NMDA Receptor

In HEK cells, (-)-Dizocilpine maleate ((-)-MK-801 maleate) dramatically reduced the uptake of all three monoamine transporters (dopamine, serotonin, and norepinephrine) in a dose-dependent manner. On the norepinephrine, dopamine, and serotonin transporters, (-)-Dizocilpine has Ki values of 3.7 μM, 40 μM, and 47 μM, respectively[2].

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(+)-MK-801 is known to be a specific non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors. However, besides having an anticonvulsant effect, this compound possesses a central sympathomimetic effect and an anxiolytic-like action, raising the possibility that (+)-MK-801 might affect monoamine uptake systems. To elucidate this possibility, we investigated the effects of (+)-MK-801 on monoamine transporters expressed in HEK cells. (+)-MK-801 significantly inhibited the uptake of all three monoamine transporters in a dose-dependent manner and the inhibitions were competitive with respect to monoamines. The Ki values of (+)-MK-801 on the norepinephrine, dopamine and serotonin transporters were 3.2 microM, 40 microM and 43 microM, respectively. In addition, (-)-MK-801, a less potent antagonist of NMDA receptors, also inhibited monoamine transporters with a similar potency as that of (+)-MK-801. These results clearly indicate that MK-801, a non-competitive antagonist of NMDA receptors, competitively inhibits monoamine transporters without stereoselectivity [2].

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The compound MK-801 [(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5,10-imine maleate)] is a potent anticonvulsant that is active after oral administration and whose mechanism of action is unknown. We have detected high-affinity (Kd = 37.2 +/- 2.7 nM) binding sites for [3H]MK-801 in rat brain membranes. These sites are heat-labile, stereoselective, and regionally specific, with the hippocampus showing the highest density of sites, followed by cerebral cortex, corpus striatum, and medulla-pons. There was no detectable binding in the cerebellum. MK-801 binding sites exhibited a novel pharmacological profile, since none of the major neurotransmitter candidates were active at these sites. The only compounds that were able to compete for [3H]MK-801 binding sites were substances known to block the responses of excitatory amino acids mediated by the N-methyl-D-aspartate (N-Me-D-Asp) receptor subtype. These comprised the dissociative anesthetics phencyclidine and ketamine and the sigma-type opioid N-allylnormetazocine (SKF 10,047). Neurophysiological studies in vitro, using a rat cortical-slice preparation, demonstrated a potent, selective, and noncompetitive antagonistic action of MK-801 on depolarizing responses to N-Me-D-Asp but not to kainate or quisqualate. The potencies of phencyclidine, ketamine, SKF 10,047, and the enantiomers of MK-801 as N-Me-D-Asp antagonists correlated closely (r = 0.99) with their potencies as inhibitors of [3H]MK-801 binding. This suggests that the MK-801 binding sites are associated with N-Me-D-Asp receptors and provides an explanation for the mechanism of action of MK-801 as an anticonvulsant [3].

In the social defeat stress model, (-)-Dizocilpine maleate (0.1 mg/kg; intraperitoneal injection; male adult C57BL/6 mice) therapy produces fast antidepressant effects[1].

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In animal modeling, dizocilpine maleate can be used to create models of schizophrenia. Recent research suggests that drug-related memories are reactivated after exposure to environmental cues and may undergo reconsolidation, a process that can strengthen memories. Conversely, reconsolidation may be disrupted by certain pharmacological agents such that the drug-associated memory is weakened. Several studies have demonstrated disruption of memory reconsolidation using a drug-induced conditioned place preference (CPP) task, but no studies have explored whether cocaine-associated memories can be similarly disrupted in cocaine self-administering animals after a cocaine priming injection, which powerfully reinstates drug-seeking behavior. Here we used cocaine-induced CPP and cocaine self-administration to investigate whether the N-methyl-D-aspartate receptor antagonist (+)-5methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) given just prior to reactivation sessions would suppress subsequent cocaine-primed reinstatement (disruption of reconsolidation). Systemic injection of MK-801 (0.05 or 0.20 mg/kg administered intraperitoneally) in rats just prior to reactivation of the cocaine-associated memory in the CPP context attenuated subsequent cocaine-primed reinstatement, while no disruption occurred in rats that did not receive reactivation in the CPP context. However, in rats trained to self-administer cocaine, systemic administration of MK-801 just prior to either of two different types of reactivation sessions had no effect on subsequent cocaine-primed reinstatement of lever-pressing behavior. Thus, systemic administration of MK-801 disrupted the reconsolidation of a cocaine-associated memory for CPP but not for self-administration. These findings suggest that cocaine-CPP and self-administration do not use similar neurochemical processes to disrupt reconsolidation or that cocaine-associated memories in self-administering rats do not undergo reconsolidation, as assessed by lever-pressing behavior under cocaine reinstatement conditions [5].

