ORL-1 (opioid receptor like -1); mu opioid receptor; hNOP receptor (EC50 = 13 nM); hMOP receptor (EC50 = 1.2 nM); hKOP receptor (EC50 = 17 nM); hDOP receptor (EC50 = 110 nM)

With Ki values of 1±0.5 nM, 2.4±1.2 nM, and 64±11 nM for rat NOP, mu-opioid peptide (MOP) receptor, and kappa-opioid peptide (KOP) receptor, and 0.9±0.2 nM, 0.7±0.3 nM, and 2.6±1.4 nM for rat NOP, MOP, and KOP receptor, respectively, cebranopadol binds to opioid receptors with high affinity (subnanomolar to nanomolar range) to nociceptin/orphanin FQ peptide (NOP) and opioid receptors[1].

With ED50 values of 0.5-5.6 μg/kg after intravenous and 25.1 μg/kg after oral administration, cebrachanopadol demonstrates highly potent and efficacious antinociceptive and antihypersensitive effects in several rat models of acute and chronic pain (tail-flick, rheumatoid arthritis, bone cancer, spinal nerve ligation, and diabetic neuropathy). Cebranopadol is more effective in models of chronic neuropathic pain than acute nociceptive pain when compared to selective MOP receptor agonists. The long half-life of cebranopadol is demonstrated by its prolonged duration of action (up to 7 hours after intravenous 12 μg/kg; >9 hours after oral 55 μg/kg in the rat tail-flick test). Pretreatment with either opioid receptor antagonist naloxone or selective NOP receptor antagonist J-113397 partially reverses the antihypersensitive activity of cebranopadol in the spinal nerve ligation model, suggesting that both opioid receptor agonism and NOP are involved in this activity[1].

Cebranopadol (trans-6'-fluoro-4',9'-dihydro-N,N-dimethyl-4-phenyl-spiro[cyclohexane-1,1'(3'H)-pyrano[3,4-b]indol]-4-amine) is a novel analgesic nociceptin/orphanin FQ peptide (NOP) and opioid receptor agonist [Ki (nM)/EC50 (nM)/relative efficacy (%): human NOP receptor 0.9/13.0/89; human mu-opioid peptide (MOP) receptor 0.7/1.2/104; human kappa-opioid peptide receptor 2.6/17/67; human delta-opioid peptide receptor 18/110/105].[1]

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Human MOP, DOP, KOP, and NOP receptor binding assays were run in microtiter plates with wheat germ agglutinin-coated scintillation proximity assay beads. [N-allyl-2,3-3H]naloxone and [tyrosyl-3,5-3H]deltorphin II, [3H]Ci-977, and [leucyl-3H]nociceptin were used as ligands for the MOP, DOP, KOP, and NOP receptor binding studies, respectively. The KD values of the radioligands used for the calculation of Ki values were provided as supplemental information. The assay buffer used for the MOP, DOP, and KOP receptor binding studies was 50 mM Tris-HCl (pH 7.4) supplemented with 0.052 mg/mL bovine serum albumin. For the NOP receptor binding studies, the assay buffer used was 50 mM HEPES, 10 mM MgCl2, 1 mM EDTA (pH 7.4). The final assay volume of 250 μL/well included 1 nM [3H]naloxone, 1 nM [3H]deltorphin II, 1 nM [3H]Ci-977, or 0.5 nM [3H]nociceptin as a ligand and cebranopadol in dilution series. Cebranopadol was diluted with 25% DMSO in water to yield a final 0.5% DMSO concentration, which also served as a respective vehicle control. Assays were started by the addition of beads (1 mg beads/well), which had been preloaded for 15 minutes at room temperature with 23.4 μg of human MOP membranes, 12.5 μg of human DOP membrane, 45 μg of human KOP membranes, or 25.4 µg of human NOP membranes per 250 µL of final assay volume. After short mixing, the assays were run for 90 minutes at room temperature. The microtiter plates were then centrifuged for 20 minutes at 500 rpm, and the signal rate was measured by means of a 1450 MicroBeta Trilux. IC50 values reflecting 50% displacement of [3H]naloxone-, [3H]deltorphin II-, [3H]Ci-977-, or [3H]nociceptin-specific receptor binding were calculated by nonlinear regression analysis. Individual experiments were run in duplicate and were repeated three times in independent experiments[1].

