Difelikefalin

Alias: MR-13A9; CR-845; MR-13A-9; MR13A9; CR845; MR13A-9; trade name Korsuva

Cat No.:V19863 Purity: ≥98%

COA Product Data Instructions for use SDS

Difelikefalin (MR-13A9; CR-845; MR-13A-9; trade name Korsuva) is a novel, peripherally specific, and potent kappa opioid receptor agonist approved in 2021 asan analgesic opiod peptide for the treatment of moderate-to-severe itching.

Difelikefalin Chemical Structure CAS No.: 1024828-77-0
Product category: Opioid Receptor

This product is for research use only, not for human use. We do not sell to patients.

Size	Price	Stock	Qty
5mg
10mg
25mg
50mg
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Other Forms of Difelikefalin:

Difelikefalin HCl

Official Supplier of:

Top Publications Citing lnvivochem Products

Nature 2021, 597(7874):119-125.

Cell 2020,183:1202-1218.e25.

Science Adv 2022: 8, eabm9427.

Nature 597, 119–125 (2021)

Cell Stem Cell 2020,26(6):845-861.e12.

Science Trans Med 2023,15(701):eadd7872.

STTT 2023,8(1):91.

Cell Reports 2023,42(4):112313

Science Trans Med 2023, 15: eadd7872.

Cancer Cell 2021,39(4):529-547.e7.

Cancer Discov 2022,12(4):1106-1127.

Immunity 2023,56(3):620-634.e11.

J Am Chem Soc 2022,144:21831-21836.

Cell 2020,183:1202-1218.e25.

Science Adv 2022:8,eabm9427.

Nature 2021,597(7874):119-125.

Cell 2020,183:1202-1218.e25.

PNAS Nexus 2022,1(3):pgac063.

ACS Nano 2023,17(10):9110-9125.

Biomaterial 2023 Sep16:302:122333.

Product Description
Bioactivity & Protocols
Physicochemical Properties
Solubility Data
Calculators
Clinical Trial Information
Biological Data

Product Description

Difelikefalin (MR-13A9; CR-845; MR-13A-9; trade name Korsuva) is a novel, peripherally specific, and potent kappa opioid receptor agonist approved in 2021 as an analgesic opiod peptide for the treatment of moderate-to-severe itching. In August 2021, difelikefalin received FDA approval for medical use in the US.

Biological Activity I Assay Protocols (From Reference)

Targets	kappa opioid receptor (KOR)
ln Vitro	Difelikefalin (CR-845; FE-202845) does not penetrate the blood-brain barrier. Difelikefalin does not bind to any receptors other than KORs, including mu opioid receptors[1].
References	[1]. Randomized Controlled Trial of Difelikefalin for Chronic Pruritus in Hemodialysis Patients. Kidney Int Rep. 2020 Jan 28;5(5):600-610. [2]. A Phase 3 Trial of Difelikefalin in Hemodialysis Patients With Pruritus. N Engl J Med. 2020 Jan 16;382(3):222-232.

These protocols are for reference only. InvivoChem does not independently validate these methods.

Physicochemical Properties

Molecular Formula	C36H53N7O6
Molecular Weight	679.86
Exact Mass	679.41
Elemental Analysis	C, 63.60; H, 7.86; N, 14.42; O, 14.12
CAS #	1024828-77-0
Related CAS #	413256-25-2 (1HCl); 1024829-44-4 (acetate); 1024828-77-0; 2711717-77-8 (3HCl); 2742623-88-5 (TFA)
Appearance	Solid powder
SMILES	CC(C)C[C@H](C(=O)N[C@H](CCCCN)C(=O)N1CCC(CC1)(C(=O)O)N)NC(=O)[C@@H](CC2=CC=CC=C2)NC(=O)[C@@H](CC3=CC=CC=C3)N
InChi Key	FWMNVWWHGCHHJJ-SKKKGAJSSA-N
InChi Code	InChI=1S/C36H53N7O6/c1-24(2)21-29(32(45)40-28(15-9-10-18-37)34(47)43-19-16-36(39,17-20-43)35(48)49)42-33(46)30(23-26-13-7-4-8-14-26)41-31(44)27(38)22-25-11-5-3-6-12-25/h3-8,11-14,24,27-30H,9-10,15-23,37-39H2,1-2H3,(H,40,45)(H,41,44)(H,42,46)(H,48,49)/t27-,28-,29-,30-/m1/s1
Chemical Name	4-amino-1-[(2R)-6-amino-2-[[(2R)-2-[[(2R)-2-[[(2R)-2-amino-3-phenylpropanoyl]amino]-3-phenylpropanoyl]amino]-4-methylpentanoyl]amino]hexanoyl]piperidine-4-carboxylic acid
Synonyms	MR-13A9; CR-845; MR-13A-9; MR13A9; CR845; MR13A-9; trade name Korsuva
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, avoid exposure to moisture.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility Data

Solubility (In Vitro)	DMSO: ~100 mg/mL (~147.1 mM) H2O: ≥ 100 mg/mL (~147.1 mM)
Solubility (In Vivo)	Solubility in Formulation 1: ≥ 2.5 mg/mL (3.68 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (3.68 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. 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. View More Solubility in Formulation 3: ≥ 2.5 mg/mL (3.68 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. (Please use freshly prepared in vivo formulations for optimal results.)

