Analgesic substance of endogenous origin, pharmaceutical composition based thereon and methods for using same

Abstract

The claimed solution relates to pharmaceuticals, cosmeceuticals, medicine and veterinary medicine and can be used for producing an effective and safe analgesic for the treatment of pain of different origins, thereby providing relief for acute and chronic pain. The solution is directed toward the development of radically new analgesics of endogenous origin capable of rivaling opiates and opioids in a variety of indices. The essence of the solution consists in a technology for the creation of an analgesic substance that is a chelate complex of general formula CTS-M2+, where CTS is a molecule of a cardiotonic steroid, and М2+ is any doubly charged inorganic cation. In a specific embodiment, the substance is a calcium chelate complex of a molecule of ouabain. Proposed are methods for administering a pharmaceutical composition based on the claimed analgesic substance, which is provided in an injectable form or in the form of a cream, ointment, gel or the like.

Description

[0001] An analgesic substance of endogenous origin, a pharmaceutical composition based on it and methods of their use

[0002] PURPOSE AND SCOPE OF APPLICATION

[0003] The claimed solution relates to pharmaceuticals, cosmeceuticals, medicine and veterinary science and can be used to produce an analgesic for the treatment of pain syndromes of various etiologies, which contributes to the cure of chronic pain.

[0004] PRIOR ART

[0005] Analgesics, or analgesics (from the Greek algos - pain and ap - without), are drugs that have the specific ability to reduce or eliminate the feeling of pain [Mashkovsky M.D. Drugs. 14th edition. Moscow: Novaya Volna, 2003. Vol. 1. P. 145].

[0006] Analgesic (pain-relieving) effects can be exerted not only by analgesics themselves, but also by other substances belonging to different pharmacological groups. For example, drugs used for general anesthesia can have an analgesic effect, and some of them, in appropriate concentrations and doses (for example, trichloroethylene, nitrous oxide), are used specifically for analgesia.

[0007] Local anesthetics also act as analgesics, particularly for peripheral pain. Due to their resorptive effect, local anesthetics can affect the central nervous system, resulting in anxiety, tremors, and seizures. At higher doses, they negatively affect the respiratory and vasomotor centers. Local anesthetics, by blocking voltage-sensitive sodium channels, inhibit myocardial contractility, dilate blood vessels, depress sympathetic innervation, and lower blood pressure. The most important property of local anesthetics is their ability to block nociceptors and other sensory nerve fibers. Therefore, they are used for local anesthesia, particularly during surgery.

[0008] Properly defined, analgesics are agents whose dominant effect is analgesia, which, at therapeutic doses, does not result in loss of consciousness or significant impairment of motor and sensory functions. Excipients, such as sodium bicarbonate, can influence the analgesic effect of a drug and stabilize its dosage form. The World Health Organization (WHO) has endorsed a three-step approach to cancer pain management, which is currently widely used. This involves the use of oral analgesics on a timed basis, depending on the duration of action. In the first step, non-opioid analgesics, such as paracetamol (acetaminophen) and nonsteroidal anti-inflammatory drugs (NSAIDs), are used. If the effect is insufficient, weak opioids, such as codeine, dextropropoxyphene, or tramadol, are added (step two).If this does not relieve the pain, then in the final, third stage, the weak opioid is replaced with a strong one similar to morphine (for example, morphine, hydromorphone, oxycodone or fentanyl).

[0009] This "WHO pain management ladder" has been used since 1986. This approach was later extended to non-cancer pain, including the treatment of chronic pain of various etiologies and locations. Adjunctive medications are used to reduce anxiety and other negative side effects.

[0010] According to their chemical nature, character and mechanisms of pharmacological activity, modern analgesics are divided into two groups.

[0011] The main representatives of analgesics of the first group are derivatives of salicylic acid (sodium salicylate, acetylsalicylic acid, salicylamide, etc.), derivatives of pyrazolone - antipyrine, amidopyrine, analgin, derivatives of para-aminophenol (or aniline) - phenacetin, paracetamol [ibid. P. 146]. These analgesics are synthetic drugs. The analgesic activity of drugs belonging to the first group is manifested in certain types of pain, mainly in neuralgic, muscle, joint pain, headache and toothache. In case of severe pain associated with injuries, abdominal surgeries, etc., they are practically ineffective. These drugs exhibit an antipyretic effect in febrile conditions and an anti-inflammatory effect, expressed to varying degrees in different analgesics of this group.These analgesics do not depress the respiratory and cough centers, nor do they produce euphoria or psychological or physical dependence. The mechanism of action of first-group analgesics involves an effect on the thalamic centers, which inhibits the transmission of pain impulses to the cerebral cortex. Salicylates also inhibit prostaglandin biosynthesis and stimulate the pituitary-adrenal axis, promoting the release of corticosteroids. Their effect on the kinin system is also crucial to the action of first-group analgesics. However, long-term use of these analgesics leads to severe adverse side effects and prolonged pain, necessitating the use of second-group analgesics.