Cebranopadol was tested for its agonistic activity on human recombinant MOP, DOP, or NOP receptor-expressing cell membranes from Chinese hamster ovary K1 cells, or KOP receptor-expressing cell membranes from human embryonic kidney cell line 293 cells. For each assay, 10 µg of membrane proteins was incubated for 45 minutes at 25°C with 0.4 nM [35S]GTPγS (GE Healthcare) and various concentrations of agonists in a buffer containing 20 mM HEPES (pH 7.4), 100 mM NaCl, 10 mM MgCl2, 1 mM EDTA, 1 mM dithiothreitol, 1.28 mM NaN3, and 10 µM guanosine diphosphate. The bound radioactivity was calculated using the methods previously mentioned.

Cebranopadol was dissolved in vehicle that consisted of 5% dimethylsulfoxide, 5% Emulphor, and 90% distilled water. The solution was vortexed before filling a 1-ml syringe for oral injection. Cebranopadol was injected orally by gavage at doses of 0.0, 25, and 50 μg/kg. Cocaine HCl was dissolved in 0.9% saline at a dose of 0.5 mg/kg/infusion and self-administered intravenously. Sweetened condensed milk was diluted 2:1 (v/v) in water.[2]

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Effect of Cebranopadol on the Escalation of Cocaine Self-Administration[2]
Rats (n = 14) were trained to self-administer cocaine under a fixed-ratio 1 (FR1) schedule of reinforcement in daily 6-hour sessions. Each active lever press resulted in the delivery of one cocaine dose (0.5 mg/kg/0.1 ml infusion). A 20-second timeout (TO) period followed each cocaine infusion. During the timeout period, responses on the active lever did not have scheduled consequences. This TO period occurred concurrently with illumination of a cue light that was located above the active lever to signal delivery of the positive reinforcement. The rats were trained to self-administer cocaine in 15 sessions (5 days/week) until a stable baseline of reinforcement was achieved (<10% variation over the last three sessions). A within-subjects Latin-square design was used for the drug treatments. The rats were orally injected with cebranopadol (0, 25, and 50 μg/kg) 30 minutes before beginning the sessions. Oral administration was performed by gavage using a 19-gauge needle and 8 cm of Tygon tubing (0.030 inch inner diameter, 0.090 inch outer diameter). The animals were subjected to cocaine self-administration at 2-day intervals between drug tests.

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Effect of Cebranopadol on Sweetened Condensed Milk Self-Administration[2]
Rats (n = 12) were trained to self-administer SCM under an FR1 schedule of reinforcement for 6 hours per day to match cocaine self-administration. After each SCM reward delivery, a 20-second TO period occurred, during which responses on the active lever had no scheduled consequences. This TO period occurred concurrently with illumination of a cue light that was located above the active lever to signal delivery of the positive reinforcement. The rats were trained to self-administer SCM for several days until a stable baseline of reinforcement was achieved (<10% variation over the last three sessions). When the stable baseline was reached, the rats orally received cebranopadol (0, 25, and 50 μg/kg) 30 minutes before beginning the next session. The animals were subjected to SCM self-administration at 2-day intervals between drug tests.

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Cebranopadol-Induced Conditioned Place Preference and Locomotor Activity[2]
Cebranopadol-induced CPP was evaluated using a biased, counterbalanced CPP procedure. Naive rats (n = 9) were handled and habituated to oral administration for 1 week before beginning the study. The experiment consisted of three 30-minute phases: pretest (one session), conditioning (eight sessions), and preference test (one session). The rats were placed in a dim (40 lux) room 30 minutes before starting the tests. A two-chambered (38 cm × 32 cm × 32 cm) place conditioning apparatus was used, with visual cues on the walls (stripes or dots for compartments A and B, respectively) and tactile cues on the floor (smooth or rough for compartments A and B, respectively). On day 1 (pretest), naive rats were placed between the two chambers and allowed to freely explore both chambers for 30 minutes. Individual bias toward either compartment A or B was observed, and the animals were assigned to place conditioning subgroups according to their least-preferred compartment; therefore, biased assignment was used. Conditioning was performed within subjects. Each rat received cebranopadol (25 μg/kg orally) and vehicle on alternating days in a counterbalanced design 30 minutes before being placed in the conditioning chamber. The preference test was performed 24 hours after the last conditioning session. Thirty minutes after vehicle administration, the rats were placed in the nonconditioned side of the apparatus with free access to both chambers. The time spent in the different chambers was recorded. Locomotor activity was recorded in each phase (pretest, conditioning, and preference test) using a video camera that was connected to the ANY-maze Video Tracking System 5.11.

