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Home / Equine Research Bank / BMC Vet Res / Pharmacokinetic analysis of topical tobramycin in equine tea...
BMC veterinary research2012; 8; 141; doi: 10.1186/1746-6148-8-141

Pharmacokinetic analysis of topical tobramycin in equine tears by automated immunoassay.

Abstract: Ophthalmic antibiotic therapy in large animals is often used empirically because of the lack of pharmacokinetics studies. The purpose of the study was to determine the pharmacokinetics of topical tobramycin 0.3% ophthalmic solution in the tears of normal horses using an automated immunoassay analysis. Results: The mean tobramycin concentrations in the tears at 5, 10, 15, 30 minutes and 1, 2, 4, 6 hours after administration were 759 (±414), 489 (±237), 346 (±227), 147 (±264), 27.6 (±28.4), 14.8 (±66.6), 6.7 (±18.6), and 23.4 (±73.4) mg/L. Mean tobramycin concentration was maintained above the MIC90 for commonly isolated bacteria for 68.5 min. Conclusions: A single dose of topical tobramycin resulted in therapeutic concentrations of tobramycin in the tears for 1 h after administration. Therapeutic levels of tobramycin remained in equine tears 6 times longer than was reported in rabbit tears.
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Publication Date: 2012-08-21 PubMed ID: 22909398PubMed Central: PMC3489562DOI: 10.1186/1746-6148-8-141Google Scholar: Lookup
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  • Clinical Trial
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research evaluated the effectiveness of a topical antibiotic, tobramycin, in treating eye conditions in horses. It was found that a single dose of tobramycin can maintain therapeutic levels in horses’ tears for around 1 hour, which is six times longer than in rabbits.

Objective of the Research

  • The aim of the research was to understand the effectiveness, absorption, and distribution of the topical antibiotic tobramycin in the tears of horses. This was carried out to provide more scientific backing to the common empirical use of antibiotics for ophthalmic therapy in large animals.

Methodology

  • An automated immunoassay analysis was used to examine the pharmacokinetics of a 0.3% tobramycin ophthalmic solution. This method of analysis uses a biological molecule in a horse’s body to indirectly measure the concentration of the tobramycin antibiotic in its tears.
  • The concentration of tobramycin was measured at specified intervals (5, 10, 15, 30 minutes and 1, 2, 4, 6 hours) after the administration of the antibiotic.

Findings

  • The results reflected different tobramycin concentrations in the tears at the respective time intervals. The highest concentration was observed 5 minutes post administration, and it gradually decreased over time.
  • Moreover, the tobramycin concentration in the tears was maintained above the Minimum Inhibitory Concentration (MIC90; the minimum concentration that inhibits the growth of 90% of organisms) for the bacteria commonly responsible for eye infections for approximately 68.5 minutes.

Conclusions

  • A single dose of topical tobramycin was found to be capable of maintaining therapeutic concentrations in equine tears for approximately 1 hour after administration. This suggests that the medicine can effectively inhibit bacterial growth and facilitate healing during this period.
  • Notably, tobramycin remained in equine tears six times longer than was reported in previous studies using rabbit tears. This implies that therapeutic tobramycin effects could last significantly longer in horses than in smaller animals like rabbits, showcasing its potential effectiveness when used for equine ophthalmic therapy.

Cite This Article

APA
Czerwinski SL, Lyon AW, Skorobohach B, Léguillette R. (2012). Pharmacokinetic analysis of topical tobramycin in equine tears by automated immunoassay. BMC Vet Res, 8, 141. https://doi.org/10.1186/1746-6148-8-141

Publication

BMC veterinary research
ISSN: 1746-6148
NlmUniqueID: 101249759
Country: England
Language: English
Volume: 8
Pages: 141

Researcher Affiliations

Czerwinski, Sarah L
  • Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
Lyon, Andrew W
    Skorobohach, Brian
      Léguillette, Renaud

        MeSH Terms

        • Administration, Topical
        • Animals
        • Anti-Bacterial Agents / administration & dosage
        • Anti-Bacterial Agents / chemistry
        • Anti-Bacterial Agents / pharmacokinetics
        • Automation
        • Female
        • Horses
        • Immunoassay / methods
        • Immunoassay / veterinary
        • Male
        • Reproducibility of Results
        • Tears / chemistry
        • Tobramycin / administration & dosage
        • Tobramycin / chemistry
        • Tobramycin / pharmacokinetics

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        Citations

        This article has been cited 1 times.
        1. Ibrahim A, Abd-Elrasoul MAA, Sabra MS. Impact of pH modification of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus). BMC Vet Res 2024 May 23;20(1):218.
          doi: 10.1186/s12917-024-04072-1pubmed: 38778405google scholar: lookup
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