[0012] Analgesics of the second group (also called major analgesics) include natural compounds - morphine and related alkaloids (opiates), and synthetic compounds with opiate-like properties (opioids). They are characterized by strong analgesic activity, which allows their use in trauma (surgery, wounds, etc.) and in diseases accompanied by severe pain (malignant neoplasms, myocardial infarction, narcotic withdrawal, etc.). Based on their sources and chemical structure, analgesics of the second group include natural alkaloids - morphine and codeine, contained in the sleeping poppy; semi-synthetic compounds obtained by chemical modification of the morphine molecule (ethylmorphine); synthetic compounds (promedol, fentanyl, pentazocine, nalbuphine, butorphanol, tramadol, etc.). Most synthetic drugs are obtained by reproducing the simplified structure of morphine.To reduce side effects, atropine, metacin, or other anticholinergics are often prescribed along with morphine [ibid., p. 145]. These drugs have a unique effect on the human central nervous system, resulting in euphoria and the development of psychological and physical dependence (drug addiction) with repeated use, limiting the long-term use of these medications. Patients with established physical dependence may experience a painful withdrawal syndrome when they are deprived of their analgesic medication. Analgesics of the second group cause acute toxic effects, such as respiratory depression and cardiac dysfunction. To alleviate these effects, specialized medications—antagonists—are used, such as naloxone or naltrexone, obtained by chemical modification of the morphine molecule.With repeated use of major analgesics, tolerance typically develops, which is a weakening of the effect of the current prescribed dose of the drug, requiring increasingly higher doses to achieve the analgesic effect. The action of these analgesics is not limited to pain relief. To varying degrees, they have a hypnotic effect, depress respiration and the cough reflex, increase intestinal and bladder tone, and can cause nausea, diarrhea, and other side effects. Due to their pronounced narcotic potential, analgesics of the second group must be stored, prescribed, and dispensed from pharmacies according to special regulations. In recent years, a number of previously used major analgesics with pronounced narcotic potential (tecadine, hydrocodone phosphate, phenadone, and some finished dosage forms containing opium and codeine) have been excluded from the nomenclature of drugs in the Russian Federation [ibid. P. 145].Neurophysiological studies indicate that these analgesics suppress thalamic pain centers and block the transmission of pain impulses to the cerebral cortex. However, their action differs from that of the first group of analgesics, as they affect the central nervous system's ability to summarize subthreshold impulses.

[0013] It is known that specific opiate receptors are present in the brain and other organs [ibid. P. 146]. Their endogenous ligands, that is, physiologically active compounds formed in the body that specifically bind to these receptors, are neuropeptides - primarily enkephalins, endorphins and endomorphins discovered in the USA by Professor D. Zadina [Zadina JE, Hackler L., Ge L., Kastin A. A potent and selective endogenous agonist for the c-opiate receptor / / Nature 1997, V.386. P.499-502]. Endogenous ligands have an analgesic effect and their effect is blocked by specific opiate antagonists. The exogenous analgesic morphine (as well as other opiates and opioids similar in structure) when introduced into the body interacts with the same receptors that are designed to bind endogenous ligands.In addition, it is possible that the action of exogenous analgesics is also associated with the stabilization of endogenous ligands by inactivating enkephalin-destroying enzymes - enkephalinases.

[0014] Opiate receptors have been shown to exist in different subsets (subgroups): μ (mu) (or OP3 according to the IUPHAR system), k (kappa) (OP2), σ (sigma), and δ (delta) (OP1), each with varying functional significance. Mu receptors are believed to mediate supraspinal analgesia, euphoria, respiratory depression, and physical dependence, while kappa receptors mediate spinal analgesia, miosis, and sedation. Different endogenous ligands and major analgesics may bind preferentially to one or another receptor subgroup, which may determine the characteristics of their pharmacological action.

