Biological half-life 2 hours.

Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation
Pyrbuterol has been discontinued in the United States. While there is currently no publicly available data on oral or inhaled pyrbuterol during lactation, data on the related drug terbutaline suggest that very small amounts are expected to be excreted into breast milk. The authors of several reviews and an expert panel agree that the use of such drugs during lactation is acceptable due to the low bioavailability of inhaled bronchodilators and the low maternal serum concentrations after administration.
◉ Effects on Breastfed Infants
No published information found as of the revision date.
◉ Effects on Lactation and Breast Milk
No published information found as of the revision date.

Pirbuterol belongs to the pyridine class of compounds. Pirbuterol is a β2-adrenergic bronchodilator. In vitro and in vivo pharmacological studies have shown that Pirbuterol has a preferential action on β2-adrenergic receptors compared to isoproterenol. Although β2-adrenergic receptors are the major receptors in bronchial smooth muscle, data show that β2 receptors are also present in the human heart at concentrations ranging from 10% to 50%. The exact functions of these receptors are not yet fully understood. The pharmacological action of β-adrenergic agonists, including Pirbuterol, is at least supported by evidence that their mechanism of action involves stimulation of intracellular adenylate cyclase by β-adrenergic receptors. This enzyme catalyzes the conversion of adenosine triphosphate (AIP) to cyclic adenosine monophosphate (cAMP). Elevated cAMP levels are associated with bronchial smooth muscle relaxation and inhibition of the release of immediate-type hypersensitivity mediators from cells, particularly mast cells. Pirbuterol is a β2-adrenergic agonist. The mechanism of action of pibuterol is as a β2-adrenergic agonist. There are reports and data regarding the effects of pibuterol in C. elegans. Pibuterol is a short-acting β-adrenergic receptor agonist with bronchodilatory effects. Pibuterol selectively binds to β-2-adrenergic receptors in bronchial smooth muscle, thereby activating intracellular adenylate cyclase, which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). Elevated cAMP levels lead to bronchial smooth muscle relaxation, relieving bronchospasm, improving mucociliary clearance, and inhibiting the release of immediate-type hypersensitivity mediators from cells, especially mast cells. Indications: For the prevention and reversal of bronchospasm in patients aged 12 years and older with reversible bronchospasm (including asthma).
FDA Label

---

Mechanism of Action
The pharmacological effects of β-adrenergic agonists, including pibuterol, are at least supported by evidence that their mechanism of action involves stimulation of intracellular adenylate cyclase by β-adrenergic receptors. This enzyme catalyzes the conversion of adenosine triphosphate (AIP) to cyclic adenosine monophosphate (cAMP). Elevated cAMP levels are associated with bronchial smooth muscle relaxation and the release of immediate-type hypersensitivity mediators from inhibitory cells, particularly mast cells.

C12H20N2O3

240.2988

240.147

38677-81-5

38029-10-6 (HCl);38677-81-5;65652-44-0 (acetate);

4845

Typically exists as solid at room temperature

1.091

4

5

5

17

230

0

OCC1=C(O)C=CC(C(CNC(C)(C)C)O)=N1

VQDBNKDJNJQRDG-UHFFFAOYSA-N

InChI=1S/C12H20N2O3/c1-12(2,3)13-6-11(17)8-4-5-10(16)9(7-15)14-8/h4-5,11,13,15-17H,6-7H2,1-3H3

6-[2-(tert-butylamino)-1-hydroxyethyl]-2-(hydroxymethyl)pyridin-3-ol

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

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 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).

View More

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 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).

View More

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.)