In vivo pharmacokinetics

 

Our pharmacokinetics services

We provide end-to-end pharmacokinetics studies including validation of bioanalytical methods, vehicle finding and stability testing, in-life part in rodent and non-rodent species, plasma/serum analysis, urine and faeces collection in metabolic cages, tissue homogenate analysis, quantitative bioanalytics (DMPK) and bioavailability in addition to the pharmacokinetics calculations.

Animal species

We routinely provide pharmacokinetics studies in mouse, rat, hamster, guinea pig, rabbit and dogs and help you in choosing the correct species for the pharmacokinetics studies.

Administration routes and formulations

Available dose routes include:

  • intravenous (also jugular vein catheter)(IV)
  • oral (PO)
  • subcutaneous (SC)
  • intradermal (ID)
  • intraperitoneal (IP)
  • intramuscular (IM)
  • sub lingual (SL)
  • nasal (spray, droplets)

Formulation for IV dosing:

  • Vehicle finding
  • Vehicle stability

Matrices

We collect different matrices, including plasma/serum/whole blood, and solid tissues (liver, lungs, brain, heart, muscle, testis etc.). Bioanalysis is possible from all of these matrices. In oncology studies, the matrix can also be the tumor tissue.

We also routinely collect urine and feces by conducting the studies in metabolic cages with an ability to immediately chill the released excrements (rat).

Bioanalytical services

We provide you with a flexible solution with the possibility to order bioanalytical services and pharmacokinetic calculations, or your project can be limited to study design, dosing and sample collection only.

Bioanalytical services:

  • Bioanalytical method validation
  • Quantitative bioanalysis (matrices: plasma, serum, urine, tissue homogenate)
  • Metabolite identification and profiling
  • Pharmacokinetic calculations
  • Pharmacokinetic parameters AUC, t1/2, Cl, V, Tmax, Cmax, Bioavailability (F) (WinNonLin)

Our pharmacokinetics study packages

We provide both fast, fixed-price and ready solutions for pharmacokinetics studies as well as studies tailored on customer’s request. These are fixed price study packages with very fast delivery times, but also allowing tailoring of study parameters.

RatPilot, MousePilot

Simple animal-saving determination of determination of Cmax, AUC and T1⁄2 of a compound including identification of biotransformations and elucidation tentative metabolite structures.

  • Animal model: SD / NMRI
  • One route: i.v. or p.o.
  • Single dose
  • 3 sample / time point
  • n= 3 (rat) / 18 (mouse)
  • Blood collection at time points
  • i.v.: 5, 15, 30, 60 min, 2, and 6 h
  • p.o.: 30, 60 min, 2, 4, 6, and 8 h
  • Number of samples = 18 / dose route

RatDMPK, MouseDMPK

Comprehensive but animal-saving determination of oral bioavailability, pharmacokinetics and metabolism of a compound in the rat or mouse.

  • Animal model: SD / NMRI
  • 2 routes: i.v. and p.o.
  • Single dose
  • 3 sample / time point
  • n= 6 (rat) / 36 (mouse)
  • Blood collection at time points
  • i.v.: 5, 15, 30, 60 min, 2 and 6h
  • p.o.: 30, 60 min, 2, 4, 6 and 8 h
  • Number of samples = 36 / test item

DogDMPK

Comprehensive determination of oral bioavailability, pharmacokinetics and metabolism of a compound in the dog.

  • Animal model: Beagle
  • 2 routes: i.v. and p.o.
  • Single dose
  • As a cross-over study
  • Washout period: at least 7 days
  • 3 sample / time point
  • n= 3 dogs
  • Blood collection at time points
  • i.v.: 5, 15, 30, 60 min, 2 and 6 h
  • p.o.: 30, 60 min, 2, 4, 6 and 8 h
  • Number of samples = 36 / test item

CassettePilot

A cassette-dosing (cocktail/N-in‐one dosing) study package to rank a number of compounds in the same series according to their tentative oral bioavailability and systemic clearance in an animal’s body in a cost-efficient manner. The simultaneous dosing of several compounds at the same time leads to much reduced animal usage and lower number of samples for analytics, leading therefore to a clearly faster overall turnaround time and reduced costs. Consumption of study compounds is lower (lower concentrations are used) in comparison to the traditional approach by with individual dosing, and an additional advantage of decreased inter-individual variability in comparison of compounds is obtained.