[0015] Various major analgesics also differ in the nature of their binding to opiate receptors. Some of them (morphine, promedol, fentanyl, etc.) are

[0016] "Pure" full agonists; by binding to receptors, they exert the physiological (pharmacological) effect characteristic of endogenous ligands. Others are "pure" antagonists (naloxone, naltrexone). By binding to receptors, they block the action of both endogenous ligands and exogenous opiates. And finally, drugs with a mixed type of action (agonist-antagonists) bind differently to different subgroups of opiate receptors and, therefore, exert an agonistic effect in some types of action, and an antagonistic effect in others (tramadol, nalorphine, pentazocine, nalbuphine, etc.). The effect of major analgesics on peripheral organs (intestines, etc.) is also associated with interaction with the opiate receptors localized there.

[0017] Most opiates do not exhibit a pronounced local anesthetic effect. However, in recent years, they have been found to have a strong analgesic effect when administered epidurally and subarachnoidally. This effect is due to a direct effect on the spinal cord neuronal systems involved in generating nociceptive impulses. This route of opiate administration is used to relieve severe acute and chronic pain.

[0018] From the above, it follows that, according to modern views on the mechanism of action of major analgesics, agonists are the most effective. However, due to the side effects they cause, primarily severe drug dependence (essentially narcotic dependence) and intoxication, their use is strictly limited.

[0019] Tramadol, a latest-generation synthetic analgesic belonging to the group of opiate receptor agonists-antagonists, is ±-trans-2-[(dimethylamino)methyl]-1-(p / -methoxyphenyl)cyclohexanol hydrochloride [ibid. P. 157]. The drug has high analgesic activity and produces a rapid and long-lasting effect. Tramadol is relatively well tolerated, does not cause significant respiratory depression in normal doses, and does not significantly affect blood circulation or the gastrointestinal tract. Tramadol, however, can cause nausea, vomiting, dizziness, and sweating; high blood pressure may decrease slightly.

[0020] A disadvantage of this drug is that tramadol is not a "pure" agonist. Tramadol is less active than morphine and is therefore used in higher doses. Like morphine, repeated use can cause addiction and toxicity in most patients.

[0021] When developing fundamentally new, safe analgesics that lack the numerous negative side effects mentioned above and are capable of replacing opiates, attention should be paid to endogenous substances capable of creating a third group of analgesics that is fundamentally new in its chemical nature, nature, and mechanisms of pharmacological activity. This typically involves the use of peptide-based compounds.

[0022] The prior art includes compounds of endogenous peptide origin that are potentially useful as analgesics. Patent RU2286169 (priority date April 18, 2005, publication date October 27, 2006), "A Family of Peptides Possessing Analgesic Activity," pertains to the pharmaceutical industry and describes the production of peptides of the following formula for the creation of new drugs:

[0023] A-B-Tyr-Pro- (DPro, dHPro, DdPro, DLdHPro, Hyp,) - B-X, where A is O, -Ala, -Asp, -Glu, -Phe, -Gly, -His, -He, -Lys, -Leu, -Met, -Pro, -Arg, -Ser, -Thr, -Vai, -Trp, -Tyr; B is O, -Ala, -Asp, -Glu, -Phe, -Gly, -His, -lie, -Lys, -Leu, -Met, -Pro, -Arg, -Ser, -Thr, -Vai, -Trp, -Tyr; B -O, -Ala, -Asp, -Glu, -Phe, -Gly, -His, -lie, -Lys, -Leu, -Met, -Pro, -Arg, -Ser, -Thr, -Vai, -Trp, -Tyr; X - OH, -OCH3, -MH2.

[0024] According to the authors of this patent, all of the numerous peptides described in it have increased activity compared to pentalgin, analgin, and morphine.

[0025] However, unlike our approach, the materials of this patent do not present the molecular mechanism of binding of these substances to their specific target—the membrane receptor. This is most likely due to the following: since the reference drug was morphine, the analgesic effect of these peptide agents is due to their action on one class of opioid receptors, which are also endogenously activated by other endogenous peptide substances—for example, enkephalins and endorphins. Exogenous use of the latter to replace opiates in clinical practice remains impossible to date, as their use cannot be completely safe: all opioid receptor agonists, as noted above, cause a large number of negative side effects in the human body.

