Absorption, Distribution and Excretion
Patent Blue is selectively absorbed by the lymphatic system. Orally, its absorption rate is extremely low, resulting in limited systemic bioavailability. Patent Blue is primarily excreted in urine and bile. Urinary excretion is more significant; after intravenous injection, urine may even turn blue. Orally, Patent Blue is excreted unchanged in feces. Pharmacokinetic parameters have not been studied. The pharmacokinetic characteristics of this product have not been fully investigated. Metabolism/Metabolites In vitro studies have shown that Patent Blue is not metabolized. Biological Half-Life The elimination half-life is approximately 24–48 hours.

Protein Binding
The patented Blue specifically binds to albumin, enabling it to cross the mammary lymphatic system.

[1]. Mennel S, et al. Patent blue: a novel vital dye in vitreoretinal surgery. Ophthalmologica. 2006;220(3):190-3.
[2]. Barranger E, et al. Laparoscopic sentinel lymph node procedure using a combination of patent blue and radioisotope in women with cervical carcinoma. Cancer. 2003 Jun 15;97(12):3003-9.

Sulfamide Blue is a dark greenish-black powder. (NTP, 1992) Patent Blue is an organic molecular entity. Patent Blue is an aniline dye and one of the most commonly used dyes. It is the sodium or calcium salt of diethylammonium hydroxide inner salt. Its chemical name is (4-(α-(p-(diethylamino)phenyl)-2,4-disulfonylbenzyl)-2,5-cyclohexadiene-1-ylidene)diethylammonium hydroxide. Patent Blue was developed by Guerbet and approved by Health Canada on December 31, 1979. Its isomer, isoflavone, has the same indications in the United States as Patent Blue.

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Pharmaceutical Indications
Patent Blue is used in combination with radioactive tracers to label lymphatic and arterial blood supply areas, and to label sentinel lymph nodes before biopsy in patients with operable breast cancer and clinically negative lymph nodes. Patent Blue is also used in the textile, paper, agricultural, and cosmetic industries.
FDA Label

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Mechanism of Action
The specific binding of Patent Blue allows it to move freely within the breast lymphatic system, providing a less invasive staging method. Patent Blue forms a complex with albumin, which is absorbed by regional afferent lymphatic vessels, thus identifying sentinel lymph nodes. A sentinel lymph node is the first lymph node in a series of lymph nodes to which cancer cells are most likely to have spread. Identification of sentinel lymph nodes allows doctors to stage cancer by observing whether it has spread to nearby lymph nodes. It is worth noting that several dyes associated with pararosaniline, including Blue VRS, exhibit genotoxicity, and this activity is related to the presence of a substituted or unsubstituted amino group at the para-position of the N+ amino group at the R3 position. Therefore, Patent Blue is not genotoxic. This dye contains a sulfonic acid group at this position, which may interfere with the activation of the N+ atom.

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Therapeutic Use
Dye
Laboratory Use: The blue test is designed to show total or partial lymphedema. Intolerance after dye injection is rare, but can sometimes be severe, and users should be aware of this possibility.

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Pharmacodynamics
It has been reported that approximately 1% of patients experience hypersensitivity reactions after using Patent Blue. It also produces a localized blue color, making Patent Blue a sensitive and specific option for detecting lymph node micrometastases.

C27H31N2NAO6S2

566.66

566.152

129-17-9

8507

VIOLET POWDER
Dark bluish-green powder

290ºC

5.923

0

7

7

38

1040

0

[Na+].CCN(C1=CC=C(C(C2=CC=C(S([O-])(=O)=O)C=C2S([O-])(=O)=O)=C2C=CC(=[N+](CC)CC)C=C2)C=C1)CC |t:22,26|

SJEYSFABYSGQBG-UHFFFAOYSA-M

InChI=1S/C27H32N2O6S2.Na/c1-5-28(6-2)22-13-9-20(10-14-22)27(21-11-15-23(16-12-21)29(7-3)8-4)25-18-17-24(36(30,31)32)19-26(25)37(33,34)35;/h9-19H,5-8H2,1-4H3,(H-,30,31,32,33,34,35);/q;+1/p-1

sodium;4-[[4-(diethylamino)phenyl]-(4-diethylazaniumylidenecyclohexa-2,5-dien-1-ylidene)methyl]benzene-1,3-disulfonate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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

DMSO: 125 mg/mL (220.59 mM)
H2O: 1 mg/mL (1.76 mM)

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.)