| Size | Price | Stock | Qty |
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| 5mg |
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| Other Sizes |
| Targets |
As an isotope-labeled compound, Tilmicosin-d3 does not have a biological target but is used to track the unlabeled drug. The primary target of unlabeled Tilmicosin is the 50S subunit of the bacterial ribosome. As a macrolide antibiotic, it binds to this site and inhibits bacterial protein synthesis. It acts as a calcium channel antagonist, which may contribute to its effects. The antibacterial spectrum includes activity against macrolide-susceptible strains of Mannheimia haemolytica and Pasteurella multocida, two major bacterial pathogens causing respiratory disease in cattle and sheep. Tilmicosin-d3 is used as an analytical standard to study these interactions.
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| ln Vitro |
Drug compounds have included stable heavy isotopes of carbon, hydrogen, and other elements, mostly as tracers for quantification throughout the drug development process. Due to its potential to alter the pharmacokinetic and metabolic characteristics of medications, deuteration has drawn attention[1].
In vitro activity is attributed to the parent compound, tilmicosin. It is active against macrolide-susceptible strains of M. haemolytica and P. multocida with minimum inhibitory concentrations (MICs) of 4 and 4 microM, respectively. It is also active against a hyperpermeable strain of E. coli (MIC = 2 microM) and a wild-type E. coli strain (MIC = 128 microM). Furthermore, it inhibits bacterial protein synthesis with an IC50 value of 0.36 microM [40L15-L19]. The labeled version is used as an internal standard to quantify the unlabeled drug in these in vitro activity assays. |
| ln Vivo |
In vivo activity and toxicity have been characterized for unlabeled tilmicosin. It is an orally active antibiotic and is used in veterinary medicine for the treatment of respiratory diseases in cattle and sheep, primarily those caused by Mannheimia and Pasteurella species. However, the compound has known in vivo toxicity. For example, in mice, tilmicosin (75 mg/kg) increases serum levels of creatine kinase (CK) and the MB isoform of CK (CK-MB), as well as malondialdehyde (MDA), which are markers of cardiotoxicity and oxidative stress [40L20-L22].
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| Enzyme Assay |
Binding assays for tilmicosin typically involve ribosome binding studies. A cell-free assay can be performed using bacterial ribosomes isolated from E. coli. The ribosomes are incubated with a fixed concentration of a radiolabeled macrolide (e.g., [3H]-erythromycin) and increasing concentrations of unlabeled tilmicosin. After incubation, the ribosomes are collected by filtration through nitrocellulose filters, and the amount of bound radiolabel is measured by liquid scintillation counting. The ability of tilmicosin to displace the radiolabeled ligand is used to calculate its binding affinity for the 50S ribosomal subunit.
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| Cell Assay |
Since tilmicosin-d3 is an analytical standard, not a therapeutic agent, it is not used in cell-based assays as a treatment. Instead, it is used as a tool for sample preparation and analysis in assays investigating the effects of the parent compound, tilmicosin. A typical protocol would involve treating bacterial cell cultures (e.g., M. haemolytica) with unlabeled tilmicosin. Then, during the sample preparation for analysis (e.g., for mass spectrometry), a known amount of Tilmicosin-d3 is added. The internal standard corrects for any loss of the analyte during extraction and ionization, ensuring accurate quantification of the unlabeled drug's concentration in the cells.
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| Animal Protocol |
Tilmicosin-d3 is used as an internal standard for in vivo pharmacokinetic studies of tilmicosin. A typical animal study involves administering unlabeled tilmicosin (e.g., 10-25 mg/kg) to healthy cattle, sheep, or mice, via subcutaneous injection or oral administration. Blood samples are collected at various time points (e.g., 0, 0.5, 1, 2, 4, 8, 12, 24, 48, and 72 hours). A fixed amount of Tilmicosin-d3 is added to each plasma sample. After protein precipitation with acetonitrile and centrifugation, the supernatant is injected into an LC-MS/MS system. The deuterated standard allows for accurate determination of tilmicosin concentrations over time, enabling the calculation of key PK parameters like half-life, AUC, and bioavailability.
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| ADME/Pharmacokinetics |
As a stable isotope-labeled internal standard, Tilmicosin-d3 is not a therapeutic agent, and its pharmacokinetics are not a primary focus. However, its PK properties are identical to unlabeled tilmicosin. Tilmicosin is characterized by being orally active but has low bioavailability in some species. It is extensively distributed in the body and has a relatively long elimination half-life in target species, which supports its use as a veterinary antibiotic. It is known for its potential for cardiotoxicity, which limits its use in certain animals. It is formulated for injection or as an oral premix for medicated feed.
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| Toxicity/Toxicokinetics |
The parent compound, tilmicosin, has a known toxicity profile. It has been associated with cardiotoxicity in animals, as evidenced by increased serum cardiac enzyme levels (CK, CK-MB) and markers of oxidative stress (MDA) in mice, indicating acute cardiac injury. It is also toxic to humans if accidentally injected; severe reactions including cardiovascular collapse have been reported. For Tilmicosin-d3, toxicity is not a concern at the trace amounts used as an internal standard (ng/mL to microg/mL). Standard safety precautions for handling antibiotics should be followed (gloves, lab coat, eye protection). It is strictly for research use, not for human or animal use.
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| References | |
| Additional Infomation |
Tilmicosin-d3 is a stable, deuterium-labeled internal standard for the quantitative analysis of the macrolide antibiotic tilmicosin in biological samples using LC-MS or GC-MS. Its primary application is in the field of veterinary drug residue analysis and pharmacokinetic (ADME) studies. The parent drug, tilmicosin, is a calcium channel antagonist and macrolide antibiotic used to treat respiratory infections in livestock. This labeled analog is a research tool, not a drug, and is not intended for clinical or therapeutic use. It is typically stored as a powder at -20degC for long-term stability [40L9-L10].
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| Molecular Formula |
C46H77D3N2O13
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|---|---|
| Molecular Weight |
872.15
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| CAS # |
2714486-61-8
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| Related CAS # |
Tilmicosin;108050-54-0
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| PubChem CID |
162641985
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| Appearance |
White to off-white solid powder
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| Hydrogen Bond Donor Count |
4
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| Hydrogen Bond Acceptor Count |
15
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| Rotatable Bond Count |
12
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| Heavy Atom Count |
61
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| Complexity |
1420
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| Defined Atom Stereocenter Count |
19
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 1.1466 mL | 5.7330 mL | 11.4659 mL | |
| 5 mM | 0.2293 mL | 1.1466 mL | 2.2932 mL | |
| 10 mM | 0.1147 mL | 0.5733 mL | 1.1466 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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