[0026] It should be noted that the description of the invention protected by patent RU2286169 lacks data demonstrating the safety of long-term use of the peptide-based agents in question for the treatment of chronic pain. Data on their effects on the human body are also completely absent. No evidence is provided to demonstrate the absence of adverse side effects such as addiction and toxicity in humans following the use of the aforementioned peptide substances. Since the publication of patent RU2286169, no data has appeared in the global literature demonstrating that a fundamentally new, safe, and effective analgesic capable of replacing opiates and opioids has been developed using even one of the hundreds of short peptides mentioned in this patent. We believe there are several explanations for this.Animal data, particularly when using peptide substances, may differ significantly from the results of clinical studies due to the fact that the efficiency of the mechanisms by which peptidases destroy exogenously applied peptide molecules varies significantly between rodents and humans. In the latter case, the active peptide substance apparently is not effectively delivered to its molecular target in the membrane of the nociceptive neuron in the human nervous system.

[0027] We believe that the substances described in patent RU2286169 can be accepted as a prototype of our invention due to their endogenous (peptide) nature and the attempt of the authors of the cited patent to use them for their intended purpose as analgesics.

[0028] Chronic pain affects over 20% of people worldwide, and this number is constantly growing. Therefore, the main challenge that requires a solution is to control the mechanisms that transform "pain as a symptom," which serves a protective function, into "pain as a disease." Approximately 3.5 million cancer patients suffer daily from pain of varying intensity, and approximately 40% of patients with intermediate-stage cancer and 60-90% with advanced disease experience pain ranging from moderate to severe. The use of narcotic medications in these cases is associated with serious risks due to the many side effects of opiates, including life-threatening central nervous system depression with respiratory depression and even cessation. The significance of this invention may be primarily realized in the development of new approaches to the treatment of chronic pain requiring long-term use of analgesic medications.Chronic pain is defined as "pain that persists beyond the normal healing period" and has persisted for at least three months. Unfortunately, practical medicine currently lacks safe and effective analgesics capable of replacing opiates and opioids at the second and third steps of the WHO analgesic ladder, i.e., in cases where opiates are necessary for the relief of chronic pain. Therefore, the development of fundamentally new analgesics that, due to their endogenous nature and very low active concentrations, would be capable of replacing opiates and opioids in long-term systemic clinical use for the treatment of chronic and acute pain without causing negative side effects is urgently needed.

[0029] A solution to this technical problem will only be possible if we can discover new molecular mechanisms for signal processing in the nociceptive system (and these mechanisms should be comparable in their physiological effectiveness to the effectiveness of the opioidergic system of the brain), and also develop a medicinal substance of an endogenous nature that would allow pharmacological control over such physiological mechanisms without the occurrence of negative side effects.

[0030] Molecular signaling mechanisms induced by activation of metabotropic receptors, particularly opioid receptors, typically involve G proteins as signal transducers. Exogenous activation of the opioidergic system inevitably results in addiction to opiates and opioids, which modulate these mechanisms, and the manifestation of other negative side effects. It has recently been discovered that the Na,K-ATPase molecule, which is capable of performing not only its pumping function but also acting as a signal transducer, may serve as an alternative to G proteins. It is also known that the transduction function of Na,K-ATPase is modulated by a number of non-peptide compounds, particularly those of endogenous origin, belonging to the class of cardiotonic steroids. Therefore, we have proposed a completely non-obvious hypothesis: this function may also be involved in regulating the responses of the human brain's nociceptive system.The claimed results were obtained through a comprehensive study of various representatives of this class.