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The effects of five administrations (3- to 4-day intervals) of morphine (MOR: 10 and 20 mg/kg, s.c.) alone, MK-801 (dizocilpine: 0.03, 0.1, 0.3 and 1 mg/kg, i.p.) alone, and combinations of MOR with MK-801 on the ambulation in mice were investigated. MK-801 at 0.3 and 1 mg/kg, but not at 0.03 and 0.1 mg/kg, significantly increased the ambulation of mice. Although the mice given repeated administrations of MK-801 (0.3 and 1 mg/kg) exhibited enhancement and reduction, respectively, in the ambulation-increasing effect of the individual doses, they showed significantly higher sensitivity than the saline-treated mice to the challenge with MOR (10 mg/kg). The repeated administrations of MOR (10 and 20 mg/kg) induced a progressive enhancement of the ambulation-increasing effect. The mice repeatedly given MOR (10 mg/kg) exhibited significant increase in the sensitivity to MK-801 (0.03-0.3 mg/kg). The coadministrations of MOR with MK-801 intensified the ambulation-increasing effect, and repeated coadministrations induced progressive enhancement of the effect, except for the combinations of MOR (10 or 20 mg/kg) with MK-801 (1 mg/kg). However, the induction of MOR sensitization was not modified by any doses of MK-801, except for the case of combination of MOR (20 mg/kg) with MK-801 (1 mg/kg) which was highly toxic (i.e., eliciting death or a moribund condition). On the other hand, simultaneous treatment with SCH 23390 (0.05 mg/kg, s.c.) or nemonapride (0.05 mg/kg, s.c.), or 4-hr pretreatment with reserpine (1 mg/kg, s.c.) strongly, and 4-hr pretreatment with alpha-methyl-p-tyrosine (200 mg/kg, i.p.) partially reduced the ambulation-increasing effect of both MOR (10 mg/kg) and MK-801 (0.3 mg/kg). Simultaneous treatment with naloxone (1 mg/kg, sc) selectively reduced the effect of MOR. However, simultaneous treatment with apomorphine (0.1 mg/kg, s.c.) did not modify the effects of either drug. These results suggest that the characteristics of the ambulation-increasing effects of MOR and MK-801 are similar to each other, and that the repeated treatments with MK-801 induce a cross-sensitization to MOR and vice versa[6].

(+)-MK-801 is known to be a specific non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors. However, besides having an anticonvulsant effect, this compound possesses a central sympathomimetic effect and an anxiolytic-like action, raising the possibility that (+)-MK-801 might affect monoamine uptake systems. To elucidate this possibility, we investigated the effects of (+)-MK-801 on monoamine transporters expressed in HEK cells. (+)-MK-801 significantly inhibited the uptake of all three monoamine transporters in a dose-dependent manner and the inhibitions were competitive with respect to monoamines. The Ki values of (+)-MK-801 on the norepinephrine, dopamine and serotonin transporters were 3.2 microM, 40 microM and 43 microM, respectively. In addition, (-)-MK-801, a less potent antagonist of NMDA receptors, also inhibited monoamine transporters with a similar potency as that of (+)-MK-801. These results clearly indicate that MK-801, a non-competitive antagonist of NMDA receptors, competitively inhibits monoamine transporters without stereoselectivity[2].

