Tizanidine HCl (AB 021 ; AN 021; DS 103-282; BRN-0618691; Sirdalud; Ternelin), the hydrochloride salt of tizanidine, is an alpha2/α2-adrenergic receptor agonist that has been approved for use mainly as a muscle relaxant to treat spasms, cramping, and tightness of muscles.

Physicochemical Properties

Molecular Formula	C9H9CL2N5S
Molecular Weight	290.17
Exact Mass	288.996
Elemental Analysis	C, 37.25; H, 3.13; Cl, 24.43; N, 24.14; S, 11.05
CAS #	64461-82-1
Related CAS #	Tizanidine; 51322-75-9; Tizanidine-d4 hydrochloride; 1188263-51-5
PubChem CID	114869
Appearance	Light yellow to yellow solid powder
Boiling Point	391.2ºC at 760 mmHg
Melting Point	280 °C
Flash Point	190.4ºC
LogP	2.355
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	2
Heavy Atom Count	17
Complexity	300
Defined Atom Stereocenter Count	0
SMILES	ClC1C([H])=C([H])C2C(C=1N([H])C1=NC([H])([H])C([H])([H])N1[H])=NSN=2.Cl[H]
InChi Key	ZWUKMNZJRDGCTQ-UHFFFAOYSA-N
InChi Code	InChI=1S/C9H8ClN5S.ClH/c10-5-1-2-6-8(15-16-14-6)7(5)13-9-11-3-4-12-9;/h1-2H,3-4H2,(H2,11,12,13);1H
Chemical Name	5-chloro-N-(4,5-dihydro-1H-imidazol-2-yl)-2,1,3-benzothiadiazol-4-amine;hydrochloride
Synonyms	BRN0618691; AB 021; AN 021; DS 103-282; BRN-0618691; BRN 0618691; Tizanidine; Tizanidine hydrochloride; Sirdalud; Ternelin.
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

Targets	α2-adrenergic receptor
References	[1]. A practical overview of tizanidine use for spasticity secondary to multiple sclerosis, stroke, and spinal cord injury. Curr Med Res Opin. 2008 Feb;24(2):425-39.
Additional Infomation	Tizanidine hydrochloride is a benzothiadiazole. Tizanidine Hydrochloride is the hydrochloride salt form of tizanidine, an imidazoline derivative structurally similar to clonidine and an adrenergic agonist with muscle relaxant property. Tizanidine stimulates alpha-2 adrenergic receptors in the central nervous system, thereby inhibiting presynaptic release of norepinephrine and increasing the inhibitory effect on alpha motor neurons and motor reflexes. Tizanidine exerts some activity at the postsynaptic excitatory amino acid receptors and imidazoline receptors which may contribute to the overall reduction in facilitation of spinal motor neurons. Overall, tizanidine hydrochloride causes muscle relaxation, reduces spasticity and antinociceptive effects. See also: Tizanidine (has active moiety).

Solubility Data

Solubility (In Vitro)

DMSO: 10~50 mg/mL (34.5~172.3 mM) Water: ~15 mg/mL (~51.7 mM) Ethanol: <1 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 5 mg/mL (17.23 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 50.0 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: ≥ 5 mg/mL (17.23 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 50.0 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.4463 mL	17.2313 mL	34.4626 mL
	5 mM	0.6893 mL	3.4463 mL	6.8925 mL
	10 mM	0.3446 mL	1.7231 mL	3.4463 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.