In Vitro & In Vivo Assays

invivo|invitro|testing|parasites

In Vitro & In Vivo Assays

In Vitro Assays

Helping you develop and maintain effective drugs

In vitro assays are used when the particular stage of a target organism (usually a parasite or bacteria) can exist long enough outside a host to allow an assessment of its susceptibility to treatment. They are also used when a free-living stage is significant enough to merit assay.

We use in vitro assays to:

  • Compare the effectiveness of a candidate compound with an existing compound
  • Identify the level at which a candidate compound is effective

Although the results cannot be directly extrapolated into the final host animal, in vitro assays are a useful and cost-effective way to carry out early screening of candidate compounds.

Efficacy

We can use an in vitro assay, or series of assays, to determine the level of treatment required to kill a particular parasite. We evaluate different concentrations of the treatment to establish the optimum dose.

Resistance

When a parasite develops resistance to a treatment the dose response curve moves along the X-axis. We use in vitro assays to confirm the presence of and characterise this movement.

In Vivo Assays

Helping you develop and maintain effective drugs

In vivo assays are used to conduct preclinical and clinical evaluations of candidate compounds and their formulations. They are carried out in or on the target host animal.

We use in vivo assays on target compounds and formulations to:

  • Test their efficacy
  • Assess their safety
  • Establish and confirm the best dosage

You can use the results of the studies to support your submission to government regulators when your product is ready to be considered for registration and authorisation.

Efficacy

We can assess the efficacy of a treatment on animals that are carrying natural infection. We administer the treatment and then compare, for example, the WECs of treated and untreated animals. To test how well a treatment works as a preventative therapy, we can administer it first and then challenge the animals with the parasite. We can also collect adult worms from the animal in order to assess a treatment’s efficacy.

Resistance

We can test specific species of parasite to see if they’re developing resistance to a particular treatment. We administer the treatment to animals carrying the parasite and, after sufficient time for the treatment to have its full effect, examine the number and stages of any parasites that remain. We then compare this result to that expected when the treatment is administered to susceptible parasites.

Ectoparasites and Endoparasites

Ectoparasites live, feed and breed on the outside of animals.

Endoparasites  live, feed and breed on the inside of animals; some species of parasites require a intermediate host to complete their life cycle.

How our in vitro assays help you combat them

In vitro assays help you determine the efficacy of your candidate compound and identify the level at which it is effective. They can also confirm that a parasite is developing resistance to a particular compound.

The tests can simultaneously evaluate the same dose rate or exposure level and different dose rates or exposure levels.

We can carry out in vitro assays on many ectoparasites such as ticks, fleas, lice, mites and various stages of biting or blow flies.

We can carry out in vitro assays on many endoparasites including fluke and nematodes.

How our in vivo assays help you combat them

In vivo assays help you determine the efficacy and safety of your candidate compound and identify the level at which it is effective. They can also help confirm whether or not a parasite is developing resistance to a particular compound.

We run in vivo assays on animals that are carrying a natural infestation of many endoparasites including fluke and nematodes.

We run in vivo assays on animals that are carrying a natural infestation of ectoparasites such as:

  • Ticks
  • Lice
  • Mites
  • Various stages of biting or blow flies

We can also apply the treatment and then introduce the parasite to test whether the treatment will prevent an infestation.

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mite|parasite
Ridgeway Research Linognathus crop copy
ixodes|tick