Robalzotan HCl (NAD-299 HCl) is a potent and specific inhibitor of 5-Hydroxytryptamine 1A (5-HT1A). Robalzotan HCl increases the firing rate of 5-HT cells. Robalzotan HCl induces 5-HT1A receptor occupancy. Robalzotan HCl may be used for studying cholinergic defects in the central nervous system.

Physicochemical Properties

Molecular Formula	C18H24CLFN2O2
Molecular Weight	354.846767425537
Exact Mass	354.151
CAS #	184674-99-5
PubChem CID	90488823
Appearance	White to off-white solid powder
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	4
Heavy Atom Count	24
Complexity	438
Defined Atom Stereocenter Count	1
SMILES	Cl.FC1=CC=C(C(N)=O)C2=C1OC[C@@H](C2)N(C1CCC1)C1CCC1
InChi Key	GSZJANKLCPHEEX-BTQNPOSSSA-N
InChi Code	InChI=1S/C18H23FN2O2.ClH/c19-16-8-7-14(18(20)22)15-9-13(10-23-17(15)16)21(11-3-1-4-11)12-5-2-6-12/h7-8,11-13H,1-6,9-10H2,(H2,20,22)1H/t13-/m1./s1
Chemical Name	(R)-3-(dicyclobutylamino)-8-fluorochromane-5-carboxamide hydrochloride
Synonyms	NAD-299 HCl NAD299 HClNAD 299 HCl NAD 299 Hydrochloride NAD299 HydrochlorideNAD-299 hydrochloride
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
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 Vivo	The effects of citalopram (300 µg/kg iv) or paroxetine (100 µg /kg, iv) on the activity of 5-HT neurons in the dorsal raphe nucleus are reversed when given robazotan hydrochloride (1-100 µg/kg; iv) at 5 µg/kg [1]. The rate at which 5-HT cells discharge is accelerated by intravenous robalzotan hydrochloride (5, 50 µg/kg) [1]. Robalzotan hydrochloride (0.3; 1 and 3 µmol/kg subcutaneously) produces scaffold FC extracellular ACh levels dose-dependent increase [3]. Robalzotan hydrochloride (2-100 µg/kg; iv) modifies 5-HT1A in monkeys in a dose-dependent manner.
Animal Protocol	Animal/Disease Models: 300-600 g, male SD (SD (Sprague-Dawley)) rat (body[2]. 5-HT cells)[1] Doses: 1, 5, 12.5, 25, 50, 100 µg/kg Route of Administration: intravenous (iv) (iv)injection Experimental Results: The activity of such neurons increased Dramatically with increasing robazotane doses of 5-100 µg/kg at 5 µg/kg or 50-400 mg/kg without further affecting the firing rate of 5-HT neurons. Animal/Disease Models: 3-4 kg, cynomolgus monkey[2] Doses: 2, 10, 20, 100 µg/kg Route of Administration: intravenous (iv) (iv)injection Experimental Results: Occupies 5-HT1A receptors in a dose-dependent and saturable manner, and The 5-HT1A receptor occupancy rate (70-80%) is reached after the highest concentration of 100 μg/kg.
References	[1]. Arborelius L, et al. The 5-HT(1A) receptor antagonist robalzotan completely reverses citalopram-induced inhibition of serotonergic cell firing. Eur J Pharmacol. 1999 Oct 8;382(2):133-8. [2]. Farde L, et al. PET-Determination of robalzotan (NAD-299) induced 5-HT(1A) receptor occupancy in the monkey brain. Neuropsychopharmacology. 2000 Apr;22(4):422-9. [3]. Hu, Xiao Jing, et al. Modulation of acetylcholine release by serotonergic 5-HT1A and 5-HT1B receptors : a microdialysis study in the awake rat. 2007.

Solubility Data

Solubility (In Vitro)

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

Solubility (In Vivo)

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 Formulations (e.g. IP/IV/IM/SC) 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). 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 Formulations 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). 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.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.8181 mL	14.0905 mL	28.1809 mL
	5 mM	0.5636 mL	2.8181 mL	5.6362 mL
	10 mM	0.2818 mL	1.4090 mL	2.8181 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.