Danirixin (formerly known as GSK-1325756; GSK1325756) is a novel, potent small molecule CXCR2 antagonist being developed as a potential anti-inflammatory drug for COPD. It is a selective, high-affinity and reversible CXCR2 antagonist with IC50 of 12.5 nM for CXCL8. Danirixin, an oral CXCR2 antagonist, has been shown to inhibit agonist-induced neutrophil activation in a dose-dependent manner after single and repeated once-daily oral administration. This suggests that the drug may be useful in treating inflammatory diseases where neutrophils predominate. In many acute and chronic inflammatory diseases, there is an important role for excessive neutrophil activation and presence. One key player in regulating neutrophil extravasation and activation is the CXCR2 chemokine receptor. One possible strategy for decreasing neutrophil migration and activation is selective antagonistic action on the CXCR2 receptor.

Physicochemical Properties

Molecular Formula	C19H21CLFN3O4S
Molecular Weight	441.90
Exact Mass	441.092
Elemental Analysis	C, 51.64; H, 4.79; Cl, 8.02; F, 4.30; N, 9.51; O, 14.48; S, 7.25
CAS #	954126-98-8
Related CAS #	954126-98-8
PubChem CID	24780598
Appearance	White to off-white solid powder
Density	1.5±0.1 g/cm3
Boiling Point	533.1±50.0 °C at 760 mmHg
Flash Point	276.2±30.1 °C
Vapour Pressure	0.0±1.5 mmHg at 25°C
Index of Refraction	1.638
LogP	3.93
Hydrogen Bond Donor Count	4
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	4
Heavy Atom Count	29
Complexity	677
Defined Atom Stereocenter Count	1
SMILES	S([C@@H]1CNCCC1)(C1C(Cl)=CC=C(NC(=O)NC2C=CC=C(F)C=2C)C=1O)(=O)=O
InChi Key	NGYNBSHYFOFVLS-LBPRGKRZSA-N
InChi Code	InChI=1S/C19H21ClFN3O4S/c1-11-14(21)5-2-6-15(11)23-19(26)24-16-8-7-13(20)18(17(16)25)29(27,28)12-4-3-9-22-10-12/h2,5-8,12,22,25H,3-4,9-10H2,1H3,(H2,23,24,26)/t12-/m0/s1
Chemical Name	1-[4-chloro-2-hydroxy-3-[(3S)-piperidin-3-yl]sulfonylphenyl]-3-(3-fluoro-2-methylphenyl)urea
Synonyms	Danirixin; GSK-1325756; GSK1325756; GSK 1325756
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

Targets	CXCL8-CXCR2 ( IC50 = 12.5 nM )
ln Vitro	In vitro activity: Danirixin has a great affinity for CXCR2, binding to human CXCR2 expressed in Chinese hamster ovary cells (CHO) with a negative log of the 50% inhibitory concentration (pIC50) of 7.9 and 78-fold selectivity over binding to CXCR1 expressed in CHO. With a KB of 6.5 nM and antagonist potency (pA2) of 8.44, danirixin is a competitive antagonist against CXCL8 in Ca2+-mobilization assays. It is also fully reversible in washout experiments over a 180-minute duration[1].
ln Vivo	Danirixin inhibits CD11b upregulation in rat and human whole-blood experiments measuring neutrophil activation by surface CD11b expression after CXCL2 (rat) or CXCL1 (human) challenge, with pIC50s of 6.05 and 6.3, respectively. With median effective doses (ED50s) of 1.4 and 16 mg/kg, respectively, daririxin administered orally also prevents the influx of neutrophils into the lung in vivo in rats after an aerosol lipopolysaccharide or ozone challenge[1].
Enzyme Assay	It is a selective, high-affinity and reversible antagonist of CXCR2 with IC50 of 12.5 nM for CXCL8.
Animal Protocol	10 mg, 25 mg, 50 mg, 100 mg, and 200 mg There were no serious adverse events and no adverse events considered to be of clinical relevance. There were no withdrawals due to adverse events. Systemic exposure following single doses of danirixin 10 mg, 25 mg, 50 mg, 100 mg, and 200 mg increased with increasing dose. Engagement of pharmacology was demonstrated as inhibition of ex-vivo CXCL1-induced CD11b expression on peripheral blood neutrophils when compared to placebo (approximately 50% for 50 mg and 100 mg danirixin, and 72% at 200 mg). There was a 37% decrease in Cmax and a 16% decrease in AUC (0-∞) following administration of danirixin in the presence of food. Cmax also decreased by 65% when danirixin 100 mg was administered following omeprazole 40 mg once daily for 5 days. The AUC (0-∞) and Cmax were 50% lower in elderly subjects compared with younger subjects.
References	[1]. J Pharmacol Exp Ther . 2017 Aug;362(2):338-346. [2]. BMC Pharmacol Toxicol. 2015, 16: 18. [3]. Drug Metab Dispos . 2010 Mar;38(3):405-14. [4]. Diabetes Obes Metab . 2010 Nov;12(11):1004-12. [5]. Nutrients . 2021 Nov 15;13(11):4088.
Additional Infomation	Danirixin has been used in trials studying the treatment and basic science of Virus Diseases, Nutritional Status, Pulmonary Disease, Chronic Obstructive, and Infections, Respiratory Syncytial Virus.

Solubility Data

Solubility (In Vitro)

DMSO: ~8 mg/mL (~18.1 mM) Water: <1mg/mL Ethanol: <1mg/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	2.2630 mL	11.3148 mL	22.6296 mL
	5 mM	0.4526 mL	2.2630 mL	4.5259 mL
	10 mM	0.2263 mL	1.1315 mL	2.2630 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.