IDRA-21 is a positive allosteric modulator (PAM) of the AMPA receptor and a benzothiadiazine derivative. It is a chiral molecule, with (+)-IDRA-21 being the active form. IDRA-21 shows nootropic effects in animal studies, significantly improving learning and memory. It is around 10–30 times more potent than aniracetam in reversing cognitive deficits induced by alprazolam or scopolamine, and produces sustained effects lasting for up to 48 hours after a single dose. The mechanism for this action is thought to be through promoting the induction of long-term potentiation between synapses in the brain.

Physicochemical Properties

Molecular Formula	C8H9CLN2O2S
Molecular Weight	232.6873
Exact Mass	232.007
CAS #	22503-72-6
PubChem CID	3688
Appearance	Off-white to yellow solid powder
Density	1.4±0.1 g/cm3
Boiling Point	405.1±55.0 °C at 760 mmHg
Flash Point	198.8±31.5 °C
Vapour Pressure	0.0±0.9 mmHg at 25°C
Index of Refraction	1.572
LogP	0.77
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	0
Heavy Atom Count	14
Complexity	314
Defined Atom Stereocenter Count	0
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

References	Journal of Pharmaceutical Sciences. 1995,84(8): 937–942.
Additional Infomation	7-chloro-3-methyl-3,4-dihydro-2H-1$l^{6},2,4-benzothiadiazine 1,1-dioxide is a benzothiadiazine.

Solubility Data

Solubility (In Vitro)

DMSO : ~250 mg/mL (~1074.39 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (8.94 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 20.8 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: ≥ 2.08 mg/mL (8.94 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 20.8 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. Solubility in Formulation 3: ≥ 2.08 mg/mL (8.94 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	4.2976 mL	21.4878 mL	42.9756 mL
	5 mM	0.8595 mL	4.2976 mL	8.5951 mL
	10 mM	0.4298 mL	2.1488 mL	4.2976 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.