Indocyanine green (ICG) is a tricarbocyanine molecule with a molecular mass of 775 daltons. It is sterile, anionic, water-soluble yet somewhat hydrophobic. The Kodak research laboratories developed ICG dye for near-infrared (NIR) photography in 1955, and the FDA authorised it for therapeutic use in 1959.
The ICG dye is mostly utilised in medical diagnosis to examine the cardiac output, gastric and liver blood flow, and hepatic function as well as in ophthalmic angiography. ICG angiography can show deeper patterns of circulation than fluorescein angiography because these infrared frequencies penetrate retinal layers. Indocyanine Green binds to plasma proteins firmly and is limited to the vascular system. It has a half-life of 150 to 180 seconds and is only eliminated from circulation by the liver, which excretes it in bile juice.
|Name of Product||Indocyanine green|
|Pharmacopoeial Name||Indocyanine green USP-43|
|Synonyms||Foxgreen; IC Green; Cardiogreen; Verde de indocianina; Verde indocianina; Vert d'indocyanine|
|Molar Mass||774.96 g/mol|
|Odor||Odorless or with slight odor|
|1||Appearance and Odor||Olive-Brown, dark green, blue-green, dark blue or bIack powder. Is odorless or has a slight odor. Its solutions are deep emerald- green in color.|
|2||Solubility||Soluble in water and in methanol; practically insoluble in most other organic solvents.|
|3||Solution pH||pH of a solution (1 in 200) is about 6|
|For Sodium||Meets the Requirement — A dense precipitate is formed. Sodium compound impart an intense yellow color to a non-luminous frame.|
|For Sulfate||Meets the Requirement — Solution of sulfates yield a white precipitate that is insoluble in hydrochloric acid and in nitric acid.|
|Test-B||Meets the Requirement — A red color develops within about 4 minutes and, on standing, fades to a pale orange|
|5||Arsenic (Bv ICP-OES)||NMT 8ppm|
|6||Lead (By ICP-OES)||NMT 10 ppm (0.001%)|
|7||Sodium Iodide (by Titration)||NMT 5.0% on the dried basis|
|8||Loss on Drying (LOD)||NMT 6.0%|
|9||Assay (By UV-Vis)||89.0% - 100.0% on the dried basis|
|10||Endotoxin||NMT 7.1 EU/mg|
Medicine may also have some unwanted effects, in addition to its needed effects. It is possible that some of these side effects are not experienced, but if they do, medical treatment may be required.
Other side effects not listed may also occur in some patients. If any of the following side effects occur, speak with your doctor or nurse as soon as possible.
Q. How to dilute Indocyanine Green?
Dilute 25 mg indocyanine green with 10 mL of Sterile Water for Injection (2.5 mg/mL) to see arteries, blood flow, tissue perfusion, and extrahepatic biliary ducts. Dilute up to 40 mg indocyanine green with 2 mL of Sterile Water for Injection (up to 20 mg/mL) for ocular angiograms.
Q. How is Indocyanine Green metabolized & excreted?
Indocyanine Green is metabolized in the liver by the microsomal enzymes and only excreted via the liver and bile ducts in an unconjugated form.
Q. How is Indocyanine Green administrated?
Indocyanine green is administered as a rapid IV bolus for hepatic function studies.
Q. What is the difference between Fluorescein Angiography and Indocyanine Green Angiography?
Indocyanine green dye has a high protein binding capacity (about 98%) and thus can image the choroidal vasculature better than fluorescein angiography. Refer here to know more.