By influencing TNF-α and IL-6 levels, sinapultide microbubble preparation (2 μg/mL, 5 μg/mL; 24 h) in conjunction with ultrasound (0.5 MHz, 40 s) may significantly aid in the functional recovery of injured AT II cells[2].

Microbubbles (MBs) loaded with sinapultide (0.1 mg; nasal application; collected at 3, 6, 12, and 24 hours after LPS) alleviate lung injury's pulmonary edema and increase lung weight relative to lung diameter in mice with ALI caused by LPS[2].

Absorption, Distribution and Excretion
Administered directly to the lung, where biophysical effects occur at the terminal airways and alveolar surface. No human pharmacokinetic studies have been done to characterize the absorption, distribution, metabolism, or elimination of this drug.

[1]. Braide-Moncoeur O, et al. Peptide-based synthetic pulmonary surfactant for the treatment of respiratory distress disorders. Curr Opin Chem Biol. 2016 Jun;32:22-8.
[2]. Liu D, et al. Sinapultide-Loaded Microbubbles Combined with Ultrasound to Attenuate Lipopolysaccharide-Induced Acute Lung Injury in Mice. Drug Des Devel Ther. 2020 Dec 22;14:5611-5622.

Sinapultide (also known as KL4 peptide) is a synthetic protein used to mimic human lung surfactant protein B. This protein has a weight of 2469.40. Sinapultide is a 21-residue peptide made up of lysine (K) and leucine (L) residues with the sequence KLLLLKLLLLKLLLLKLLLLK (KL4), in aqueous dispersion with the phospholipids DPPC (dipalmitoylphosphatidylcholine), POPG (palmitoyloleoyl-phosphatidylglycerol), and palmitic acid, to create the drug [lucinactant]. The product was originally developed by the Scripps Research Institute, then licensed to Windtree Therapeutics. Windtree Therapeutics plans a phase III trial for Respiratory distress syndrome in 2018. Respiratory distress syndrome (RDS) is a major cause of mortality and morbidity in preterm infants. Surfactant replacement therapy has been commonly used to prevent and treat RDS in these newborns and is now a standard of care. First-generation synthetic surfactants that were previously used, such as Exosurf did not contain any surfactant protein. This large disadvantage was overcome with animal-derived surfactant products which contain specific proteins but are limited, but must be derived from animal sources. This has led to the development of newer synthetic surfactants such as lucinactant (Surfaxin), which contains sinapultide. Phase 3 clinical trials with Surfaxin show promising results with similar efficacy as animal-derived surfactants while avoiding the use of animal-origin products. Windtree is currently developing aerosolized KL4 surfactant to treat RDS in premature infants, and thereafter, to potentially address a range of indications in neonatal, pediatric and adult critical care patient populations.

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Drug Indication
Infant respiratory distress syndrome,,,.

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Mechanism of Action
Endogenous pulmonary surfactant lowers surface tension at the air-liquid interface of the alveolar surfaces during respiration and stabilizes the alveoli against collapse at resting transpulmonary pressures. A deficiency of pulmonary surfactant in premature infants results in RDS. Surfaxin, the drug in which this protein is included, compensates for the deficiency of surfactant and restores surface activity to the lungs of these infants. To explore the mechanisms of protection that this sinapultide offers against RDS, in vitro assays were performed with human and murine endothelial cell monolayers, and polymorphonuclear leukocyte (PMN) transmigration in the presence or absence of KL(4)-surfactant or lipid controls was studied. Based on morphology, histopathology, white blood cell count, percentage of PMNs, and protein concentration in bronchoalveolar lavage fluid, the results that showed KL(4)-surfactant, blocked neutrophil influx into alveoli and thus prevented lung injury. Additionally, in vitro assays demonstrated KL(4)-surfactant decreased neutrophil transmigration at the endothelial cell level. KL(4)-surfactant diminished inflammation and lung permeability when compared with controls in both mouse models of lung injury. Evidence suggests the anti-inflammatory mechanism of the KL(4)-peptide is achieved through inhibition of PMN transmigration through the endothelium.

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Pharmacodynamics
Windtree’s KL4 surfactant technology produces a synthetic surfactant that is structurally similar to human pulmonary surfactant and contains a proprietary synthetic peptide KL4 (sinapultide), cost a 21-amino acid peptide that is formulated to mimic the essential attributes of the human surfactant protein B (SP-B). This protein is one of four surfactant proteins and is the most important for the adequate function of the respiratory system. Windtree has demonstrated in pre-clinical studies that KL4 surfactant may possess certain other beneficial properties, including alteration of the inflammatory process, antimicrobial properties as well as non-immunogenicity.

C126H238N26O22

2467.83

138531-07-4

Sinapultide TFA;2828433-25-4

16132243

White to off-white solid powder

1.1±0.1 g/cm3

2047.1±65.0 °C at 760 mmHg

1191.9±34.3 °C

0.0±0.6 mmHg at 25°C

1.514

14.95

27

28

93

174

4880

21

O=C([C@H](CC(C)C)NC(=O)[C@@H](NC([C@H](CC(C)C)NC(=O)[C@H](CC(C)C)NC([C@@H](NC(=O)[C@@H](NC(=O)[C@@H](N)CCCCN)CC(C)C)CC(C)C)=O)=O)CCCCN)N[C@@H](CC(C)C)C(N[C@H](C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@H](C(N[C@@H](CC(C)C)C(N[C@@H](CC(C)C)C(N[C@H](C(N[C@@H](CCCCN)C(N[C@@H](CC(C)C)C(=O)N[C@H](C(=O)N[C@@H](CC(C)C)C(N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)O)=O)CC(C)C)=O)=O)CC(C)C)=O)=O)=O)CC(C)C)CCCCN)CC(C)C)CC(C)C)=O

QSIRXSYRKZHJHX-TWXHAJHVSA-N

InChI=1S/C126H238N26O22/c1-69(2)53-90(137-106(153)85(132)43-33-38-48-127)114(161)145-98(61-77(17)18)122(169)149-99(62-78(19)20)118(165)141-91(54-70(3)4)110(157)133-86(44-34-39-49-128)107(154)138-95(58-74(11)12)115(162)146-103(66-82(27)28)123(170)150-100(63-79(21)22)119(166)142-92(55-71(5)6)111(158)134-87(45-35-40-50-129)108(155)139-96(59-75(13)14)116(163)147-104(67-83(29)30)124(171)151-101(64-80(23)24)120(167)143-93(56-72(7)8)112(159)135-88(46-36-41-51-130)109(156)140-97(60-76(15)16)117(164)148-105(68-84(31)32)125(172)152-102(65-81(25)26)121(168)144-94(57-73(9)10)113(160)136-89(126(173)174)47-37-42-52-131/h69-105H,33-68,127-132H2,1-32H3,(H,133,157)(H,134,158)(H,135,159)(H,136,160)(H,137,153)(H,138,154)(H,139,155)(H,140,156)(H,141,165)(H,142,166)(H,143,167)(H,144,168)(H,145,161)(H,146,162)(H,147,163)(H,148,164)(H,149,169)(H,150,170)(H,151,171)(H,152,172)(H,173,174)/t85-,86-,87-,88-,89-,90-,91-,92-,93-,94-,95-,96-,97-,98-,99-,100-,101-,102-,103-,104-,105-/m0/s1

(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2,6-diaminohexanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]hexanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]hexanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]hexanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]-4-methylpentanoyl]amino]hexanoic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

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.

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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).

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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)

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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).

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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

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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.

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