[0031] The closest in composition to the claimed medicinal substance is the well-known drug "Strophanthin G", which includes ouabain - a cardiotonic steroid synthesized endogenously in the human body. The drug "Strophanthin G" does not have an analgesic effect and is used for a different medical purpose. "Strophanthin G" is an injectable dosage form (solution for intravenous administration, 0.25 mg / ml [VIDAL, Drug Handbook (https: vidal.rii / drugs / strophanthin-g)]). Excipients: citric acid Acid monohydrate, sodium hydroxide, water for injection. The dose is selected individually depending on the nosology and the patient's response to therapy. At an average rate of digitalization, during the saturation period, 1 ml (0.25 mg) is administered 2 times a day (at 12-hour intervals). The duration of the saturation period is on average 2 days. If necessary, an additional dose of 0.1-0.15 mg can be administered at an interval of 0.5 to 2 hours. The daily dose should not exceed 1 mg, which corresponds to 4 ml of injection solution. The maintenance dose, as a rule, does not exceed 0.25 mg / day. Plasma protein binding is 40%, not subject to metabolism, excreted unchanged by the kidneys. A cardiotonic, antiarrhythmic agent, blocks the pumping function of Na, K-ATPase in the cell membrane of cardiomyocytes.Increases the force and rate of heart contractions (positive ionotropic effect), reduces atrioventricular (AV) conduction (negative dromotropic effect), stimulates (in subtoxic and toxic doses) the formation of heterotopic impulses due to a decrease in the excitability threshold, and reduces the heart rate (HR) - a negative chronotropic effect. Negative side effects of Strophanthin G include cardiac arrhythmias, nausea, vomiting, diarrhea, mesenteric infarction (rarely), headache, increased fatigue, insomnia, depression, hallucinations, psychosis, visual disturbances, and, rarely, gynecomastia. The side effects of this drug are mainly due to its use in relatively high concentrations exceeding endogenous ones, or hypersensitivity to this drug. Too rapid administration may lead to the development of bradyarrhythmia, ventricular tachycardia, atrioventricular block, ventricular fibrillation, and cardiac arrest.Let us note once again that in the world literature there are no results of studies indicating the potential ability of the drug "Strophantin G" or other drugs based on cardiotonic steroids to exhibit an analgesic effect.

[0032] DISCLOSURE OF THE INVENTION

[0033] The essence of the present invention lies in clarifying the physiological role of chelate complexes of cardiotonic steroids (CTS) with divalent inorganic cations (M 2+ ), since, according to our hypothesis, endogenous cardiotonic steroids found in brain tissue and in the human bloodstream in extremely low (nanomolar) concentrations, under physiologically adequate conditions, are in the molecular form of a chelate complex of the general formula CTS-M 2+ A special case of such a complex is the calcium chelate complex of the ouabain molecule (EU), discussed below.

[0034] We have discovered fundamental differences between the effects of EI and the drug "Strophanthin G" (Example 3). The latter contains essentially a free ouabain molecule at a relatively high concentration, which leads to partial inhibition of the pumping function of Na,K-ATPase without producing an analgesic effect. EI (a calcium chelate complex of ouabain), at a much lower concentration, activates the transducer function of Na,K-ATPase, resulting in the manifestation of an analgesic effect. The promise and fundamental difference of the approach we are developing are due to the fact that our proposed endogenous non-peptide substances do not activate opioid receptors, but act on an entirely different molecular membrane target—the Na,K-ATPase molecule, which performs a transducer, rather than a pump, function in the membrane of the nociceptive neuron.Activation of the transducer (non-pump) function of Na,K-ATPase leads to modulation of the slow sodium channels Navi.8, which encode nociceptive (pain) information. Achieving pharmacological control over this mechanism formed the basis for the development of the proposed analgesic substance, a pharmacological composition based on it, and methods of use, which are free of the deficiencies characteristic of the prototype. The development of a medicinal substance based on EU will enable its use as an effective and safe analgesic, capable of replacing opiates in clinical practice by activating a new molecular mechanism of membrane signaling in the nociceptive neuron.

[0035] We have developed an analgesic medicinal substance based on ouabain applied in a wide range of concentrations. This ensures the substance's delivery to its target, the Na,K-ATPase molecule in the membrane of the nociceptive neuron, precisely at endogenous, i.e., nanomolar concentrations, but does not cause partial inhibition of the Na,K-ATPase pumping function, which is achievable with a multiple reduction in the active component concentration compared to Strophanthin G. In this case, according to our data (examples 3, 4), ouabain possesses strong analgesic properties and is also safe for clinical use due to its endogenous nature and low active concentrations. We emphasize that our solution is based on the fact that incubation of ouabain in an aqueous solution containing divalent calcium cations leads to the formation of a stable complex compound (OU), which, in essence, is the active medicinal substance.The ouabain molecule first coordinately binds (chelates) a free calcium cation, thereby forming a medicinal substance. The interaction of this exogenously applied substance with the Na.K-ATPase molecule then leads to the activation of the transducer function of the latter, which causes a decrease in the functional activity of the slow sodium channels Navi.8. This results in pain relief at the spinal and supraspinal levels (Example 3), which is confirmed by the results of clinical studies (Example 4). The present invention describes the creation of a new highly effective analgesic medicinal substance based on cardiotonic steroids (CTS), in particular ES, which does not cause negative side clinical effects, a new pharmaceutical composition based on said substance, and methods of using them for the relief of chronic and acute pain.

