Absorption, Distribution and Excretion
100% (IV)
Following a single IV dose of radiolabelled aprotinin, approximately 25-40% of the radioactivity is excreted in the urine over 48 hours. After a 30 minute infusion of 1 million KIU, about 2% is excreted as unchanged drug. After a larger dose of 2 million KIU infused over 30 minutes, urinary excretion of unchanged aprotinin accounts for approximately 9% of the dose.
After intravenous (iv) injection, rapid distribution of aprotinin occurs into the total extracellular space, leading to a rapid initial decrease in plasma aprotinin concentration.
Following a single iv dose of radiolabelled aprotinin, approximately 25-40% of the radioactivity is excreted in the urine over 48 hours. After a 30 minute infusion of 1 million KIU, about 2% is excreted as unchanged drug. After a larger dose of 2 million KIU infused over 30 minutes, urinary excretion of unchanged aprotinin accounts for approximately 9% of the dose.
Animal studies have shown that aprotinin is accumulated primarily in the kidney. Aprotinin, after being filtered by the glomeruli, is actively reabsorbed by the proximal tubules in which it is stored in phagolysosomes.
There are no available studies on the distribution of aprotinin into breast milk.
For more Absorption, Distribution and Excretion (Complete) data for APROTININ (9 total), please visit the HSDB record page.

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Metabolism / Metabolites
Aprotinin is slowly degraded by lysosomal enzymes.
Aprotinin is slowly degraded by lysosomal enzymes. The physiological renal handling of aprotinin is similar to that of other small proteins, e.g., insulin.

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Biological Half-Life
Following this distribution phase, a plasma half-life of about 150 minutes is observed. At later time points, (i.e., beyond 5 hours after dosing) there is a terminal elimination phase with a half-life of about 10 hours.
Following this distribution phase, a plasma half-life of about 150 minutes is observed. At later time points, (i.e., beyond 5 hours after dosing) there is a terminal elimination phase with a half-life of about 10 hours.

[1]. Reversible inhibition of trypsin activity with soybean flour in hide bating process for leather quality improvement. Industrial Crops and Products, Volume 161, March 2021, 113222.

Aprotinin is a protein-based drug that is also known as bovine pancreatic trypsin inhibitor (BPTI). Since it demonstrates the capacity to slow fibrinolysis, it has been employed to reduce bleeding during complex surgery such as heart and liver surgery. For this use, it is typically administered by injection. The goal of using of aprotinin was subsequently to minimize end-organ damage resulting from hypotension due to blood loss in surgery and to reduce the necessity for blood transfusions during surgery. Nevertheless, the drug was formally withdrawn worldwide in May of 2008 after studies confirmed that its use enhanced the risk of complications or death. The substance is consequently made available only for very restricted research use.
Aprotinin is a single chain polypeptide isolated from bovine lung with antifibrinolytic and anti-inflammatory activities. As a broad-spectrum serine protease inhibitor, aprotinin bovine competitively and reversibly inhibits the activity of a number of different esterases and proteases, including trypsin, chymotrypsin, kallikrein, plasmin, tissue plasminogen activator, and tissue and leukocytic proteinases, resulting in attenuation of the systemic inflammatory response (SIR), fibrinolysis, and thrombin generation. This agent also inhibits pro-inflammatory cytokine release and maintains glycoprotein homeostasis.

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Drug Indication
For prophylactic use to reduce perioperative blood loss and the need for blood transfusion in patients undergoing cardiopulmonary bypass in the course of coronary artery bypass graft surgery who are at an increased risk for blood loss and blood transfusion.
FDA Label

