Foscarnet trisodium hexahydrate is an inhibitor of viral DNA polymerase activity and reversibly inhibits viral replication. The antiherpesviral drug foscarnet trisodium hexahydrate may be used to treat cytomegalovirus retinitis.

Physicochemical Properties

Molecular Formula	CH12NA3O11P
Molecular Weight	300.04
Exact Mass	299.981
CAS #	34156-56-4
Related CAS #	Foscarnet sodium;63585-09-1
PubChem CID	169569
Appearance	Solid powder
Boiling Point	490.7ºC
Flash Point	250.6ºC
Hydrogen Bond Donor Count	6
Hydrogen Bond Acceptor Count	11
Rotatable Bond Count	0
Heavy Atom Count	16
Complexity	103
Defined Atom Stereocenter Count	0
InChi Key	ILRVASBWNRYBFD-UHFFFAOYSA-K
InChi Code	InChI=1S/CH3O5P.3Na.6H2O/c2-1(3)7(4,5)6;;;;;;;;;/h(H,2,3)(H2,4,5,6);;;;6*1H2/q;3*+1;;;;;;/p-3
Chemical Name	trisodium;phosphonatoformate;hexahydrate
Synonyms	Foscarnet trisodium hexahydrate (Trisodium phosphonoformate hexahydrate; Phosphonoformic acid trisodium salt hexahydrate)
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	Foscarnet sodium (Phosphonoformic acid) reproduces the pyrophosphate leaving group of the nucleotide transfer reaction in order to block the human cytomegalovirus DNA polymerase (UL54)[1]. Influenza A Victoria (IC50=29 μM), Influenza B HK (IC50=61 μM), Avian Myeloblastosis Virus (IC50=5-8 μM), HSV-1, many strains (IC50=0.4-3.5 μM), and Foscarnet sodium (Trisodium Phosphoformate) are all inhibited by this medication[2].
References	[1]. Zahn KE, Doublié S, et al. Phosphonoformic acid inhibits viral replication by trapping the closed form of the DNA polymerase. J Biol Chem. 2011 Jul 15;286(28):25246-55. [2]. Oberg B, et al. Antiviral effects of phosphonoformate (PFA, foscarnet sodium).Pharmacol Ther. 1982;19(3):387-415. [3]. Hakki M, et al. Moving Past Ganciclovir and Foscarnet: Advances in CMV Therapy.Curr Hematol Malig Rep. 2020 Jan 24.
Additional Infomation	Trisodium phosphonoformate hexahydrate is the hexahydrate form of trisodium phosphonoformate. It is used as an antiviral agent in the treatment of cytomegalovirus retinitis (CMV retinitis, an inflamation of the retina that can lead to blindness) and as an alternative to ganciclovir for AIDS patients who require concurrent antiretroviral therapy but are unable to tolerate ganciclovir due to haematological toxicity. It has a role as an antiviral drug. It is a hydrate and a one-carbon compound. It contains a trisodium phosphonoformate. Foscarnet sodium is an antiviral prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of cytomegalovirus (CMV) retinitis in individuals with AIDS. Foscarnet sodium is also FDA-approved for the treatment of a certain type of herpes simplex virus (HSV)infection, called acyclovir-resistant mucocutaneousHSV infection, in people with weakened immune systems. CMV diseases—such as those affecting the eye (retinitis)—and HSV diseases can be opportunistic infections (OIs) of HIV. Foscarnet Sodium is the trisodium salt of a synthetic organic analogue of inorganic pyrophosphate with antiviral activity. Foscarnet selectively blocks the pyrophosphate binding site of herpesvirus-specific DNA polymerases at concentrations that do not affect cellular DNA polymerases. This agent does not require phosphorylation by thymidine kinase (TK) or other kinases and therefore is active in vitro against herpes simplex virus (HSV) TK deficient mutants and cytomegalovirus (CMV) UL97 mutants. Because foscarnet crosses the blood brain barrier, it may be used in the treatment of viral infections of the CNS. An antiviral agent used in the treatment of cytomegalovirus retinitis. Foscarnet also shows activity against human herpesviruses and HIV. See also: Foscarnet Sodium (annotation moved to).

Solubility Data

Solubility (In Vitro)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Solubility (In Vivo)

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. Injection Formulations (e.g. IP/IV/IM/SC) 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). 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) Oral Formulations 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). 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 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.3329 mL	16.6644 mL	33.3289 mL
	5 mM	0.6666 mL	3.3329 mL	6.6658 mL
	10 mM	0.3333 mL	1.6664 mL	3.3329 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.