Turner Scientific's preclinical contract research services help advance our clients' compounds and devices toward IND/IDE approval and clinical trials by evaluating efficacy, and detecting and defining ototoxicity.

We are pleased to be partnered with Sinclair Research, a leading multi-specialty biomedical research services company. Turner Scientific will provide GLP preclinical otic research at Sinclair’s state of the art facility in Auxvasse, MO. We will continue to provide non-GLP otic research in our facility in Jacksonville, IL. For more information on our partnership with Sinclair Research, click here.

Approximately one-third of all FDA approved drugs enter the cochlea and vestibular organs.

-Sider 4.1

Turner Scientific is a leader in preclinical auditory efficacy and ototoxicity contract research services.

We serve a wide variety of biotechnology companies, pharmaceutical sponsors, and general contract research organization (CRO) clients by assessing the efficacy of new hearing/tinnitus treatments, and the potential for ototoxicity, hearing loss, tinnitus, and balance/vestibular disorders of any medication.

Guided by a comprehensive scientific background, Turner Scientific provides a broad array of behavioral audiogram, electrophysiological (ABR), and histological studies to assess ototoxicity, hearing and tinnitus. Multiple drug administration pathways and noise exposure models are available.

As a niche expert partner, Turner Scientific provides unmatched study design and execution, data analysis, specialty report writing, and sponsor communication by hearing research experts.

Ototoxicity is a significant concern for the broader toxicology space.


Hearing and balance assessments should not just be of interest to hearing scientists developing treatments for hearing disorders.


The ear is an untapped resource for drug development, toxicity screening, safety and reproductive toxicology work. Turner Scientific clients are able to more efficiently develop their pipeline compounds by evaluating the effects on the ears in early developmental stages. This allows for an estimation of general toxicity, while helping to avoid the side effects of hearing loss, imbalance, and tinnitus that are already common among FDA approved drugs.

Predictor of General Toxicity

Ototoxicity assessment is critical for safe and efficient drug development. Acting like a "canary in a coalmine", the auditory and vestibular systems present an under-exploited sentinel prognosticator of general drug toxicity:

  • Hair cells (the receptors for hearing and balance) are especially sensitive to toxins

  • Hundreds of drugs, chemicals, and medical conditions are toxic to hair cells

  • Hair cells are not capable of regenerating in humans

  • The auditory nerve and central brain auditory structures are also sensitive to toxins

Ototoxicity assessment is crucial to drug development given the widespread prevalence of hearing loss.

  • The World Health Organization estimates that hearing loss affects more than 5% of the world's population (360 million people, including 32 million children).

  • Tinnitus (ringing in the ear) occurs in 25% of Americans every year with 8% experiencing tinnitus daily (Turner J et al, J Neurosci Res. 2012 July ; 90(7): 1480–1488).


Turner scientific can not only assesses the potential for any drug or chemical to cause hearing loss and tinnitus, but we also test the ability of certain therapeutic compounds to improve hearing and tinnitus.

Predictor of General Toxicity

Turner Scientific is driven to reduce damage to the auditory and vestibular organs, and to reduce the impairment to quality of life that accompanies these complications. Ototoxicity is common to many medications, chemicals, and medical conditions:


• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as aspirin, Ibuprofen

• Aminoglycoside antibiotics such as kanamycin, neomycin, gentamycin

• Additional antibiotics such as erythromycin, vancomycin, and many others

• Diuretics such as furosemide, bumetanide

• Chemotherapeutic (cancer) agents such as bleomycine, cisplatin, carboplatinum, methotrexate

• Antimalarials such as chloroquine

• Cardiac medications such as propanolol, quinidine

• Anesthetics such as lidocaine, bupivacain

• Psychopharmacologic agents such as amitryptiline, benzodiazepines, bupropion, fluoxetine, imipramine, lithium

• Glucocorticoids such as prednisolone, ACTH

• Thalidomide

To learn more about Turner Scientific CRO capabilities, visit the following links, or contact us directly.

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