Animal/Disease Models: Male adult C57BL/6 mice ( 20-25g ; aged 8 weeks) with social defeat stress model[1]
Doses: 0.1 mg/kg
Route of Administration: intraperitoneal (ip)injection
Experimental Results: Induced rapid antidepressant effects in the social defeat stress model.

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Systemic injection of Dizocilpine/MK-801 (0.05 or 0.20 mg/kg administered intraperitoneally) in rats just prior to reactivation of the cocaine-associated memory in the CPP context attenuated subsequent cocaine-primed reinstatement, while no disruption occurred in rats that did not receive reactivation in the CPP context. However, in rats trained to self-administer cocaine, systemic administration of MK-801 just prior to either of two different types of reactivation sessions had no effect on subsequent cocaine-primed reinstatement of lever-pressing behavior. Thus, systemic administration of MK-801 disrupted the reconsolidation of a cocaine-associated memory for CPP but not for self-administration. These findings suggest that cocaine-CPP and self-administration do not use similar neurochemical processes to disrupt reconsolidation or that cocaine-associated memories in self-administering rats do not undergo reconsolidation, as assessed by lever-pressing behavior under cocaine reinstatement conditions.[5]

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Subjects [5]
Male Sprague-Dawley and Long-Evans Hooded rats weighing 280–350 g at the start of the experiment were housed in a temperature- and humidity-controlled colony room with a 12-h light/dark cycle (lights on at 6:00 a.m.). Sprague-Dawley rats were used for all CPP studies, and our initial self-administration studies used Long-Evans rats because of their higher general activity levels and thus higher initial lever pressing during acquisition of the self-administration task. However, to ensure that there were no strain differences in the effects of Dizocilpine/MK-801 on self-administration behavior, we also used Sprague-Dawley rats to test the effects of the highest dose of MK-801 compared with Saline vehicle in this strain. No significant differences were found for the effects of MK-801, so the data from both strains were pooled. Animals undergoing self-administration were housed in a 12-h reverse light/dark cycle (lights on at 6:00 p.m.). Experiments were conducted according to the National Institutes of Health Guide for the Care and Use of Laboratory Animals, and experimental protocols were approved by the University Animal Care and Use Committee. Animals were housed two per cage for the CPP studies and individually for the self-administration studies. Food and water were provided ad libitum except for when animals were engaged in experiments.

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Drug administration [5]
Dizocilpine(+)-MK-801 hydrogen maleate was dissolved in sterile saline for i.p. injection (1 mL/kg). The doses chosen were 0.05 and 0.20 mg/kg, based on previous work by Przybyslawski and Sara (1997).

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Surgery [5]
Self-administration surgery was conducted according to a modification of McFarland and Kalivas (2001). Rats were anesthetized with zyket (ketamine 87 mg/kg + xylazine 13 mg/kg) given intramuscularly prior to implanting a chronic indwelling i.v. catheter. The catheter was surgically implanted into the right jugular vein, and the distal end was led subcutaneously to the back between the scapulas. Catheters were constructed from Silastic tubing (9 cm; inner diameter 0.025 in, outer diameter 0.047 in) connected to a back-mount cannula pedestal, a bent 22-gauge metal cannula encased within a plastic screw connector attached to a polyester mesh (Plastics One). A small ball of silicone sealant was placed ∼2.8 cm from the end of the catheter. The right jugular vein was isolated, the most anterior portion of the vein was tied shut, and a small incision was made. The distal end of the catheter was inserted into the vein until the silicone ball was flush with the vein. The vein was secured by tying suture thread on both sides of the silicone ball; additionally, the thread on both sides was tied together. Immediately after surgery, the catheter was injected with 0.1 mL of locking solution: heparin (500 U/mL), gentamicin (5 mg/mL), and glycerol (60%) in sterile saline. Incisions were sutured, and the animal was given 5–7 d to recover. After surgery, the catheter was flushed daily with 0.1 mL of heparin (10 U/mL) and gentamicin antibiotic (5 mg/mL) in sterile saline to help protect against infection and catheter occlusion.

