STANNOUS PYROPHOSPHATE

Stannous Pyrophosphate is insoluble in water and soluble in concentrated mineral acids and sodium pyrophosphate.
Stannous Pyrophosphate is a radiopharmaceutical diagnostic agent used for diagnostic imaging scans for the bones, heart, and gastrointestinal tract.
Stannous pyrophosphate is an inorganic chemical compound that belongs to the family of tin(II) salts of pyrophosphoric acid, with the general formula Sn₂P₂O₇. 

CAS Number: 15578-26-4
Molecular Formula: O7P2Sn2
Molecular Weight: 411.36
EINECS Number: 239-635-5

Synonyms: Stannous pyrophosphate, 15578-26-4, Diphosphoric acid, tin(2+) salt (1:2), Ditin pyrophosphate, Tin(2+) pyrophosphate, Stannous pyrophosphate [USAN], Pyro stannous phosphate, MP 4018, Tin(2+) diphosphate (1:2), Ditin(2+) pyrophosphate (4-), Diphosphoric acid, ditin(2+) salt, EINECS 239-635-5, 4DNT29EC86, Phosphoric acid, tin(2+) salt (1:2), Diphosphoric acid, tin salt (1:2), Stannous pyrophosphate (USAN), Pyrophosphoric acid, tin(2+) salt (1:2), DTXSID30889643, STANNOUS PYROPHOSPHATE [MI], MP-4018, STANNOUS PYROPHOSPHATE [WHO-DD], Tin pyrophosphate (6CI,7CI), RefChem:888984, DTXCID301031114, STANNOUS PYROPHOSPHATE [INCI], Pyrophosphoric acid, tin(2+) salt (1:2) (8CI), Tin(II) pyrophosphate, phosphonato phosphate;tin(2+), MFCD00049544, Distannous phosphonato phosphate, Stannouspyrophosphate, Ditin(2+) pyrophosphate (4(-)), UNII-4DNT29EC86, O7P2Sn2, SCHEMBL117707, Tin II pyrophosphate, hydrate, Tin(II) pyrophosphate, 98%, distannous;phosphonato phosphate, GEZAUFNYMZVOFV-UHFFFAOYSA-J, Tin(II) pyrophosphate, AldrichCPR, AKOS025212859, AKOS030241876, D05920, F81527., tinpyrophosphate(6ic,7ci);ditin pyrophosphate;Stannous;tin(ii) phosphate;tin(ii) phosphate (pyro);TechneScan PYP;2,2'-Oxybis[1,3-dioxa-2-phospha-4-stanna(II)cyclobutan-2-one];Pyrophosphoric acid tin(2+) salt

Stannous Pyrophosphate, Sn2P2O7, sp gr 4.009 at 16 °C (60.8 °F), is an amorphous white powder, decomposing at above 400 °C. 
Stannous Pyrophosphate typically appears as a fine, white to off-white crystalline powder that is only sparingly soluble in water but can interact with other compounds in aqueous systems. 
The tin element in this compound is present in the +2 oxidation state, which means it is in a reduced form that can be prone to gradual oxidation to the +4 state under certain conditions, such as exposure to air or moisture.

Because of this chemical structure, stannous pyrophosphate is considered both a source of tin(II) ions and pyrophosphate groups, giving it unique properties compared to other tin salts. 
Stannous Pyrophosphate is frequently used in oral care products, especially in toothpastes, because it can help prevent cavities, reduce tooth sensitivity, and limit the growth of bacteria that cause dental plaque and gum disease. 
In addition to its dental applications, it may also serve as a chemical intermediate, a corrosion inhibitor, or a stabilizer in certain industrial processes.

Stannous Pyrophosphate is thought that technetium Tc-99m pyrophosphate is adsorbed onto the surface of amorphous calcium phosphate deposits 1, insoluble hydroxyapatite crystals, and possibly other organic macromolecules. 
This would result in selective localization to necrotic muscle tissue such as that of a myocardial infarction where calcium deposition has begun as a result of cell damage. 
In areas of altered osteogenesis where hydroxyapatite formation is actively occuring, the surface area to volume ratio is high and favors a greater amount of Stannous Pyrophosphate to the surface of the crystals than in other areas of bone where crystal formation is less active. 

The localization of Stannous Pyrophosphate to these areas allows for their specific radioimaging.
Stannous Pyrophosphate collects in areas of altered osteogenesis and injured myocardium. 
Stannous Pyrophosphate also has an affinity for red blood cells, enabling imaging of blood pools.

