Absorption, Distribution and Excretion
Potassium salts are readily absorbed from the gastrointestinal tract. In some animals, the small intestine may absorb net phosphorus, but in horses, net phosphorus absorption is primarily accomplished by the colon. Potassium is mainly excreted through the kidneys. Potassium is primarily distributed intracellularly, but intravascular concentration is the main cause of toxicity. Phosphates can be rapidly removed by dialysis. Potassium salts are readily absorbed from the gastrointestinal tract. …Potassium is primarily excreted through the kidneys. /Potassium Salts/ In some animals, the small intestine may absorb net phosphorus, but in horses, net phosphorus absorption is primarily accomplished by the colon. /SRP: Phosphate/ /Orthophosphates are absorbed from the gastrointestinal tract and secreted in small amounts into it. Phosphate transport from the intestinal lumen is an active, energy-dependent process influenced by a variety of factors. …Vitamin D can stimulate phosphate absorption; this effect has been reported to precede its effect on calcium ion transport. In adults, approximately two-thirds of ingested phosphates are absorbed, and almost all absorbed phosphates are excreted in the urine. In growing children, the phosphate balance is positive. Children have higher plasma phosphate concentrations than adults. This "hyperphosphatemia" reduces the affinity of hemoglobin for oxygen and is considered an explanation for physiological "anemia" in children. /Phosphate/

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Metabolism/Metabolites
Phosphate is a major intracellular anion involved in energy supply for metabolism and participates in important metabolic and enzymatic reactions in almost all organs and tissues.

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Biological Half-Life
In healthy children, the half-life of excess phosphate is 4.8 to 10.6 hours, while in children with renal insufficiency, the half-life is prolonged to 17 hours.

Protein Binding
Phosphate binds very little to proteins and is highly concentrated within cells (intracellular concentration is 100 times higher than serum concentration). Children have higher plasma phosphate concentrations than adults.

[1]. Effect of dipotassium hydrogen phosphate on thermodynamic properties of glycine and l-alanine in aqueous solutions at different temperatures. The Journal of Chemical Thermodynamics, 2012, 53: 86-92.

[2]. Pharmaceutical excipients - quality, regulatory and biopharmaceutical considerations. Eur J Pharm Sci. 2016 May 25;87:88-99.

Dipotassium hydrogen phosphate (DHP) is a potassium salt, specifically a dipotassium salt of phosphate. It has buffering properties. It is both a potassium salt and an inorganic phosphate. DHP (K₂HPO₄) is a highly water-soluble salt, commonly used as a fertilizer and food additive, serving as both a source of phosphorus and potassium and a buffer. DHP is the dipotassium form of phosphate and can be used as an electrolyte supplement and has radioprotective properties. Oral administration of potassium phosphate can block the absorption of the radioactive isotope phosphorus-32 (P-32). Pharmacological Indications: DHP is used as an additive in artificial creamers, powdered beverages, mineral supplements, and starter cultures. It is used in non-dairy creamers to prevent coagulation. DHP is also used in the preparation of buffer solutions and in the production of tryptone soy agar, which is used to prepare bacterial culture agar plates. Mechanism of Action: Once phosphates enter body fluids and tissues, their pharmacological effects are minimal. If phosphate ions enter the intestines, the absorbed phosphate is rapidly excreted. If large amounts of phosphate are administered via this route, most may not be absorbed. Due to this property, phosphates have a laxative effect and are therefore used as mild laxatives. Phosphate has minimal pharmacological effect once it enters body fluids and tissues. If phosphate ions enter the intestines, the absorbed phosphate is rapidly excreted. If large amounts of phosphate are administered via this route, most may not be absorbed. Due to this property, phosphates have a laxative effect and are therefore used as mild laxatives. Inorganic phosphate poisoning has been reported in both adults and children after taking phosphate-containing laxatives. Large intakes of sodium dihydrogen phosphate can lower urine pH. Excessive intravenous or oral administration of phosphate can lead to poisoning by reducing the concentration of circulating Ca²⁺ and forming calcium phosphate precipitates in soft tissues. /Phosphate/