[0036] The claimed analgesic substance is a chelate complex of the general formula CTS-M2+ (in particular, EU, which is a chelate complex of the ouabain molecule with the Ca cation 2+ ), where CTS (in particular, the ouabain molecule) is a cardiotonic steroid molecule with the following structural properties (Fig. G):

[0037] 1) the steroid sskelle molecule is a cyclopentaneperhydrophenanthrene structure containing 17 carbon atoms, supplemented with methyl groups at positions 10 and 13, in which the articulation of the AB and CD rings occurs in the cis-position, and the BC rings in the trans-position;

[0038] 2) at position 17 of the steroid skeleton there is a five- or six-membered lactone ring E (cardenolides and bufadienolides, respectively);

[0039] 3) in position 3 of the steroid skeleton there may be a monosaccharide residue or an oligosaccharide chain;

[0040] 4) on the carbon atoms of the A and B rings of the steroid skeleton (atoms C1-C10 according to the generally accepted nomenclature of cardiotonic steroids), including the carbon atom C19, there are at least two hydroxyl substituents involved in the chelation of the cation M 2+ , in addition to the hydroxyl substituent, monosaccharide residue or oligosaccharide chain at position 3;

[0041] M 2+ - any divalent inorganic cation (in particular, Ca 2+ ).

[0042] The claimed pharmaceutical composition has an analgesic effect and includes an active component - a chelate complex of the general formula CTS-M 2+ , as well as a pharmaceutically acceptable carrier (a carrier necessary for the delivery of the analgesic substance to the membrane target molecule, but not affecting the mechanism of chelation of the M cation 2+). The carrier may be selected from the group: water for injection, polyethyleneglycol, glycerol, glycerin. The composition may be formulated for systematic administration—for both external and internal use—as a patch, suppository, solution, suspension, cream, ointment, gel, or in ampoule form; it can act once (instantly) and may be prepared in a form for prolonged action. Use of the composition is non-addictive, and therefore there is no need to continually increase the dosage of the medicinal substance. The components for creating the pharmaceutical composition are technologically available.

[0043] The claimed methods of using the aforementioned pharmaceutical composition include administering it in a therapeutically acceptable amount for pain relief. A single dose of the active component should not exceed 0.1 mg, with the daily dosage of the active component being no more than 0.4 mg for patients weighing 50-100 kg. The composition can be administered intravenously, epidurally, mucosally, cutaneously, parenterally, orally, enterally, intranasally, or rectally. The claimed methods provide an absolutely safe, long-term relief of chronic and acute pain, lasting for 4-6 hours after a single administration of the pharmacological composition, which is comparable in duration to the known effects of opiates and opioids. The claimed methods are gentle, as all components of the pharmaceutical composition used in them are endogenous, and its mechanism of action is purely selective.The claimed methods differ from existing methods in several significant ways: the use of a new endogenous analgesic substance in a specific, limited therapeutic dose, and its universal application across a wide range of routes of administration: intravenous, epidural, mucosal, cutaneous, parenteral, oral, enteral, intranasal, and rectal. No prior art treatments for chronic and acute pain are known that utilize such a subtle, selective effect on the relevant signaling pathways transmitting nociceptive information, resulting in the relief of chronic and acute pain without intoxication or addiction.

[0044] The combination of essential features of the claimed group of inventions enables the following technical result to be achieved. A highly effective analgesic agent of the general formula CTS-M has been created. 2+(in particular, ED), capable of replacing opiates in clinical practice without causing negative pharmacological side effects such as intoxication and addiction. For this reason, the claimed medicinal substance can be used initially in maximum therapeutic daily doses (up to 0.4 mg per day) and achieve an almost immediate effect of relieving acute pain (phase 1), and then tonic pain (phase 2) (Fig. 2). This effect does not affect the opioidergic molecular signaling system and is achieved as a result of the activation of a subtle mechanism of the specific effect of ED on its molecular target - the Na,K-ATPase molecule, which acts as a signal transducer (amplifier and transmitter). This signal reduces the functional activity of slow sodium channels Nav1.8, responsible for the impulse encoding of pain stimuli.As a result, the unique ability of EC to relieve chronic pain over a long period of time (at least four to six hours with a single exposure) is unexpectedly revealed, comparable in duration to the effect of major analgesics.