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Behavioral procedures [5]
CPP [5]
All CPP studies were conducted during the same time of day. The proposed studies employed a three-compartment CPP apparatus as previously described (Brown et al. 2007). Briefly, the procedure consisted of a preconditioning preference test, training for 8 d (4 saline pairings alternating with 4 cocaine pairings), testing for CPP acquisition followed by extinction sessions, and cocaine-primed reinstatement with a 10 mg/kg, i.p. dose of cocaine (Brown et al. 2007). Except for the training days, rats had access to all three compartments of the CPP apparatus.

In Experiment 1, we tested whether Dizocilpine/MK-801 would impair reconsolidation of the memory for the cocaine-associated context during reinstatement testing. Animals underwent preconditioning, conditioning, testing, and extinction as described above, and on Reactivation Day 1, rats received saline or MK-801 (0.05 mg/kg or 0.20 mg/kg, i.p.) 30 min prior to a cocaine injection (10 mg/kg, i.p.) and placed immediately into the central compartment of the CPP box (Reactivation Day 1). Rats were allowed to explore all three compartments. The next day, the procedure from Reactivation Day 1 was repeated (Reactivation Day 2). This procedure was given for 2 d because our previous studies using a different pharmacological agent (Brown et al. 2007) indicated that one day of memory reactivation was not sufficient to disrupt subsequent cocaine-primed reinstatement. The following day, animals were tested for cocaine-primed reinstatement without any prior injection of either saline or MK-801 before being placed into the CPP box (Reinstatement Day). Rats were allowed to explore all three compartments.

Experiment 2 was identical to Experiment 1 with the exception of the cage location where Dizocilpine/MK-801 and cocaine injection took place on Reactivation Days 1 and 2. In Experiment 2, animals were given saline or MK-801 followed by cocaine 30 min later in the home cage instead of in the CPP apparatus for the two days of “reactivation.” This was done to determine whether reactivation of the memory for the cocaine-associated context by cocaine in the CPP context was necessary for the ability of MK-801 to disrupt reconsolidation. Animals underwent preconditioning, conditioning, testing, and extinction as described above but animals were injected with saline or MK-801 (0.20 mg/kg, i.p.) 30 min prior to a cocaine injection (10 mg/kg, i.p.) in the home cage. Animals remained in the home cages, and the next day, the procedure from the first day of reactivation was repeated. The following day, animals were tested for cocaine-primed reinstatement in their CPP box without any prior microinjection of saline or MK-801, exactly as described for the Reinstatement Day in Experiment 1 above.

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Methods: The antidepressant effects of (+)-MK-801 (0.1mg/kg) and (-)-MK-801 (0.1mg/kg) in the social defeat stress model were examined.[1]
Results: In the tail suspension and forced swimming tests, both stereoisomers significantly attenuated increased immobility time in susceptible mice. In the sucrose preference test, (+)-MK-801, but not (-)-MK-801, significantly enhanced reduced sucrose consumption 2 or 4 days after a single dose. However, no antianhedonia effects were detected 7 days after a single dose of either stereoisomer.[1]
Conclusions: Both stereoisomers of MK-801 induced rapid antidepressant effects in the social defeat stress model, although neither produced a long-lasting effect (7 days).[1]

Dizocilpine (MK-801) is a non-competitive NMDA receptor antagonist with high binding affinity, requiring an open channel for receptor blockade. Key pharmacokinetic characteristics include:
1. Bioavailability & Absorption
o While specific bioavailability data for dizocilpine is not provided in the sources, its structural analog orphenadrine (an NMDA antagonist with similar properties) demonstrates blood-brain barrier penetration, suggesting dizocilpine may share this trait.

2. Metabolism & Elimination
o Studies on reeler mice indicate dizocilpine’s efficacy correlates with GABAergic modulation, implying potential hepatic metabolism involving neurotransmitter pathways.
o Comparative pharmacokinetic data from paliperidone derivatives suggest rapid metabolism may occur for certain CNS-targeting drugs, though dizocilpine’s exact metabolic profile remains unspecified.

