Levosalbutamol (also known as levalbuterol), the R-enantiomer of racemic salbutamol (albuterol), is a short-acting β2 adrenergic receptor agonist used in the treatment of asthma and chronic obstructive pulmonary disease (COPD). Salbutamol has been sold as a racemic mixture even though the (R)-enantiomer has nearly all of the beta2-agonist activity. Levosalbutamol (levalbuterol) is an enantiomerically pure (R)-salbutamol formulation that was developed in response to salbutamol's enantioselective disposition and the potential for negative effects associated with (S)-salbutamol.

Physicochemical Properties

Molecular Formula	C13H22CLNO3
Molecular Weight	275.77
Exact Mass	275.128
Elemental Analysis	C, 56.62; H, 8.04; Cl, 12.85; N, 5.08; O, 17.40
CAS #	50293-90-8
Related CAS #	Levalbuterol tartrate; 661464-94-4; Levalbuterol; 34391-04-3; 50293-90-8(HCl)
PubChem CID	123601
Appearance	White to off-white solid powder
Boiling Point	433.5ºC at 760 mmHg
Melting Point	169-171ºC
LogP	2.498
Hydrogen Bond Donor Count	5
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	5
Heavy Atom Count	18
Complexity	227
Defined Atom Stereocenter Count	1
SMILES	CC(C)(C)NC[C@@H](C1=CC(=C(C=C1)O)CO)O.Cl
InChi Key	OWNWYCOLFIFTLK-YDALLXLXSA-N
InChi Code	InChI=1S/C13H21NO3.ClH/c1-13(2,3)14-7-12(17)9-4-5-11(16)10(6-9)8-15;/h4-6,12,14-17H,7-8H2,1-3H3;1H/t12-;/m0./s1
Chemical Name	4-[(1R)-2-(tert-butylamino)-1-hydroxyethyl]-2-(hydroxymethyl)phenol;hydrochloride
Synonyms	Levalbuterol HCl; Levosalbutamol HCl; Xopenex; (R)-albuterol; R-albuterol; R albuterol
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 Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.
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	Levalbuterol hydrochloride (10 μM; 24 hours) causes 11β-HSD1 mRNA expression in airway epithelial cells, but not 11β-HSD2 expression[1]. Levalbuterol (10 μM; 24 hours) hydrochloride decreases NF-κB activity induced by TNF-α and LPS significantly while increasing GRE activation in a manner dependent on 11β-HSD1 in a transformed mouse airway epithelial cell line[1].
ln Vivo	Levalbuterol hydrochloride (subcutaneous injection; 1 mg/kg; 14 days) dramatically reduces pulmonary inflammation in OVA mice, as evidenced by a drop in IgE and eosinophilia[2].
Cell Assay	Cell Line: Murine Club (MTCC) cells Concentration: 10 μM Incubation Time: 24 hours Result: Increased 11β-HSD1 mRNA expression selectively.
Animal Protocol	C57BL/6 female mice with a pulmonary allergic model 1 mg/kg Subcutaneous injection; 1 mg/kg; 14 days
References	[1]. Anti-inflammatory effects of levalbuterol-induced 11β-hydroxysteroid dehydrogenase type 1 activity in airway epithelial cells. Front Endocrinol (Lausanne). 2015 Jan 12;5:236. [2]. (R)-albuterol decreases immune responses: role of activated T cells. Respir Res. 2008 Jan 14;9(1):3.
Additional Infomation	Levalbuterol Hydrochloride is the hydrochloride salt form of levalbuterol, a relatively selective sympathomimetic beta-2 adrenergic receptor agonist with bronchodilator activity. Levalbuterol hydrochloride binds to beta-2 adrenergic receptors in bronchial smooth muscle and activates intracellular adenyl cyclase, thereby increasing the production of cyclic-3', 5'-adenosine monophosphate (cAMP). Increased cAMP levels lead to the activation of protein kinase A, which inhibits the phosphorylation of myosin and lowers intracellular ionic calcium concentrations, resulting in relaxation of bronchial smooth muscles. The increased cyclic AMP concentrations also inhibit the release of inflammatory mediators from mast cells. The R-isomer of albuterol. See also: Levalbuterol (has active moiety).

Solubility Data

Solubility (In Vitro)	H2O: ~100 mg/mL (~362.6 mM)
Solubility (In Vivo)	Solubility in Formulation 1: 100 mg/mL (362.62 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.6262 mL	18.1311 mL	36.2621 mL
	5 mM	0.7252 mL	3.6262 mL	7.2524 mL
	10 mM	0.3626 mL	1.8131 mL	3.6262 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.