Sodium trimetaphosphate

Sodium trimetaphosphate (Trisodium cyclo-triphosphate) is an orally active, multifunctional compound. Sodium trimetaphosphate serves as a buffer and chelating agent in cosmetics, a starch modifier in food, and can also act as a bone imaging agent. Sodium trimetaphosphate undergoes alkaline hydrolysis, with the rate-limiting first step producing sodium tripolyphosphate; the conversion rate is low when sodium carbonate or silicate is used. Sodium trimetaphosphate can be used in caries-related research^{[1][2][3][4][5]}. In Vitro:Sodium Trimetaphosphate (Trisodium cyclo-triphosphate) (150 min) does not undergo significant hydrolysis in heparinized rabbit blood incubated at 38°C, but induces increased orthophosphate leakage from blood cells compared to controls^[2].
Sodium trimetaphosphate undergoes alkaline hydrolysis to sodium tripolyphosphate in aqueous solutions via a rate-controlled consecutive mechanism, with reaction rate constants ranging from 0.0046 to 0.525 (Mole/L)^-1(Min)^-1, and rates increasing with solids concentration, NaOH ratio, temperature, and sodium sulfate addition^[3].
Sodium trimetaphosphate converts to sodium tripolyphosphate via drum drying of sodium trimetaphosphate-NaOH solutions, without forming sodium acid tripolyphosphate, with tripolyphosphate degradation increasing with excess NaOH^[3].
Sodium trimetaphosphate converts to sodium tripolyphosphate in concentrated Na⁺OH⁻ solutions, with tripolyphosphate stability decreasing with higher Na⁺OH⁻ concentration and temperature; at 50.0°C or 70.0°C with 20% Na⁺OH⁻, tripolyphosphate remains stable, while at 35% or 50% Na⁺OH⁻, tripolyphosphate degrades to pyrophosphate and orthophosphate^[3].
Sodium trimetaphosphate converts to sodium tripolyphosphate via sodium carbonate in 20% solids solutions at 70°C, with a 50% conversion time of 200 minutes, which is far slower than the 2-minute 50% conversion time with stoichiometric sodium hydroxide^[3].
Sodium trimetaphosphate converts to sodium tripolyphosphate in detergent slurries with <60% solids at a rate controlled by the chemical reaction, reaching 97% conversion in 5 minutes at 100°C^[3].
Sodium trimetaphosphate reacts with methyl α-D-glucopyranoside in alkaline medium (pH 10-13.5) to form crosslinked monophosphate (P_c) and grafted monophosphate (P_g) in a ~2:1 ratio via a two-step mechanism involving grafted tripolyphosphate (STPP₉) as an intermediate, with reaction stopping at pH <10 and degradation dominating at pH >13.9^[4].
Sodium trimetaphosphate (0.1 M) crosslinks pullulan in alkaline medium to form hydrogels containing the same phosphorylated species (P_g, P_c, STPP₉) observed in the methyl α-D-glucopyranoside model system, confirming the model's validity for polysaccharide crosslinking^[4].
Sodium trimetaphosphate is highly stable at pH 5.4 but undergoes immediate, temperature-dependent alkaline hydrolysis to tripolyphosphate at pH 13.5, with degradation inhibited at pH ≤11^[4].
Sodium Trimetaphosphate increases the heat sensitivity of Salmonella typhimurium in peptone diluent or complex laboratory media^[2].
Sodium trimetaphosphate does not inhibit planktonic Candida albicans or Streptococcus mutans at the concentrations tested in the MIC assay^[5]. In Vivo:Sodium trimetaphosphate (3650 mg/kg; i.p.; single dose) has an intraperitoneal LD₅₀ of 3650 mg/kg in female Rochester (ex-Wistar) rats, with no associated metabolic acidosis or hypocalcemia^[2].
Sodium trimetaphosphate (10%; dietary; daily; 28 days) causes transient renal tubular necrosis and growth retardation in male weanling rats over 28 days, with the renal lesion resolving by study end^[2].
Sodium trimetaphosphate (0.1-10.0%; dietary; daily; 2 years) causes substantial growth retardation and altered femur composition in weanling rats over 2 years, while lower doses (0.1% and 1.0%) have minimal or transient effects, and no carcinogenic potential is observed^[2].
Sodium trimetaphosphate (0.05%; dietary; daily; across three generations) has no adverse effects on fertility, litter parameters, offspring development, or organ health in rats^[2].
Sodium trimetaphosphate (0.5 g; topical; single 24-hour application) causes no skin irritation in albino rabbits, with a PII of 0^[2].
Sodium trimetaphosphate (46-100 mg/kg; p.o.; single dose) is partially excreted in rat urine, with 40% of the dose recovered as 2% labile phosphate and 38% sodium orthophosphate^[2].
Sodium trimetaphosphate (i.v.; single dose) is rapidly cleared from rabbit plasma, distributes to 12% of body weight, and causes a transient increase in urinary orthophosphate excretion that resolves within 2 hours^[2].