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Effect of Cebranopadol on Conditioned Reinstatement of Cocaine-seeking Behavior[2]
Cocaine Self-Administration Training.[2]
Rats (n = 10) were surgically prepared with indwelling microurethane catheters that were inserted in the right jugular vein. After 7 days of postsurgical recovery, the rats began self-administration training. The rats were trained to self-administer cocaine (0.5 mg/kg/0.1 ml infusion, i.v.) for 6 hours/day on an FR1 schedule in the presence of a contextual/discriminative stimulus (SD). Each session was initiated by extending two retractable levers into the operant conditioning chamber. Constant 70-dB white noise served as a discriminative stimulus that signaled availability of the reinforcer throughout the session. Responses on the right, active lever were reinforced with a dose of cocaine, followed by a 20-second TO period that was signaled by illumination of a cue light above the active lever. During this TO period, the lever remained inactive to prevent accidental overdosing with cocaine. Responses on the left, inactive lever had no scheduled consequences.

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Conditioned Reinstatement.[2]
Two days later, the rats were presented with the SD. To evaluate the effect of cebranopadol on the conditioned reinstatement of cocaine seeking, the rats were treated with cebranopadol (0, 25, and 50 μg/kg) in a counterbalanced Latin-square design 30 minutes before the reinstatement test. The reinstatement test lasted 2 hours under SD conditions, except that cocaine was unavailable. Cebranopadol was administered only in the SD conditions, with a 2-day interval between tests.

8.9 and 26.6 mg/kg s.c. for whole-body plethysmography test in conscious rats.

Sprague-Dawley rats

[1]. Cebranopadol: a novel potent analgesic nociceptin/orphanin FQ peptide and opioid receptor agonist. J Pharmacol Exp Ther. 2014 Jun;349(3):535-48.

[2]. Cebranopadol Blocks the Escalation of Cocaine Intake and Conditioned Reinstatement of Cocaine Seeking in Rats. J Pharmacol Exp Ther. 2017 Sep;362(3):378-384.

[3]. Evaluation of cebranopadol, a dually acting nociceptin/orphanin FQ and opioid receptor agonist in mouse models of acute, tonic, and chemotherapy-induced neuropathic pain. Inflammopharmacology. 2017 Oct 25.

Cebranopadol is a member of indoles.
Cebranopadol has been used in trials studying the treatment of Pain, Neoplasms, and Chronic Pain.
Cebranopadol is an orally available benzenoid that acts as an opioid peptide receptor agonist for the nociceptin/orphanin FQ peptide receptor (opioid receptor like -1; OPRL1; ORL-1; NOP; kappa-type 3 opioid receptor) and the classical opioid receptors, mu, delta and kappa, with potential anti-nociceptive activity. Upon oral administration, cebranopadol binds to NOP and the mu, delta and kappa opioid receptors, which enhances NOP- and opioid receptor-mediated signaling, interferes with the sensation of pain and results in an analgesic effect. NOP, a member of the opioid receptor family, and its endogenous ligand nociceptin play key roles in the regulation of various brain activities including pain, and some inflammatory and immune responses.

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Drug Indication
Treatment of chronic pain.

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Cebranopadol (trans-6'-fluoro-4',9'-dihydro-N,N-dimethyl-4-phenyl-spiro[cyclohexane-1,1'(3'H)-pyrano[3,4-b]indol]-4-amine) is a novel analgesic nociceptin/orphanin FQ peptide (NOP) and opioid receptor agonist [Ki (nM)/EC50 (nM)/relative efficacy (%): human NOP receptor 0.9/13.0/89; human mu-opioid peptide (MOP) receptor 0.7/1.2/104; human kappa-opioid peptide receptor 2.6/17/67; human delta-opioid peptide receptor 18/110/105]. Cebranopadol exhibits highly potent and efficacious antinociceptive and antihypersensitive effects in several rat models of acute and chronic pain (tail-flick, rheumatoid arthritis, bone cancer, spinal nerve ligation, diabetic neuropathy) with ED50 values of 0.5-5.6 µg/kg after intravenous and 25.1 µg/kg after oral administration. In comparison with selective MOP receptor agonists, cebranopadol was more potent in models of chronic neuropathic than acute nociceptive pain. Cebranopadol's duration of action is long (up to 7 hours after intravenous 12 µg/kg; >9 hours after oral 55 µg/kg in the rat tail-flick test). The antihypersensitive activity of cebranopadol in the spinal nerve ligation model was partially reversed by pretreatment with the selective NOP receptor antagonist J-113397[1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one] or the opioid receptor antagonist naloxone, indicating that both NOP and opioid receptor agonism are involved in this activity. Development of analgesic tolerance in the chronic constriction injury model was clearly delayed compared with that from an equianalgesic dose of morphine (complete tolerance on day 26 versus day 11, respectively). Unlike morphine, cebranopadol did not disrupt motor coordination and respiration at doses within and exceeding the analgesic dose range. Cebranopadol, by its combination of agonism at NOP and opioid receptors, affords highly potent and efficacious analgesia in various pain models with a favorable side effect profile.[1]