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Mechanism of Action
Aprotinin inhibits serine proteases including trypsin, chymotrypsin and plasmin at a concentration of about 125,000 IU/mL, and kallikrein at 300,000 IU/mL. The inhibition of kallikrein inhibits formation of factor XIIa. This inhibits the intrinsic pathway of coagulation and fibrinolysis. Inhibition of plasmin also slows fibrinolysis.
Aprotinin is a broad spectrum protease inhibitor which modulates the systemic inflammatory response (SIR) associated with cardiopulmonary bypass (CPB) surgery. SIR results in the interrelated activation of the hemostatic, fibrinolytic, cellular and humoral inflammatory systems. Aprotinin, through its inhibition of multiple mediators (e.g., kallikrein, plasmin) results in the attenuation of inflammatory responses, fibrinolysis, and thrombin generation.
Aprotinin inhibits pro-inflammatory cytokine release and maintains glycoprotein homeostasis. In platelets, aprotinin reduces glycoprotein loss (e.g., GpIb, GpIIb/IIIa), while in granulocytes it prevents the expression of pro-inflammatory adhesive glycoproteins (e.g., CD11b).
The effects of aprotinin use in ... /cardiopulmonary bypass/ involves a reduction in inflammatory response which translates into a decreased need for allogeneic blood transfusions, reduced bleeding, and decreased mediastinal re-exploration for bleeding.
Aprotinin is thought to improve hemostasis during and after cardiopulmonary bypass by preserving platelet membrane receptors that maintain the adhesive and aggregative capacity of platelets. In addition, aprotinin inhibits fibrinolysis through inhibition of plasmin and plasma and tissue kallikreins. Because of its effects on kallikrein, aprotinin also inhibits activation of the intrinsic clotting system (i.e., contact phase of coagulation), a process that both initiates coagulation and promotes fibrinolysis. The relative contribution of these effects of aprotinin to the drug's therapeutic action remains to be fully elucidated.
For more Mechanism of Action (Complete) data for APROTININ (6 total), please visit the HSDB record page.

6510.051

9035-81-8

169492845

White to off-white solid powder

>100 °C

-25.4

93

97

111

454

16700

57

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ZPNFWUPYTFPOJU-ZRPLRCOFSA-N

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(3R)-4-[[(2S)-1-[[(1R,2aR,4R,5aR,8aR,11aR,13R,14aR,16S,17aR,19S,20aS,25S,26aS,29aS,31S,32aS,34S,35aS,37R,38aS,41aS,42R,44aS,45R,47aR,48S,50aS,51R,53aS,54R,56aR,57S,59aR,60S,62aS,63S,66S,69S,72S,75S,78S,81S,84S,87S,90S,93R)-29a,62a,69,84-tetrakis(4-aminobutyl)-35a,75,78-tris(2-amino-2-oxoethyl)-14a-(3-amino-3-oxopropyl)-8a,41a,72-tribenzyl-50a-[(2S)-butan-2-yl]-53a-[(2R)-butan-2-yl]-47a,48,56a,81,90-pentakis(3-carbamimidamidopropyl)-31,60-bis(2-carboxyethyl)-42-[[2-[[2-[[(1R)-1-carboxyethyl]amino]-2-oxoethyl]amino]-2-oxoethyl]carbamoyl]-57-(carboxymethyl)-11a,45-bis[(1R)-1-hydroxyethyl]-13-[(1S)-1-hydroxyethyl]-66-(hydroxymethyl)-2a,16,38a,44a-tetrakis[(4-hydroxyphenyl)methyl]-26a,32a,59a,63,87-pentamethyl-20a,34-bis(2-methylpropyl)-51-(2-methylsulfanylethyl)-1a,3,4a,7a,9,10a,12,13a,15,16a,18,19a,22a,24,25a,28a,30,31a,33,34a,36,37a,40a,43a,44,46a,47,49a,50,52a,53,55a,56,58a,59,61a,62,64a,65,68,71,74,77,80,83,86,89,92,95,98-pentacontaoxo-5a-propan-2-yl-39,40,66a,67a,70a,71a-hexathia-a,2,3a,6a,8,9a,11,12a,14,15a,17,18a,21a,23,24a,27a,29,30a,32,33a,35,36a,39a,42a,43,45a,46,48a,49,51a,52,54a,55,57a,58,60a,61,63a,64,67,70,73,76,79,82,85,88,91,94,97-pentacontazahexacyclo[91.71.4.454,117.04,8.019,23.025,29]doheptacontahectan-37-yl]amino]-1-oxo-3-phenylpropan-2-yl]amino]-3-[[(2S)-1-[(2S)-2-amino-5-carbamimidamidopentanoyl]pyrrolidine-2-carbonyl]amino]-4-oxobutanoic 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)

H2O: 100 mg/mL

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.)