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Therapeutic Uses
Laxatives
This study investigated factors affecting the solubility of calcium phosphate in neonatal parenteral nutrition solutions. Six neonatal parenteral nutrition solutions were prepared using Aminosyn or FreAmine II, along with varying concentrations of amino acids and glucose. Phosphorus (in the form of potassium dihydrogen phosphate and dipotassium hydrogen phosphate) and calcium (in the form of 10% calcium gluconate) were added at concentrations ranging from 2.5–100 meq/L and 2.5–100 mmol/L, respectively. Two parallel samples were prepared and analyzed after heating in a 37°C water bath for 20 minutes or after incubation at 25°C for 18 hours, followed by heating in a 37°C water bath for 30 minutes. Precipitates were detected visually and spectrophotometrically, and pH was measured. Lipid emulsions were added to both FreAmine II solutions at a ratio of 7.5:1 (parenteral nutrition solution: lipid), and the resulting pH was measured. Time and temperature both affected the solubility of calcium phosphate in all test solutions. Precipitation curves were plotted for each solution based on the amount of calcium added versus the amount of phosphate added. Amino acid and glucose concentrations affect the pH of the solution; the pH increase of a 1% FreAmine II solution is greater than that of a 2% FreAmine II solution when a lipid emulsion is added. In certain specific solutions, up to 120 mg/kg of calcium and 55 mg/kg of phosphate can be administered daily, equivalent to the daily accumulation of these minerals in late pregnancy. The precipitation curves and limitations described in this article help to ensure the safe intravenous infusion of calcium and phosphorus into newborns.
Surgical Saline Large Volume Laxatives

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Drug Warnings
Oral administration is safer, but serum electrolyte levels and renal function must be closely monitored. Nausea, vomiting, and diarrhea may occur and may be dose-related. Concomitant use with antacids containing aluminum and/or magnesium should be avoided, as they may bind to phosphate and prevent its absorption (calcium antacids may also bind to phosphate, and these drugs are generally not considered for use in patients with hypercalcemia).
Phosphate should not be taken by patients with impaired renal function or hyperphosphatemia. Patients with alkaline urine due to urinary tract infections should not take phosphates, as the increased concentration of calcium and phosphate in alkaline urine increases the risk of calcium phosphate stones. Intravenous phosphate administration is extremely dangerous. There have been reports of hypocalcemia, hypotension and shock, myocardial infarction, tetany, and acute renal failure, and even death. Calcium phosphate deposition in the kidneys, heart, lungs, and blood vessels can also be fatal. Therefore, intravenous treatment for hypercalcemia is inappropriate. Phosphates should not be given to patients with impaired renal function or hyperphosphatemia. Phosphates should also not be given to patients with alkaline urine due to urinary tract infections, as the increased concentration of calcium and phosphorus in alkaline urine increases the risk of calcium phosphate stones. Phosphates should be administered in potassium form, not sodium form, because sodium salts cause blood volume expansion and inhibit phosphate reabsorption, thus negating the therapeutic effect. The most common adverse reaction to phosphates is diarrhea. Patients with kidney stones may pass old stones when starting phosphate treatment; this possibility should be explained to them. Phosphates are contraindicated in patients with infectious stones and those whose renal function is below 30% of normal. /Orthophosphate/

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Pharmacodynamics
Phosphates are the main intracellular anions, involved in energy supply for metabolism, and participate in important metabolic and enzymatic reactions in almost all organs and tissues. Phosphates regulate calcium concentration, buffer acid-base balance, and play an important role in the kidney's excretion of hydrogen ions.

HK2O4P

174.18

173.888

7758-11-4

16068-46-5 (Parent)

24450

White crystals
Colorless or white granules or powder

2,44 g/cm3

158ºC at 760 mmHg

340 °C

1

4

0

7

46.5

0

[K+].[K+].P(=O)([O-])([O-])O[H]

ZPWVASYFFYYZEW-UHFFFAOYSA-L

InChI=1S/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2

dipotassium;hydrogen phosphate

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)

H2O: 50 mg/mL (287.06 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.)