Stannous Pyrophosphate is prepared from stannous chloride and sodium pyrophosphate, and used as a caries preventative in toothpaste and as a diagnostic aid in radioactive bone scanning and red-blood-cell labeling.
A radionuclide imaging agent used primarily in scintigraphy or tomography of the heart to evaluate the extent of the necrotic myocardial process. 
Stannous Pyrophosphate has also been used in noninvasive tests for the distribution of organ involvement in different types of amyloidosis and for the evaluation of muscle necrosis in the extremities.

For use as a skeletal imaging agent used to demonstrate areas of altered osteogenesis, and a cardiac imaging agent used as an adjunct in the diagnosis of acute myocardial infarction Label. 
May also be used to image gated blood pools and detect gastrointetinal bleeding.

Melting point : >400 °C (dec.)
Density : 4.01 g/cm³
Storage temp. : Refrigerator
Solubility : Insoluble in H₂O; soluble in concentrated acid solutions
Form : Powder
Specific Gravity : 4.01
Color : White
Odor : Odorless
Water Solubility : Insoluble in water
Merck : 14,8788
Exposure limits : ACGIH TWA 2 mg/m³; NIOSH IDLH 100 mg/m³; TWA 2 mg/m³
LogP : -1 at 20 °C

Adverse reactions such as flushing, hypotension, fever, chills, nausea, vomiting and dizziness, as well as hypersensitivity reactions such as itching and various skin rashes have been noted Label. 
Stannous Pyrophosphate is a radiopharmaceutical and carries the risk of radiation toxicity if inappropriately dosed.
Stannous Pyrophosphate is an inorganic tin(II) salt of pyrophosphoric acid, chemically expressed as Sn₂P₂O₇. 

Stannous Pyrophosphate is a white or off-white crystalline powder with limited solubility in water, but it can form useful dispersions in aqueous systems. 
Stannous Pyrophosphate contains tin in its +2 oxidation state (stannous form), which makes it chemically active but also somewhat unstable, as stannous compounds tend to oxidize to tin(IV) in the presence of air and moisture. 
This instability means that it is often stored and used under controlled conditions to prevent unwanted changes in its chemical properties.

Stannous pyrophosphate is recognized under various chemical names and identifiers (such as USAN, INCI, and EINECS), and it has been studied for many decades for its ability to deliver both tin ions (Sn²⁺) and pyrophosphate anions (P₂O₇⁴⁻). 
This dual functionality gives it unique biological and industrial properties.

In practical applications, stannous pyrophosphate is most widely known for its role in oral health care. 
It is an active ingredient in several therapeutic toothpastes, where it functions as an anti-cavity, anti-plaque, and anti-gingivitis agent. 
The stannous ion is capable of inhibiting the metabolic activity of oral bacteria, thereby reducing acid production and slowing down plaque formation. 

Meanwhile, the pyrophosphate component interferes with the crystallization of calcium phosphate salts, which helps in preventing the formation of tartar (dental calculus) on teeth.
Beyond oral care, stannous pyrophosphate has potential uses in other industrial and chemical processes. 

Stannous Pyrophosphate can act as a corrosion inhibitor for metals, a stabilizer in certain formulations, and even a mild reducing agent in controlled environments. 
In some cases, it is employed as a source of tin(II) in chemical synthesis, since it provides a relatively stable and solid form of this otherwise reactive ion.

Uses Of Stannous Pyrophosphate:
Stannous Pyrophosphate is used to inhibit the formation of volatile sulfur compounds. 
Further, Stannous Pyrophosphate is used for cyanide-free tin coating.
Stannous Pyrophosphate inhibit the formation of volatile sulphur compounds (VSC).

Stannous Pyrophosphate is most widely used in toothpaste and other oral hygiene formulations because of its ability to improve dental health in multiple ways. 
The stannous ion (Sn²⁺) provides antibacterial properties that reduce the growth of harmful bacteria in the mouth, thereby helping to prevent plaque buildup, gingivitis, and bad breath. 
At the same time, the pyrophosphate component works as a tartar-control agent by interfering with the crystallization of calcium phosphate, which slows down or prevents the formation of hard deposits on teeth. 

Unlike some other fluoride or pyrophosphate salts, stannous pyrophosphate provides a synergistic effect by combining antibacterial activity with tartar prevention, making it a valuable ingredient in advanced therapeutic toothpaste formulations.
In addition to reducing plaque and tartar, stannous pyrophosphate helps protect against tooth decay by strengthening enamel and lowering acid production from bacteria. 
The tin ions can also help block exposed dentin tubules in sensitive teeth, thereby reducing tooth sensitivity. 

This makes it an important additive in toothpastes specifically marketed for people who suffer from sensitivity to hot, cold, or sweet foods and beverages.
Outside of oral care, stannous pyrophosphate has applications as a corrosion inhibitor in certain industrial systems. 
The stannous ion can form a thin protective layer on metal surfaces, while the phosphate groups enhance surface passivation. 

