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Fluorescein Sodium CAS 518-47-8

Molecular Formula: C20H13NaO5

Formula Weight: 356.31

ZSpharmac: Fluorescein Sodium Supplement

Product Name: Fluorescein Sodium
CAS No: 518-47-8
Purity: 99%

Basic Info

Product Name:Fluorescein Sodium
Other Names:Fluorescein Disodium Salt
Place of Origin:Shandong, China
Brand Name:ZSpharmac
Type:Organic Chemical Raw Materials
Appearance:Rust-Orange Powder
EINECS No.:262-390-0
Storage:Store at +5°C to +30°C.
Provide:Fluorescein Sodium MSDS;
Fluorescein Sodium COA

What is Fluorescein Sodium?

Fluorescein angiography (FundusFluoresceinAngiography, FFA) is one of the important methods for the diagnosis and examination of fundus diseases. Fluorescein sodium is a diagnostic drug for fundus angiography. It cannot stain the epithelium such as normal cornea, but it can stain the damaged corneal epithelium green, which can show corneal damage, ulcers and other lesions. Fluorescein sodium Chemicalbook injection is a contrast agent used for FFA. It is a carbohydrate dye. After entering the blood circulation, 80% is bound to serum proteins and red blood cells, and 20% is free in the blood. It does not participate in body metabolism and does not interact with the body. It is a relatively safe contrast agent because it is firmly combined with tissues and has little toxicity. However, in the process of clinical angiography, there are still individual subjects who may have local or systemic adverse reactions, and very few serious cases are even life-threatening.

Fluorescein Sodium Properties:

Melting point 320 °C
storage temp. Store at +5°C to +30°C.
solubility H2O: soluble1mg/mL
Colour Index 45350
form Powder
pka2.2, 4.4, 6.7(at 25℃)
color Rust-orange
PH8.3 (10g/l, H2O, 20℃)
PH RangePink uorescence (4.0) to green uorescence (6.0)
Water Solubility 500 g/L (20 ºC)


Fluorescein Sodium Uses

  1. Fluorescein sodium is used as a fluorescent tracer to study the permeability of the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB) in rodent models.
  2. Using this dye as a probe substrate, sodium fluorescein was used to study the drug transport in hepatocytes mediated by organic anion transporting polypeptide (OATP).
  3. Fluorescein Sodium has also been used to restore in situ solutes into bone by fluorescence after photofading. Fluorescein sodium salt was used as a solute to study microvascular permeability. 

Preparation of Fluorescein Sodium

Nanofluorescein was prepared as follows:
(1) acetylation: add crude product fluorescein sodium and acetic anhydride in the reactor, heat to reflux, react 20-40min, cool down and crystallize, filter, and filter cake is washed with water, and dried to obtain pale yellow diacetylfluorescein crude product; wherein , the mass ratio of described crude product fluorescein sodium and acetic anhydride is 1: 4-6;
(2) recrystallization: with the above-mentioned gained diacetyl fluorescein crude product, with anhydrous organic solvent thermal dissolving, carry out recrystallization, obtain higher purity white crystalline diacetyl fluorescein;
(3) hydrolysis: the crystallization obtained in step (2) is placed in a reactor, an appropriate amount of distilled water is added, stirred, and a sodium hydroxide solution whose mass percentage is 20%-40% is added dropwise, and the reaction is fully stirred until the solid matter is completely dissolved, Continue stirring for 20-30min, cool to room temperature, filter, slowly add dilute hydrochloric acid dropwise to the filtrate, adjust the pH to 1-3, obtain a red precipitate, filter, wash the filter cake with distilled water, and dry to obtain fluorescein;
(4) alkalization: take sodium carbonate and the fluorescein obtained in step (3) to the reactor, the mol ratio of sodium carbonate and fluorescein is 1: 1, add distilled water, heat and stir for 20-40min, and after the reaction is complete, the solution is Evaporate to dryness and vacuum dry to obtain high-purity sodium fluorescein.

Application History of Fluorescein Sodium in Brain Tumor Imaging

Sodium fluorescein was initially mainly used for fundus retinal angiography in ophthalmology, and only later did researchers use it for brain tumor surgery.
According to its application in brain tumor surgery, it can be roughly divided into three stages: the first stage is the naked eye surgery stage, and the brain tumor biopsy operation is guided by fluorescein sodium. This stage started around 1948. Observing 46 patients with brain tumors, the researchers found that fluorescein sodium helped guide the needle biopsy of a variety of brain tumors, including meningiomas, gliomas, and metastases. Unfortunately, in the following decades, reports of fluorescein sodium for brain tumor surgery were rare.
The second stage is the surgical stage under the ordinary microscope, that is, the glioma resection is guided by sodium fluorescein under the white light microscope. Several studies around 2000 have shown that high-dose fluorescein can display the border of glioma more clearly and improve the total resection rate of glioma under the white light field of view of a common operating microscope.
The third stage is the stage of surgery under a microscope equipped with special filters. In 2011, Acerbi et al. used a Pentero microscope (Carl Zeiss, Germany) equipped with a YELLOW 560 special filter to evaluate the safety of fluorescein (5-10 mg/kg)-guided glioma resection. The treatment is prospective Phase II clinical trial. The results of the study showed that there were no adverse reactions related to the use of fluorescein sodium; 75% of the 12 patients with grade IV gliomas achieved contrast-enhanced total tumor resection.
Since then, more and more studies have shown the safety and efficacy of sodium fluorescein-guided resection of malignant gliomas under dedicated filters.