3. Pharmacodynamic Interactions
o Dizocilpine’s NMDA receptor blockade is enhanced in models of synaptic plasticity dysfunction, suggesting context-dependent pharmacokinetic-pharmacodynamic relationships.
For precise quantification (e.g., T_max, half-life), additional data beyond the current search results would be required.

[1]. Antidepressant Effects of (+)-MK-801 and (-)-MK-801 in the Social Defeat Stress Model. Int J Neuropsychopharmacol. 2016 Dec 30;19(12).

[2]. MK-801 blocks monoamine transporters expressed in HEK cells. FEBS Lett. 1998 Feb 27;423(3):376-80.

[3]. The anticonvulsant MK-801 is a potent N-Me-D-Asp antagonist. Proc Natl Acad Sci U S A. 1986 Sep;83(18):7104-8.

[4]. Convergent Strategy to Dizocilpine MK-801 and Derivatives. J Org Chem. 2018 Apr 6;83(7):4264-4269.

[5]. The NMDA antagonist MK-801 disrupts reconsolidation of a cocaine-associated memory for conditioned place preference but not for self-administration in rats. Learn Mem. 2008 Dec 2;15(12):857-65.

[6]. Modification by MK-801 (dizocilpine), a noncompetitive NMDA receptor antagonist sensitization: evaluation by ambulation in mice. Nihon Shinkei Seishin Yakurigaku Zasshi. 1996 Feb;16(1):11-8.

[7]. Decrease of growth and differentiation factor 10 contributes to neuropathic pain through N-Me-D-Asp receptor activation. Neuroreport. 2017 May 24;28(8):444-450.

Dizocilpine maleate is a maleate salt obtained by reaction of dizocilpine with one equivalent of maleic acid. It has a role as an anaesthetic, an anticonvulsant, a neuroprotective agent, a nicotinic antagonist and a NMDA receptor antagonist. It is a maleate salt and a tetracyclic antidepressant. It contains a dizocilpine(1+).
A potent noncompetitive antagonist of the NMDA receptor (RECEPTORS, N-METHYL-D-ASPARTATE) used mainly as a research tool. The drug has been considered for the wide variety of neurodegenerative conditions or disorders in which NMDA receptors may play an important role. Its use has been primarily limited to animal and tissue experiments because of its psychotropic effects.

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Background: Current data on antidepressant action of the N-methyl-D-aspartate receptor antagonist, (+)-MK-801, is inconsistent. This study was conducted to examine the effects of (+)-MK-801 and its less potent stereoisomer, (-)-MK-801, in the social defeat stress model of depression. Methods: The antidepressant effects of (+)-MK-801 (0.1mg/kg) and (-)-MK-801 (0.1mg/kg) in the social defeat stress model were examined. Results: In the tail suspension and forced swimming tests, both stereoisomers significantly attenuated increased immobility time in susceptible mice. In the sucrose preference test, (+)-MK-801, but not (-)-MK-801, significantly enhanced reduced sucrose consumption 2 or 4 days after a single dose. However, no antianhedonia effects were detected 7 days after a single dose of either stereoisomer. Conclusions: Both stereoisomers of MK-801 induced rapid antidepressant effects in the social defeat stress model, although neither produced a long-lasting effect (7 days).[1]

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(+)-MK-801 is known to be a specific non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors. However, besides having an anticonvulsant effect, this compound possesses a central sympathomimetic effect and an anxiolytic-like action, raising the possibility that (+)-MK-801 might affect monoamine uptake systems. To elucidate this possibility, we investigated the effects of (+)-MK-801 on monoamine transporters expressed in HEK cells. (+)-MK-801 significantly inhibited the uptake of all three monoamine transporters in a dose-dependent manner and the inhibitions were competitive with respect to monoamines. The Ki values of (+)-MK-801 on the norepinephrine, dopamine and serotonin transporters were 3.2 microM, 40 microM and 43 microM, respectively. In addition, (-)-MK-801, a less potent antagonist of NMDA receptors, also inhibited monoamine transporters with a similar potency as that of (+)-MK-801. These results clearly indicate that MK-801, a non-competitive antagonist of NMDA receptors, competitively inhibits monoamine transporters without stereoselectivity.[2]