In cassette dosing, a single bolus dose is given either i.v. or p.o. route. Both groups contain two animals. Formulation typically contains 2‐5 compounds at the same time plus possible reference compounds with known pharmacokinetics profile. Plasma samples are collected at five time points after dosing. Samples are analysed by a single UPLC-MS/MS run each. These studies are typically done in mice and rats.

  • 2 routes: i.v. and p.o.
  • Single dose
  • 3 sample/ time point
  • n= 2 mice/rats
  • Blood collection at time points
  • i.v.: 15, 30, 60 min, 2 and 6 h
  • p.o.: 30, 60 min, 2, 4, 6 h
  • Number of samples = 20 / test item cocktail

The LC/MS/MS method used is not generic, but is optimized in each case using the study compounds to provide the best chromatographic retention, peak shape, mass spectrometric ionisation conditions and MS/MS detection reaction (MRM). Pharmacokinetic parameters are solved with standard non-‐compartmental analysis using WinNonLin software.

Note that the cassette-dosing approach is not intended for elucidation of accurate PK parameters of each compound, but rather for screening type rank‐ordering of the compounds.

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Contact us for more information or tailored studies

Background

Quantitative measurements of pharmacokinetics (PK) provide valuable information on the bioavailability of your compound and they are essential for the design of preclinical pharmacological and toxicological studies. We support you in the lead optimization with in vivo pharmacokinetics and biodistribution services.

Typically the first pharmacokinetics studies are conducted in small rodents (mice or rat, often depending ont he amount of the test item available) and the aim is to find out the bioavailability and plasma clearance. This is done by dosing the test item both by oral (PO) and intravenous (IV) routes, followed by plasma sampling at given intervals (for example  at 5, 15, 30, 60 min, 2 and 6 hrs for IV dosing and 30, 60 min, 2, 4, 6, and 8 hrs for PO dosing). A LC-MS/MS bioanalytics method is developed for the test compound and the concentration of the compound at the different interval samples is quantitated. Based on this data, different pharmacokinetics parameters are calculated, like terminal halflife (t1/2 ), maximum plasma concentration (Cmax) and sampling time of Cmax (tmax), area under the concentration-time curve from dosing time to infinity (AUC),  area under the concentration-time curve from dosing time to tlast (AUC0-tlast),  and absolute bioavailability (F). Depending on the intended route of administration, PO route may be also replaced with other dosing route, like subcutaneous (SC), intradermal (ID), intramuscular (IM), intraperitoneal (IP),  sublingual (SL) or nasal dosing. Benefits of the other dosing routes include slowed release of the test compound (like in IM route) and avoiding the first-pass metabolism (happens with PO dosed compounds). Some of the dosing routes are limited by the dosing volume (like low volumes can be adjusted only for IM and ID routes).

Sometimes, when studying a larger number of compounds in the first pharmacokinetics studies, cassette-dosing (also called as N-in-one dosing or cocktail dosing) is used, in which the different compounds from the same synthesis series are administered to the same animal at same time, however, this strategy will only give very preliminary data due to potential accumulating metabolism and drug interaction phenomena with the increasing number of administered compounds. Typically to alleviate the possible drug interaction and altered metabolism issues, smaller amounts of compounds are used and also reference compound(s) with a known pharmacokinetics profile are included in the dosing cocktail.

Vehicle to which the test compound is dissolved for dosing is one important parameter in pharmacokinetics studies. Typically especially with IV dosing, the vehicle must be aqueous enough suitable for IV injection whilst still being able to solubilize the compound. Poorly chosen vehicle can ruin the pharmacokinetics studies, either as destabilizing the compound itself or causing the compound to precipitate and not entering to the systemic circulation. Incomplete solubility of the compound to the chosen vehicle is often less of a problem with PO dosing route, however, the different environments in gastric tract may cause stability issues for the compound (like different pH values in GI tract).

Following these initial pharmacokinetics studies, in followup studies also the compounds tissue distribution and excretion is evaluated. The in-life part will take place in special metabolic cages, allowing collection of urine and faeces and with the last time point, tissues like liver, lungs, heart, brains, kidney and testis are collected. Criteria for the selection of the species for the followup PK studies can include the cross-species in vitro metabolism data obtained before PK study as well as the species used to generate in vivo efficacy data.