Comparison of Fluorescein Sodium and 5-ALA

Different from the mechanism of fluorescein sodium through the blood-brain barrier to destroy non-specific leakage to the lesion area, another intraoperative fluorescent imaging agent, 5-ALA, can be specifically taken up by glioma cells, and can be metabolized into fluorescence in tumor cells. The metabolite, protoporphyrin, can generate red fluorescence under blue-violet light irradiation to visualize tumors. Although 5-ALA in phase III randomized controlled clinical trials has shown the advantages of increasing the total resection rate of gliomas (65% vs. 36%) and significantly prolonging the progression-free survival of patients (5.1 months vs. 3.6 months), There was no statistically significant difference in overall survival between the two groups (15.2 months vs. 13.5 months). In addition, 5-ALA still has the following shortcomings: it has not been approved by the drug regulatory authorities, the access is limited, and its clinical application also has certain risks; the price is relatively expensive, dozens of times that of fluorescein sodium; the fluorescence mode is suitable for normal brain tissue. Indistinguishable from blood vessels, the lens needs to be switched repeatedly; there is a “bleaching” phenomenon in fluorescence mode, and the fluorescence gradually weakens during tumor resection, which affects the judgment of tumor boundaries; generally, oral administration is required 2-3 hours before surgery, and medication is controlled Poor performance; postoperative patients are at risk of developing photosensitivity reactions, and should avoid sunlight and strong indoor light for 24-48 hours. These shortcomings limit the widespread use of 5-ALA. Relatively speaking, sodium fluorescein has the advantages of easy availability, low price, intravenous administration after induction of anesthesia, convenient use, good intraoperative imaging effect, and the ability to distinguish normal brain tissue and blood vessels well in fluorescence mode. It is a research hotspot and has broad application prospects in improving the resection rate of gliomas and improving the progression-free survival of patients.

Company Profile and Corporate Culture

Company Profile:

ZhiShang Chemical is owned by ZhiShang Group is a professional new-type chemicals enterprise combined into research and development, production and sales .

The company’s competitive product is pharmaceutical raw materials and intermediates (especially carbohydrate derivatives Series), In recent years, the company has made a major breakthrough in food and feed additives, plant extraction, industrial chemicals industry .

The company insists on the spirit of “sincere management, strict quality control, customer as god” , get consistent high praise from customers at home and abroad.

Corporate Culture:

Our Mission
Help China Chemicals to benefit the happiness of human life
Our Vision
Become the most trusted chemical supplier in the world
Our Business Philosophy
Striver – oriented, enrich employees, customer first, deep service, seek development
Our Values
Be prepared for danger in times of peace, forge ahead actively, unity and cooperation, and be brave to fight

About Us

The production base is located in Zhangqiu chemical industry park and Tai’an high-tech chemical industry park. laboratory and workshop in strict accordance with the GMP standard and the product fit national ISO9001 and ISO2000 standards.

“Zhishang” products are exported to Europe, North and South America, the Middle East, Asia Pacific and Africa area, so as to establish a long-term and stable cooperation relationship with customer in the world.

Company Info
  • Business Type: Manufacturer
  • Product Range: Additive , Chemical Auxiliary & Catalyst , Organic Chemicals
  • Products/Service: Organic Intermediate,Inorganic Chemistry, APIs, Dyestuffs And Pigments, Fragrance And Spices, Food Additives
  • Total Employees: 51~100
  • Capital (Million US $): 10000000RMB
  • Year Established: 2016
Production Capacity
  • No. of Production Lines : 8
  • No. of QC Staff : 5 -10 People
  • OEM Services Provided : yes
  • Factory Size (Sq.meters) : 3,000-5,000 square meters
  • Certificate: ISO9001 , CE , GMP , API , MSDS
  • Factory Location : Diao Town Industry Park, Zhangqiu City, Jinan City, Shandong Province, China.


Pre-Sales Service

* Prompt reply and 24 hours online, professional team to provide best price and high quality product.

* Sample testing support.

* Every batch of products will be tested to ensureits quality.

*The packing also can be according the customers` requirment.

*Any inquiries will be replied within 24 hours.

*we provide Commerical Invoice, Packing List, Bill of loading, COA , Health certificate and Origin certificate. If your markets have any special requirements, let us know.


After-Sales Service

*The fact of logistics information monitoring.

* Any questions about the product can be consulted at any time.

*Product has any problem can return.


Do you accept sample order?

We will make samples before mass production, and after sample approved, we’ll begin mass production. Doing 100% inspection during production, then do random inspection before packing.



You can get free samples for some products,you only need to pay the shipping cost or arrange a courier to us and take the samples. You can send us your product specifications and requests,we will manufacture the products according to your requests.

What’s your MOQ?

Our MOQ is 1kg. But usually we accept less quantity such as 100g on the condition that sample charge is 100% paid.

Do you supply product report?

Yes. We’ll give you product analysis report before shipping.

  Is there a discount?

Different quantity has different discount.


1. ≤50kg, Express delivery recommended, usually called as DDU service;

2. ≤500kg, Air shipping recommended, usually called as FOB, CFR, or CIF service;

3. >500kg, sea shipping recommended, usually called as FOB, CFR, or CIF service;

4. For high value products, please select air shipping and express delivery for safe.

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