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Cebranopadol is a novel agonist of nociceptin/orphanin FQ peptide (NOP) and opioid receptors with analgesic properties that is being evaluated in clinical Phase 2 and Phase 3 trials for the treatment of chronic and acute pain. Recent evidence indicates that the combination of opioid and NOP receptor agonism may be a new treatment strategy for cocaine addiction. We sought to extend these findings by examining the effects of cebranopadol on cocaine self-administration (0.5 mg/kg/infusion) and cocaine conditioned reinstatement in rats with extended access to cocaine. Oral administration of cebranopadol (0, 25, and 50 μg/kg) reversed the escalation of cocaine self-administration in rats that were given extended (6 hour) access to cocaine, whereas it did not affect the self-administration of sweetened condensed milk (SCM). Cebranopadol induced conditioned place preference but did not affect locomotor activity during the conditioning sessions. Finally, cebranopadol blocked the conditioned reinstatement of cocaine seeking. These results show that oral cebranopadol treatment prevented addiction-like behaviors (i.e., the escalation of intake and reinstatement), suggesting that it may be a novel strategy for the treatment of cocaine use disorder. However, the conditioned place preference that was observed after cebranopadol administration suggests that this compound may have some intrinsic rewarding effects.[2]

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One limitation of the present study was the lack of full characterization of the pharmacokinetics and pharmacodynamics of cebranopadol. We also did not evaluate the effects of cebranopadol on the pharmacokinetics of cocaine. However, we do not believe that the reduction of cocaine escalation was related to possible pharmacokinetic effects on blood cocaine levels because cebranopadol effectively reduced conditioned reinstatement. In this case, cocaine was unavailable, thus excluding possible effects on blood cocaine levels. We also did not identify shifts in the dose-response curve or specific receptors that mediate its preclinical efficacy. Follow-up studies are needed to fully characterize the reinforcing properties and possible abuse potential of cebranopadol, particularly considering that we found that cebranopadol produced conditioned place preference. However, although such characterization studies are important from a theoretical perspective to understand the precise mechanisms of action and facilitate medication development, cebranopadol has already been shown to be well tolerated in humans and is already being tested in several clinical trials for the treatment of pain. In summary, the present study provides preclinical evidence of the efficacy of cebranopadol in reversing compulsive-like responding for cocaine and cue-induced reinstatement of cocaine seeking. Cebranopadol may be a new therapeutic option for the prevention of cocaine abuse and relapse.[2]

C24H27FN2O

378.49

378.21

C, 68.34; H, 6.58; F, 4.00; N, 5.90; O, 15.17

863513-91-1

Cebranopadol ((1α,4α)stereoisomer);863513-93-3

11848225

Light yellow to yellow solid powder

1.2±0.1 g/cm3

547.5±50.0 °C at 760 mmHg

284.9±30.1 °C

0.0±1.5 mmHg at 25°C

1.644

5.14

1

3

2

28

553

0

CSMVOZKEWSOFER-UHFFFAOYSA-N

InChI=1S/C24H27FN2O/c1-27(2)23(17-6-4-3-5-7-17)11-13-24(14-12-23)22-19(10-15-28-24)20-16-18(25)8-9-21(20)26-22/h3-9,16,26H,10-15H2,1-2H3

6-fluoro-N,N-dimethyl-1'-phenylspiro[4,9-dihydro-3H-pyrano[3,4-b]indole-1,4'-cyclohexane]-1'-amine

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

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: 0.67 mg/mL (1.77 mM) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 6.7 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.

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Solubility in Formulation 2: 0.67 mg/mL (1.77 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 6.7 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 3: ≥ 0.67 mg/mL (1.77 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 6.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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