Solubility (In Vitro)

DMSO: ~100 mg/mL (~147.1 mM)
H2O: ≥ 100 mg/mL (~147.1 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (3.68 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

Solubility in Formulation 2: ≥ 2.5 mg/mL (3.68 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

View More

Solubility in Formulation 3: ≥ 2.5 mg/mL (3.68 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

(Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.4709 mL	7.3545 mL	14.7089 mL
	5 mM	0.2942 mL	1.4709 mL	2.9418 mL
	10 mM	0.1471 mL	0.7354 mL	1.4709 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.

Calculator

Mass

Concentration

Volume

Molecular Weight*

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Molarity Calculator allows you to calculate the mass, volume, and/or concentration required for a solution, as detailed below:

Calculate the Mass of a compound required to prepare a solution of known volume and concentration
Calculate the Volume of solution required to dissolve a compound of known mass to a desired concentration
Calculate the Concentration of a solution resulting from a known mass of compound in a specific volume

See Example

An example of molarity calculation using the molarity calculator is shown below:
What is the mass of compound required to make a 10 mM stock solution in 5 ml of DMSO given that the molecular weight of the compound is 350.26 g/mol?

Enter 350.26 in the Molecular Weight (MW) box
Enter 10 in the Concentration box and choose the correct unit (mM)
Enter 5 in the Volume box and choose the correct unit (mL)
Click the “Calculate” button
The answer of 17.513 mg appears in the Mass box. In a similar way, you may calculate the volume and concentration.

Concentration (Start)

Volume (Start)

Concentration (End)

Volume (End)

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Dilution Calculator allows you to calculate how to dilute a stock solution of known concentrations. For example, you may Enter C1, C2 & V2 to calculate V1, as detailed below:

What volume of a given 10 mM stock solution is required to make 25 ml of a 25 μM solution?
Using the equation C1V1 = C2V2, where C1=10 mM, C2=25 μM, V2=25 ml and V1 is the unknown:

Enter 10 into the Concentration (Start) box and choose the correct unit (mM)
Enter 25 into the Concentration (End) box and select the correct unit (mM)
Enter 25 into the Volume (End) box and choose the correct unit (mL)
Click the “Calculate” button
The answer of 62.5 μL (0.1 ml) appears in the Volume (Start) box

Molecular formula

Total molecular weight

g/mol

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Molecular Weight Calculator allows you to calculate the molar mass and elemental composition of a compound, as detailed below:

Note: Chemical formula is case sensitive: C12H18N3O4 c12h18n3o4
Instructions to calculate molar mass (molecular weight) of a chemical compound:

To calculate molar mass of a chemical compound, please enter the chemical/molecular formula and click the “Calculate’ button.

Definitions of molecular mass, molecular weight, molar mass and molar weight:

Molecular mass (or molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12)
Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol.

Volume (to add to vial)

Mass (in vial)

Desired Reconstitution Concentration

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Reconstitution Calculator allows you to calculate the volume of solvent required to reconstitute your vial.

Enter the mass of the reagent and the desired reconstitution concentration as well as the correct units
Click the “Calculate” button
The answer appears in the Volume (to add to vial) box

In vivo Formulation Calculator (Clear solution)

Step 1: Enter information below (Recommended: An additional animal to make allowance for loss during the experiment)

Dosage mg/kg

Average weight of animals g

Dosing volume per animal μL

Number of animals

Step 2: Enter in vivo formulation (This is only a calculator, not the exact formulation for a specific product. Please contact us first if there is no in vivo formulation in the solubility section.)

% DMSO

% Tween 80

% ddH₂O

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Calculation results

Working concentration： mg/mL；

Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.

Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH₂O，mix and clarify.

Note： (1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.

Clinical Trial Information

NCT Number	Recruitment	interventions	Conditions	Sponsor/Collaborators	Start Date	Phases
NCT05342623	Recruiting	Drug: Difelikefalin 1 mg Oral Tablet Drug: Placebo Oral Tablet	Chronic Kidney Diseases Pruritus	Cara Therapeutics, Inc.	May 17, 2022	Phase 3
NCT05356403	Recruiting	Drug: Difelikefalin 1 mg Oral Tablet Drug: Placebo Oral Tablet	Chronic Kidney Diseases Pruritus	Cara Therapeutics, Inc.	August 26, 2022	Phase 3
NCT05885737	Recruiting	Drug: Difelikefalin Injection Drug: Placebo Injection	Uremic Pruritus	Vifor Fresenius Medical Care Renal Pharma	May 30, 2023	Phase 3
NCT05387707	Recruiting	Drug: difelikefalin 0.25 mg Drug: difelikefalin 0.5 mg	Pruritus Atopic Dermatitis	Cara Therapeutics, Inc.	August 16, 2022	Phase 3
NCT05978063	Recruiting	Drug: difelikefalin 2.0 mg tablets Drug: Placebo tablets	Pruritus Notalgia Paresthetica	Cara Therapeutics, Inc.	August 1, 2023	Phase 2 Phase 3

Biological Data

Change from baseline at week 8 in the weekly mean of the daily 24-hour Worst Itching Intensity Numerical Rating Scale (WI-NRS) scores for difelikefalin versus placebo. Kidney Int Rep . 2020 Jan 28;5(5):600-610.

Changes from baseline at week 8 in quality-of-life (QoL) measures for difelikefalin versus placebo as per Skindex-10 total score (left) and 5-D itch total score (right). Kidney Int Rep . 2020 Jan 28;5(5):600-610.

Percentage of patients per Patient Global Impression of Change categories on 8 weeks of exposure to all difelikefalin combined or placebo. Kidney Int Rep . 2020 Jan 28;5(5):600-610.