Sibrafiban (RO 48-3657) is an orally bioactive, non-peptide, dual precursor of Ro 44-3888, a selective glycoprotein IIb/IIIa receptor blocker (antagonist). Sibrafiban inhibits platelet aggregation.

Physicochemical Properties

Molecular Formula	C20H28N4O6
Molecular Weight	420.45952
Exact Mass	420.201
CAS #	172927-65-0
PubChem CID	9577986
Appearance	White to off-white solid powder
Density	1.33g/cm3
Index of Refraction	1.598
LogP	1.499
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	9
Heavy Atom Count	30
Complexity	625
Defined Atom Stereocenter Count	1
SMILES	CCOC(=O)COC1CCN(CC1)C(=O)[C@H](C)NC(=O)C2=CC=C(C=C2)/C(=N/O)/N
InChi Key	WBNUCLPUOSXSNJ-ZDUSSCGKSA-N
InChi Code	InChI=1S/C20H28N4O6/c1-3-29-17(25)12-30-16-8-10-24(11-9-16)20(27)13(2)22-19(26)15-6-4-14(5-7-15)18(21)23-28/h4-7,13,16,28H,3,8-12H2,1-2H3,(H2,21,23)(H,22,26)/t13-/m0/s1
Chemical Name	ethyl 2-[1-[(2S)-2-[[4-[(Z)-N'-hydroxycarbamimidoyl]benzoyl]amino]propanoyl]piperidin-4-yl]oxyacetate
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	Sibrafiban inhibits ADP- and TRAP-stimulated fibrinogen binding and microaggregate formation in a concentration-dependent manner, while P-selectin expression remains largely unchanged. Decreased site occupancy from peak to trough by xilafiban does not result in increased platelet activation [3]. The effect of site occupancy by Sibrafiban on platelet activation was assessed using P-selectin expression, fibrinogen binding, and microaggregate formation.
ln Vivo	The effects of Ro 44-3888 on ADP (17 μmol) platelet aggregation and skin bleeding time were investigated by oral administration of xilafiban 0.25 mg/kg/day or 0.5 mg/kg/day to 8 rhesus monkeys for 8 days. Maximal suppression of isolated platelet aggregation and extension of bleeding time by Ro 44-3888 is dose-dependent [1].
References	[1]. Sibrafiban. Drugs. 1999 Feb;57(2):225-30; discussion 231-2. [2]. Pharmacokinetics and pharmacodynamics of sibrafiban alone or in combination with ticlopidine and aspirin. Br J Clin Pharmacol. 2000 Mar;49(3):231-9. [3]. Effects of glycoprotein IIb/IIIa antagonists on platelet activation: development of a transfer method to mimic peak to trough receptor occupancy. Thromb Res. 2002 Sep 15;107(6):303-17.

Solubility Data

Solubility (In Vitro)

DMSO : ~50 mg/mL (~118.92 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.95 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: ≥ 2.08 mg/mL (4.95 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 20.8 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. Solubility in Formulation 3: ≥ 2.08 mg/mL (4.95 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 20.8 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	2.3783 mL	11.8917 mL	23.7835 mL
	5 mM	0.4757 mL	2.3783 mL	4.7567 mL
	10 mM	0.2378 mL	1.1892 mL	2.3783 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.