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In summary, our work shows for the first time that the same reactivation parameters and pharmacological agent (MK-801) that disrupted the reconsolidation of a cocaine-associated memory for a CPP task did not disrupt reconsolidation of the memory for a self-administration task. Further, reactivation parameters that mimicked the self-administration procedure itself, and therefore should have promoted robust retrieval of the cocaine-associated memory, also failed to render this memory labile for disruption by MK-801. The possibility of diminishing persistent and unwanted memories by disrupting the reconsolidation process opens exciting new frontiers for developing treatments for pathological disorders, including drug abuse. However, the complexity of memory storage and subsequent memory retrieval that ultimately may lead to memory recoding has only begun to be elucidated and therefore requires further systematic investigation with regard to the timing and the specific parameters used for reactivation.[5]

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Neuropathic pain is a chronic disease with hallmarks such as chronic allodynia and hyperalgesia. Previous studies have shown that the transforming growth factor-β superfamily acts as a protecting factor against neuropathic pain. In the current study, we found that growth and differentiation factor 10 (GDF10), which belongs to the transforming growth factor-β superfamily, is mainly expressed in the superficial layers of spinal dorsal horn neurons and it was dramatically downregulated after spinal nerve ligation and N-methyl-D-aspartate (NMDA) intrathecal infusion. Moreover, the decrease in GDF10 expression and increase in mechanical sensitivity could be blocked by MK-801, an antagonist of the NMDA receptor. These results suggest that the decreasing GDF10 may contribute toward neuropathic pain by facilitating NMDA receptor activation. Our findings shed new light on the understanding of the molecular mechanisms underlying neuropathic pain.[7]

C20H19NO4

337.37

337.131

C, 71.20; H, 5.68; N, 4.15; O, 18.97

121917-57-5

Dizocilpine maleate;77086-22-7;Dizocilpine;77086-21-6

16219612

Typically exists as White to off-white solids at room temperature

320.3ºC at 760 mmHg

152.6ºC

0.000321mmHg at 25°C

3.191

3

5

2

25

432

2

C[C@@]1(N2)C3=CC=CC=C3C[C@H]2C4=CC=CC=C14.O=C(O)/C=C\C(O)=O

QLTXKCWMEZIHBJ-FWHYOZOBSA-N

InChI=1S/C16H15N.C4H4O4/c1-16-13-8-4-2-6-11(13)10-15(17-16)12-7-3-5-9-14(12)16;5-3(6)1-2-4(7)8/h2-9,15,17H,10H2,1H3;1-2H,(H,5,6)(H,7,8)/b;2-1-/t15-,16+;/m0./s1

(Z)-but-2-enedioic acid;(1R,9S)-1-methyl-16-azatetracyclo[7.6.1.02,7.010,15]hexadeca-2,4,6,10,12,14-hexaene

2934.99.9001

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.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.41 mM) (saturation unknown) in 10% EtOH + 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 25.0 mg/mL clear EtOH 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.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.41 mM) (saturation unknown) in 10% EtOH + 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 25.0 mg/mL clear EtOH 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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (7.41 mM) (saturation unknown) in 10% EtOH + 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 25.0 mg/mL clear EtOH stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: ≥ 2.08 mg/mL (6.17 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 of PEG300 and mix evenly; then add 50 μL of Tween-80 to the above solution and mix evenly; then add 450 μL of 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.

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Solubility in Formulation 5: ≥ 2.08 mg/mL (6.17 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.

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Solubility in Formulation 6: ≥ 2.08 mg/mL (6.17 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.

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Solubility in Formulation 7: 30% PEG400+0.5% Tween80+5% propylene glycol:15 mg/mL

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Solubility in Formulation 8: 4.55 mg/mL (13.49 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication (<60°C).

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 (Please use freshly prepared in vivo formulations for optimal results.)