable effect level” (NOEL) and characterize dose-response relationships following repeated doses.
  • To identify and characterize specific organs affected after repeated administration
  • Select appropriate dose for chronic exposure studies
  • Duration of Study: Rodent and a higher species- 14d to 6-12m
  • Route of administration: Same routes as previous toxicity tests, the lowest dose producing no apparent toxicity and the highest dose producing not more than 10% mortality
  • End points: Mortality, Clinical pathology, Gross necropsy, Weight change, Signs of toxicity


Pre-clinical Liver Injury Markers:

The most common traditional biomarkers of drug-induced liver injury (DILI) are alanine aminotransferase (ALT) and aspartate aminotransferase (AST). They are preliminary biomarkers, but they have several limitations. During drug development process, transaminase increases are commonly observed in the absence of evidence of injury to tissue, and, on the other hand, sometimes do not increase even when liver tissue injury is observed. The following markers recommended by Predictive Safety Testing Consortium are offered by us

  • First set: ALT, AST, GLDH, MDH, PNP
  • Second set: ARG-1, GST-alpha
  • Third set: miR-122

Clinical Liver Injury Markers:

DILI is one of the most common adverse events and can sometimes result in liver failure in human. DILI can lead to restrictions on use, black box warnings following severe reactions, and the prelaunch and post market attrition of pharmaceuticals. Therefore, we have focused specifically on biomarkers that would predict early in the course of therapeutic treatment. These biomarkers will help pharmaceutical industry whether a patient might progress to serious liver injury or adapt, and thus safely continue with possible therapeutic treatment.

  • First set: GLDH, MDH, GST-alpha, ARG-1, miR122
  • Serum enzymes to monitor liver injury: ALP, 5’-NT, GGT, LDH, Creatine phosphokinase, cholinesterase


Most drugs found to cause nephrotoxicity exert toxic effects by one or more common pathogenic mechanisms. These include altered intraglomerular hemodynamics, tubular cell toxicity, inflammation, crystal nephropathy, rhabdomyolysis, and thrombotic microan-giopathy. Several possible drug-induced kidney biomarkers are under investigation.

First set: KIM-1, urinary IL-18, TFF3, urinary NAG, urinary GST-alpha, urinary NGAL

Pre-clinical Kidney: Phase I

European Medicines Agency (EMA), US Food and Drug Administration (FDA), and Pharmaceuticals and Medical Devices Agency (PMDA) Japan issued following test, can be utilized on a voluntary basis.

  • First set: urinary beta2-microblobulin, urinary KIM-1, TFF-3

  • Second Set: Rat toxicology studies to monitor drug-induced kidney injury.

  • Third set: Serum cystatin c, RBP-4, GST-alpha, NAG, NGAL


Mouse models of cancer have consistently been used to determine the in vivo activity of new anti-cancer therapeutics prior to clinical development and testing in humans. The most widely used one is the human tumor xenograft model. In this model, human tumor cells (patient derived tumors (PDX) or tumor cell lines) are transplanted, either under the skin (xenograft) or directly into the organ (orthotopic) in which the tumor originated or associated, into immunocompromised (nude or SCID) mice that do not reject human cells. The resultant tumor and the response to appropriate therapeutic regimes can be studied in vivo. DRIK utilizes commercially available tumor cell lines or cell lines provided by our customer. Assessment of tumor growth and size can be visualized via bioluminescence imaging (BLI). Based on our customer requirements, DRIK can perform the studies at your earliest. The study process is not limited to, cell culturing & cell implantation, animal weight measurement, determination of tumor size, blood sampling, organ sampling, paraffin embedding of tumors or organs and histopathology.

