Calcium Levofolinate (also known as Calcium Folinate; Calcium levofolinate; CL307782), a calcium salt of and the enantiomerically active form of folinic acid, is widely used as an adjuvant in cancer chemotherapy, e.g. after high-dose methotrexate therapy in osteosarcoma. In patients treated with methotrexate for bone cancer, levoleucovorin is used to treat or prevent the toxic effects of the medication. When treating colorectal cancer that has spread to other body parts, levoleucovorin is also used in combination with fluorouracil (5-FU) and chemotherapy. The cancer itself is not treated by this medication; rather, it only addresses the symptoms of colorectal cancer.

Physicochemical Properties

Molecular Formula	C20H21N7O7.CA
Molecular Weight	511.5
Exact Mass	511.112
Elemental Analysis	C, 46.87; H, 4.33; Ca, 7.82; N, 19.13; O, 21.85
CAS #	80433-71-2
Related CAS #	80433-71-2 (Ca);163254-40-8 (sodium);68538-85-2;
PubChem CID	135403647
Appearance	White to yellow solid powder
Melting Point	240-250ºC
LogP	0
Hydrogen Bond Donor Count	5
Hydrogen Bond Acceptor Count	10
Rotatable Bond Count	7
Heavy Atom Count	35
Complexity	900
Defined Atom Stereocenter Count	1
SMILES	C(N1[C@@H](CNC2C=CC(C(=O)N[C@H](C(=O)O)CCC(=O)O)=CC=2)CNC2NC(=NC(C1=2)=O)N)=O.[Ca]
InChi Key	KVUAALJSMIVURS-QNTKWALQSA-L
InChi Code	InChI=1S/C20H23N7O7.Ca/c21-20-25-16-15(18(32)26-20)27(9-28)12(8-23-16)7-22-11-3-1-10(2-4-11)17(31)24-13(19(33)34)5-6-14(29)30;/h1-4,9,12-13,22H,5-8H2,(H,24,31)(H,29,30)(H,33,34)(H4,21,23,25,26,32);/q;+2/p-2/t12-,13-;/m0./s1
Chemical Name	calcium;(2S)-2-[[4-[[(6S)-2-amino-5-formyl-4-oxo-3,6,7,8-tetrahydropteridin-6-yl]methylamino]benzoyl]amino]pentanedioate
Synonyms	Calcium Folinate; Calcium levofolinate; CL307782; CL 307782; CL-307782
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 Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.
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 Vivo	Levoleucovorin Calcium increases 5-Fluorouracil's toxicity when administered intravenously (6, 20, or 60 mg/kg/day) for four weeks[2].
Animal Protocol	Crj:CD(SD)BR rats (5 weeks)[2] 6, 20 or 60 mg/kg/day i.v.; for 4 weeks (combined with 10 mg/kg/day 5-Fluorouracil)
Toxicity/Toxicokinetics	Effects During Pregnancy and Lactation ◉ Summary of Use during Lactation Leucovorin (folinic acid; 5-formyltetrahydrofolic acid) and its levo- isomer, levoleucovorin, are folic acid derivatives that are normal components of breastmilk. Because leucovorin and levoleucovorin are used as therapeutic agents with potentially toxic drugs such as fluorouracil or methotrexate, the LactMed record of the drug it is used with should be consulted. ◉ Effects in Breastfed Infants Relevant published information was not found as of the revision date. ◉ Effects on Lactation and Breastmilk Relevant published information was not found as of the revision date. Toxicity Data Mouse(iv): LD50 732 mg/kg
References	[1]. National Center for Biotechnology Information. PubChem Compound Summary for CID 135500522, Levoleucovorin calcium. [2]. Effects of levofolinate calcium on subacute intravenous toxicity of 5-fluorouracil in rats. J Toxicol Sci. 1998 May;23 Suppl 1:11-29.
Additional Infomation	Calcium folinate is a tetrahydrofolic acid. Leucovorin Calcium is an active metabolite of folic acid (also called folinic acid and citrovorum factor), which does not require metabolism by dihydrofolate reductase, the molecular target of folate antagonist-type chemotherapeutic drugs. Leucovorin calcium counteracts the toxic effects of these medications, 'rescuing' the patient while permitting the antitumor activity of the folate antagonist. This agent also potentiates the effects of fluorouracil and its derivatives by stabilizing the binding of the drug's metabolite to its target enzyme, thus prolonging drug activity. (NCI04) Levoleucovorin Calcium is a levo isoform of leucovorin calcium with antineoplastic activity. Levoleucovorin is an active metabolite of folic acid, which does not require metabolism by dihydrofolate reductase. This agent counteracts the toxic effects of other folic acid derivative agents, rescuing the patient while permitting the antitumor activity of the folate antagonist. This agent also potentiates the effects of fluorouracil and its derivatives by stabilizing the binding of the drug's metabolite to its target enzyme, thus prolonging drug activity. The active metabolite of FOLIC ACID. Leucovorin is used principally as an antidote to FOLIC ACID ANTAGONISTS. See also: Leucovorin (has active moiety); Leucovorin calcium; pyrimethamine (component of).

Solubility Data

Solubility (In Vitro)

DMSO: <1 mg/mL Water: ~9 mg/mL (~17.6 mM) Ethanol: <1 mg/mL

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	1.9550 mL	9.7752 mL	19.5503 mL
	5 mM	0.3910 mL	1.9550 mL	3.9101 mL
	10 mM	0.1955 mL	0.9775 mL	1.9550 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.