Absorption, Distribution and Excretion
Oral doses of benzydamine are well absorbed and plasma drug concentrations reach a peak fairly rapidly and then decline with a half-life of approximately 13 hours. When applied topically, although the local drug concentrations are relatively large, the systemic absorption of topically applied benzydamine is relatively low compared to oral doses. This low topical absorption contributes to a decreased potential for any systemic drug side-effects when benzydamine is administered in this way.
The relatively high lipid solubility of the weak base benzydamine is thought to be associated with considerable passive resorption within the renal tubule, which suggests that only approximately 5% of benzydamine is excreted unchanged in the urine. At the same time however, other studies have suggested that considerably larger amounts (50-65%) of the drug is excreted unchanged in urine. While several inactive oxidized metabolites of benzydamine are excreted in urine, the benzydamine N-oxide metabolite can remain in plasma and demonstrate a half-life that is longer than the parent benzydamine compound. Nevertheless, it is generally believed that excretion occurs mainly through urine and is mostly in the form of inactive metabolites or conjugation products.
The volume of distribution of benzydamine is 10 L.
Benzydamine demonstrateas a systemic clearance of 170 ml/min.

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Metabolism / Metabolites
Benzydamine is primarily metabolized by oxidation, dealkylation, and conjugation into hydroxy, dealkylated, and N-oxide metabolites. In general, however, when used at the recommended doses the levels at which benzydamine is absorbed or exposed into the body are usually not sufficient to produce systemic pharmacological effects [L

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Biological Half-Life
Approximately 13 h after oral administration, with a terminal half life of about 7.7 h.

Protein Binding
Benzydamine exhibits < 20% plasma protein binding after oral administration.

[1]. Quane PA, Pharmacology of benzydamine. Inflammopharmacology. 1998;6(2):95-107

Benzydamine is a member of the class of indazoles carrying benzyl and 3-(dimethylamino)propyl groups at positions 1 and 3 respectively. A locally-acting nonsteroidal anti-inflammatory drug that also exhibits local anaesthetic and analgesic properties. It has a role as a central nervous system stimulant, a non-steroidal anti-inflammatory drug, a hallucinogen, a local anaesthetic and an analgesic. It is a member of indazoles, an aromatic ether and a tertiary amino compound. It is a conjugate base of a benzydamine(1+).
Benzydamine (also known as Tantum Verde or Difflam), available as the hydrochloride salt, is a locally-acting nonsteroidal anti-inflammatory drug (NSAID) with local anaesthetic and analgesic properties. It is used topically for pain relief and anti-inflammatory treatment of the mouth, throat, or muscoskeletal system. Although the indazole analogue benzydamine is a non-steroidal anti-inflammatory drug (NSAID), it has various physicochemical properties and pharmacologic activities that are different from those of traditional aspirin-like NSAIDs but facilitate benzydamine's mechanism of action as an effective locally-acting NSAID with local anaesthetic and analgesic properties. Moreover, unlike aspirin-like NSAIDs which are acids or metabolised to acids, benzydamine is in fact a weak base.
A benzyl-indazole having analgesic, antipyretic, and anti-inflammatory effects. It is used to reduce post-surgical and post-traumatic pain and edema and to promote healing. It is also used topically in treatment of RHEUMATIC DISEASES and INFLAMMATION of the mouth and throat.

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Drug Indication
Available predominantly as a liquid mouthwash, oromucosal spray, or topical cream, benzydamine is most frequently employed as a locally acting analgesic and anti-inflammatory treatment for the relief of painful inflammatory conditions. When formulated as a mouthwash or spray, benzydamine may be used to treat traumatic conditions like pharyngitis following tonsillectomy or the use of a naso-gastric tube, inflammatory conditions like pharyngitis, aphthous ulcers and oral ulceration due to radiation therapy, dentistry operations and procedures, or more general conditions like sore throat, sore tongue, sore gums, mouth ulcers, or discomfort caused by dentures. When used as a topical cream, benzydamine may be employed to relieve symptoms associated with painful inflammatory conditions of the muscolo-skeletal system including acute inflammatory disorders such as myalgia and bursitis or traumatic conditions like sprains, strains, bruises, sore muscles, stiff joints, or even the after-effects of fractures.

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Mechanism of Action
Despite being categorized as a non-steroidal anti-inflammatory drug (NSAID), benzydamine demonstrates various mechanisms of action that differ from those of traditional aspirin-like NSAIDs. In particular, benzydamine predominantly acts by inhibiting the synthesis of pro inflammatory cytokines like tumour necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) without largely affecting other pro inflammatory cytokines (ie. such as IL-6 and IL-8) or anti-inflammatory cytokines (ie. like IL-10 or IL-1 receptor antagonist). Moreover, benzydamine is largely a weak inhibitor of prostaglandin synthesis as it has been shown to effectively inhibit cyclooxygenase (COX) and lipoxygenase enzyme activity only at concentrations of 1mM or greater. Considering most contemporary usages of benzydamine are topical applications that are generally not well absorbed through the skin and/or non-specialized mucosae, benzydamine does not often achieve the kind of absorption or blood concentrations necessary to cause any extraneous distant systemic effects or COX inhibition, allowing it to localize its action. Additionally, it is also hypothesized that benzydamine is capable of inhibiting the oxidative burst of neutrophils and membrane stabilization. These actions are exhibited by the substance’s ability to inhibit the release of granules from neutrophils and to stabilize lysosomes. Furthermore, benzydamine is capable of a local anaesthetic effect that may be related to its capability for inhibiting the release of inflammatory mediators like substance P and calcitonin gene related peptide from sensory nerve endings. Since substance P is capable of causing the release of histamine from mast cells, benzydamine’s prevention of substance P release further contributes to an anti-inflammatory effect. Benzydamine also demonstrates a non-specific antibacterial activity against various bacterial strains that are resistant to broad-spectrum antibiotics such as ampicillin, chloramphenicol, and tetracycline at concentrations of about 3 mmol/L. Combinatorial use of benzydamine and other antibiotics like tetracycline and chloramphenicol are also synergistic against antibiotic resistant strains of *Staphylococcus aureus* and *Pseudomonas aeruginosa*.

C19H23N3O

309.41

309.184

642-72-8

132-69-4 (mono-hydrochloride)

12555

Typically exists as solid at room temperature

1.1±0.1 g/cm3

474.4±35.0 °C at 760 mmHg

320°F

240.7±25.9 °C

0.0±1.2 mmHg at 25°C

1.580

3.78

0

3

7

23

344

0

CN(C)CCCOC1=NN(CC2=CC=CC=C2)C3=CC=CC=C31

CNBGNNVCVSKAQZ-UHFFFAOYSA-N

InChI=1S/C19H23N3O/c1-21(2)13-8-14-23-19-17-11-6-7-12-18(17)22(20-19)15-16-9-4-3-5-10-16/h3-7,9-12H,8,13-15H2,1-2H3

3-(1-benzylindazol-3-yl)oxy-N,N-dimethylpropan-1-amine

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

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

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.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*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).

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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)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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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).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)