Cardiac toxicity:

Cardiotoxicity is becoming one of the most important complications of drug development and their treatments. Cardiac toxicity represents a new development or a worsening of arrhythmias in patients with or without clinical symptoms. The following markers recommended by Predictive Safety Testing Consortium can be assayed in addition to traditional toxicity markers:
Natriuretic Peptides (NPs), LDH, CK isozymes, AST, SGOT, myoglobin, myosin, cardiolipin, Troponins (TIC)


hERG Screening in Guinea Pigs:

The human Ether-à-go-go Related Gene (hERG) is important in coordinating ECG QT interval in the mammalian heart. hERG screening has a important role in screening potential cardiotoxic compounds in the early phase of drug discovery. The QT interval is the period where the heart ventricles are prompted to contract and then build the potential to contract again. When the hERG channel is blocked or prolongation of the QT interval happens, it can lead to torsade de pointes, a life-threatening ventricular arrhythmia. This condition may happen either by genetic mutation or through drug interaction by delaying the repolarization of the ventricles. Many drugs have the potential to block the hERG channel, and the FDA has recommended all new pharmaceuticals to be screened prior to clinical trials.

To help customers in their drug discovery efforts we offer screening in guinea pig which is advantageous for the following reasons:

  • Low compound requirement
  • Can avoid costly telemetry studies during early development stages
  • Please contact us for more information regarding our services.

Quality and accuracy of early in vitro and in vivo studies occupy an essential role in drug discovery and development processes. While the primary goal of ADME (absorption, distribution, metabolism and excretion) study is to discover high-affinity ligands against the target, monitoring of drug-like properties is also accomplished. The foremost reasons for the failure of many new drug candidates are poor Pharmacokinetic (PK), ADME and Toxicological characteristics. The above factors alone account for up to 50% of the attrition rate of new drug candidates during the drug development process. The high cost of R&D and fast pace with which modern medicinal chemists can synthesize new compounds places a high demand on early ADME/PK groups.

To optimize the pharmacokinetic characteristics of a drug candidate ADME studies are performed. It helps in identification of the metabolic pathways and provides valuable input for the design of in vivo studies. We offer cost-efficient standardized and customized assays as per the client’s requirement for ADME parameters. ADME capabilities of DRIK include the following:

Physicochemical Studies:

• Partition coefficient (LogD/LogP)
• Solubility (UV/Visible spectroscopy)
• Chemical stability at different pH
• Biological matrix stability (serum/plasma/blood/microsomal/hepatocytes/tissue homogenates /simulating fluids)

Absorption/Distribution Assays:

• PAMPA (parallel artificial membrane permeability assay)
• Caco-2 permeability study
• Tissue permeability studies – Franz Diffusion Assay


• CYP inhibition/Induction (CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4)
• Drug–Drug Interaction (DDI) studies
• Pathway determination (Phase I and Phase II)
• Half-life/clearance determination using Microsomes / Hepatocytes / S9 fractions / CYP across species (Human/Rat/Mouse/Dog)
• Metabolite identification with Microsomes/Hepatocytes and S9 fraction across species (Rat/Mouse/Dog/Human)
CYP Inhibitor: Furafylline, Pilocarpine, Quercetin, Fluconazole, Ticlopidine,
CYP Inducer: Omeprazole, Rifampicin, Phenytoin, Quinidine, Ketoconazole


We have the capabilities to undertake medium to high throughput Bio-analysis and method development through our partners.

  • • Pharmacokinetic Studies
  • • LLNA – Local Lymph Node Assay
  • • E-LLNA – Enhanced LLNA
  • • MEST – Mouse Ear Swelling Test
  • • Custom In Vivo Studies
  • Acute:

  • • Acute Oral Toxicity
  • • Acute Dermal Irritation / Corrosively
  • • Acute Irritation / Corrosively
  • Sub-Acute:

  • • 7/14 days Dose Range finding Study
  • • 14/28 Days Repeated Dose Toxicity Studies
  • Subchronic & Chronic:

  • • 28/90/180 days Dose Range Toxicity Studies
  • • Chronic Toxicity / Carcinogenicity
  • • Neuro Toxicity Studies
  • • 14/28 Days Repeated Dose Toxicity Studies

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