This combined action helps slow down the oxidation and degradation of metals, particularly in aqueous or slightly acidic environments.
Stannous pyrophosphate is sometimes used as a chemical intermediate or reagent in laboratory and industrial synthesis. 
Because it is a solid, relatively stable source of tin(II), it can serve as a precursor for the preparation of other stannous compounds or be used in controlled reduction processes. 

In electrochemical or plating applications, tin(II) salts like stannous pyrophosphate may help deposit thin films of tin or tin alloys with specific functional properties.
In certain specialty chemical formulations, stannous pyrophosphate is included as a stabilizer or functional additive, making use of its ability to interact with both metal ions and phosphate groups.
This may include coatings, polymer blends, or protective layers where improved resistance to oxidation or microbial growth is desirable.

The primary and most important application of stannous pyrophosphate is in toothpaste and other dental care products, where it serves multiple therapeutic purposes at the same time. 
Unlike many single-function additives, stannous pyrophosphate provides both antimicrobial protection and tartar control. 
The Stannous Pyrophosphate is able to bind to bacterial cell membranes, interfering with their metabolism and reducing their ability to form acids that erode enamel. 

Meanwhile, the pyrophosphate component disrupts the growth and hardening of calcium phosphate crystals, which directly slows the formation of tartar. 
These combined effects not only reduce cavities and plaque formation but also improve gum health by lowering inflammation and gingivitis risk. 
Because of this dual role, Stannous Pyrophosphate is often found in premium toothpaste formulations that advertise broad-spectrum oral health benefits.

Another important oral care use is in the management of tooth sensitivity, a condition where exposed dentin tubules transmit pain signals when in contact with hot, cold, or acidic foods. 
Stannous Pyrophosphate from the compound can form protective precipitates inside these dentin tubules, effectively blocking them and reducing sensitivity. 
Unlike some fluoride-only formulations that mainly strengthen enamel, stannous pyrophosphate provides an immediate protective barrier against painful sensations, making it suitable for toothpaste marketed specifically for sensitive teeth.

While not primarily a bleaching agent, stannous pyrophosphate indirectly contributes to a whitening effect by preventing the buildup of tartar and plaque, both of which can trap pigments from food and drinks. 
Its ability to keep tooth surfaces cleaner for longer makes it a supporting ingredient in whitening toothpaste formulations, helping maintain brightness over time.
Beyond oral care, stannous pyrophosphate has important industrial uses, particularly as a corrosion inhibitor. 
When applied to metal surfaces or used in certain treatment baths, the tin(II) ions interact with the surface to form a protective barrier, while phosphate groups enhance passivation by reducing the rate of oxidation. 

This makes it useful in cooling systems, water pipes, and protective coatings, especially where metals are exposed to mildly aggressive aqueous environments.
In electrochemistry and materials processing, tin(II) salts like stannous pyrophosphate are sometimes used in electroplating baths for the controlled deposition of tin or tin-based alloys.
The presence of pyrophosphate provides complexation and stabilization, which can help in achieving smoother, more uniform coatings.

Safety Profile Of Stannous Pyrophosphate:
Stannous Pyrophosphate, like many tin(II) compounds, can pose health risks if it is mishandled or if exposure occurs over a prolonged period of time. 
Inhalation of dust or fine particles may irritate the respiratory tract, leading to coughing, shortness of breath, or discomfort in the throat and lungs. 
If ingested in significant amounts, it may cause irritation to the gastrointestinal system, resulting in nausea, vomiting, or abdominal pain. 

Direct skin contact may cause mild to moderate irritation, especially in sensitive individuals, and prolonged or repeated exposure could lead to redness or dermatitis. 
Contact with the eyes can be particularly hazardous, as it may result in irritation, tearing, and discomfort that requires prompt rinsing with water and medical evaluation if symptoms persist.

Although stannous pyrophosphate is not considered one of the most toxic tin compounds, exposure to stannous (Sn²⁺) ions has been associated with certain systemic effects when absorbed in larger quantities. 
Chronic exposure to tin salts may cause headaches, fatigue, dizziness, or digestive disturbances. 
In rare cases, prolonged exposure may affect the liver, kidneys, or nervous system due to the accumulation of tin in body tissues. 

Occupational exposure without proper protective measures could therefore increase the risk of long-term health effects.
Stannous pyrophosphate contains tin in the +2 oxidation state, which is chemically less stable than tin(IV). 
This means the compound can undergo oxidation when exposed to air, heat, or moisture, leading to gradual degradation and loss of activity. 

While this transformation is not usually violent, it can alter the effectiveness of the compound in industrial or pharmaceutical formulations and may generate unwanted byproducts. 
Handling and storage conditions therefore need to minimize exposure to oxygen and humidity.