GLP 14 Day Repeat Dosing Toxicology in Rats

This GLP study design is used to determine the toxicity of a test article in male and female rats after repeat dosing for 14 days followed by a 7 day recovery period

Catalog number EA609

Required from Customer

  • Test article in a form appropriate for dosing; see Note 1
  • Instructions for dosing vehicle preparation
  • Dose, dose route, and test article stability information
  • Test article Certificate of Analysis (COA)
  • Master Study Protocol (MSP) and Bioanalytical Study Plan (BSP) must be written and approved prior to study initiation


  • Toxicology report
  • No-adverse event limit (NOAEL)
  • In-life observation: mortality, morbidity, clinical signs, and body weight
  • Clinical pathology, clinical chemistry, and necropsy results
  • If optional toxicokinetics (TK) analysis is included:
  • Table of measured concentration of test article in each sample
  • Table of TK parameters (AUC, Cmax, and Tmax) for each dose route
  • Half-life (t1/2), clearance and volume of distribution after IV adminstration
  • Bioanalytical method and validation data
  • Raw analytical data
  • Representative chromatograms and calibration curves


  • Test article in an appropriate dosing vehicle

Study System

  • Conscious, male and female Sprague-Dawley rats weighing between 200 and 400 grams following ≥7 days of pre-study acclimation. Water is available ad libitum.

Study Conditions

  • Administer test article in parallel to groups of rats (total of 136 animals) according to the design in the Table on page 2
  • Each treatment by single oral gavage , IV, SC, or IP dose
  • Treat each group once daily for 14 days
  • Allow recover animals to recover for 7 days
  • In-life observations and terminal investigations; see Note 2
  • Optional TK (satellite TK animals only); see Note 6

Study QC and QA

  • 5/8 of the calibration standards must be within ±15% of the theoretical values (±20% at the LLOQ)
  • Two-thirds of the batch QCs must be accurate to within of nominal, and at least one QC must pass at each level in order to accept the run
  • Incurred sample re-analysis will be performed to confirm bioanalytical assay reproducibility
  • QA Unit performs in-study and post-study audits


  1. Test article requirements for development and validation of the bioanalytical method (in addition to the amount needed for the in vivo study):
    1. Small molecule: ~70 mg of test article in powder form and ~30 mg of deuterated internal standard in powder form for bioanalysis
    2. Biologic or other test article: Amount TBD
  2. If required, Absorption Systems can determine a suitable dosing vehicle, at an additional charge, and prepare it for the study. Alternatively, Absorption Systems can prepare the dosing vehicle according to instructions provided by the Customer.
  3. In-life observations and terminal investigations
    1. Mortality and morbity: twice daily
    2. Clinical signs: daily and 1 hour post-dose on Day 1
    3. Body weight: weekly (including pre-dose) and at termination
    4. Clinical pathology: hematology, coagulation and clinical chemistry at termination on all main and recovery animals
    5. Necropsy: Full gross necropsy with macroscopic examination on all animals and preservation of a full tissue list
    6. Organ weights: All organ weights from animals examined at necropsy
    7. Histopathology: All tissues from high dose and control groups for main study animals and recovery animals will be brought to slide, H&E stained, and examined by a board-certified pathologist. If abnormalities are seen, the next lower dose group will be examined for pathology, a process that will continue until no abnormalities are seen or all groups have been examined. Price does not include histopathology for additional groups (after high dose and control).
  4. The standard anticoagulant is sodium heparin. The customer can specify that another anticoagulant be used.
  5. The test article must be a small molecule for Absorption Systems to perform plasma sample analysis. Otherwise, plasma samples will be shipped to the Customer for analysis.
  6. Optional TK includes:
    1. Sampling at 6 time points each (up to 24 hours post-dosing) on Day 1 and Day 14
    2. Prepare plasma from blood samples and store at -70°C prior to analysis
    3. Terminate TK animals without further investigation after last bleed
    4. Determine the concentrations of test article in dosing solution and incurred samples using a generic LC/MS/MS method with a minimum 5 point calibration curve
    5. Use non-compartmental analysis to determine TK parameters
Main Study
Recovery TK (optional)
Female   Male
Female   Male
1 Vehicle 10 10 5 5 0 0
2 Low Dose 10 10 0 0 6 6
3 Mid Dose 10 10 0 0 6 6
4 High Dose 10 10 5 5 6 6



  1. The customer must specify:
    • the dose route—oral, IV, SC, or IPthe doses (mg/kg)
    • the formulation instructions, if applicable
    • the sampling time points for TK, if conducted
    • which organs to be collected or weighed after termination
  2. The customer can request:
    • collection and bioanalysis of plasma samples for TK analysis
    • that Absorption Systems determine a suitable dosing vehicle
    • that Absorption Systems prepare the dosing vehicle
    • an anticoagulant other than sodium heparin
    • histopathology on selected organs