[0045] BRIEF DESCRIPTION OF DRAWINGS

[0046] Fig. 1 shows the structural data of the ouabain and EU molecules. (A) Structural formula of the ouabain molecule with designation of the steroid skeleton rings and numbering of the carbon atoms. (B) Spatial structure of the lowest-energy conformation of the ouabain molecule based on the results of a full ab initio conformational analysis by the RHF / 6-31G* method and numbering of the oxygen atoms. Carbon atoms are shown as white balls, oxygen atoms as black balls. Hydrogen atoms are shown below. (C) Spatial structure of the lowest-energy conformation of the molecule of the ouabain chelate complex with the calcium cation (EU) based on the results of a full ab initio conformational analysis by the RHF / 6-31G* method and numbering of the oxygen atoms. Carbon atoms are shown as white balls, oxygen atoms as black balls, and the calcium atom as a gray ball. The Ca-O coordination bonds are shown by arrows. Hydrogen atoms are not shown.

[0047] Fig. 2 - analgesic effect of calcium chelate complex ouabain (EU) at supraspinal and spinal levels according to the results of formalin test.

[0048] Fig. 3 - analgesic effect of the calcium chelate complex ouabain (EC), included in the gel when applied topically.

[0049] 1- Intensity of pain before applying the gel to the skin;

[0050] 2 - Intensity of pain after applying the gel to the skin.

[0051] * - p < 0.05 (Student's t-test).

[0052] EXAMPLES OF IMPLEMENTING THE INVENTION

[0053] To confirm the compliance of the claimed solution with the requirement of "industrial applicability," and to better understand the essence of the invention, examples of its specific implementation are provided below, which do not limit the claimed invention. Example 1. Injectable form. A method for producing a pharmaceutical composition containing EC as an active component in the form of a solution.

[0054] The analgesic substance (AS) is a two-component aqueous solution of ouabain and calcium bicarbonate, with calcium bicarbonate present in excess of ouabain. The calcium chelate molecule of ouabain is formed directly in the aqueous solution, which forms the basis of the injection formulation. Description: Clear, colorless, odorless liquid (3 mg / ml). Composition:

[0055] Active ingredient: 3 mg / ml

[0056] Calcium chelate complex 3 g ouabain (EU)

[0057] Excipients:

[0058] Calcium bicarbonate 5.5 g

[0059] Water for injection up to 1 l

[0060] Release form.

[0061] Ampoules of 1, 2 or 5 ml, containing 3 mg / ml of the drug.

[0062] 5 or 10 ampoules in a blister, packed in a cardboard box.

[0063] Example 2. A method for producing a pharmaceutical composition in the form of a gel containing EU as an active component.

[0064] For transdermal delivery of ED, an optimal gel base composition was selected, taking into account the compatibility of its components. Substances of endogenous origin are able to penetrate the epidermis if placed in an amphiphilic base. A standard emulsion is an amphiphilic base and functions as a system for delivering ED to the deep layers of the stratum corneum of the epidermis. First, a gel base was mixed and its stability was tested for one month (no change in pH of more than 0.3 units, colloidal and thermal stability, and microbiological purity were verified). Then, ED was added to the gel base (at a concentration of 0.3%). No changes in the formulation's appearance occurred. The gel composition containing ED was used to obtain clinical impressions after receiving permits (based on the requirements of Technical Regulation of the Customs Union 009 / 2011) for the use of the gel composition as a cosmetic product.

[0065] The developed recipe is presented in Table 1.

[0066] Table 1

[0067] The physicochemical parameters of the gel formulation with EU are given in Table 2.

[0068] Table 2.

[0069] Example 3. Formalin test.

[0070] The formalin test is widely used in many studies to investigate the effects of exogenous and endogenous substances on pain sensitivity, as well as to evaluate the analgesic potency of drugs of various natures. The formalin test was carried out according to a well-known method (Dubuisson D., Dennis SG The formalin test: a quantitative study of the analgesic effects of morphine, meperidine, and brain stem stimulation in rats and cats / / Pain. 1977. V. 4. P. 161-174; Tjolsen A., Berge O.-G., Hunskaar S., Rosland JH, Hole K. The formalin test: an evaluation of the method / / Pain. 1992. V. 51. Henry JL, Yashpal K., Coderre TJ Physiological evidence that the “interphase” in the formal test is due to active inhibition / / Pain. 1999. P. 57-63; peripheral origin of the tonic nociceptive response to subcutaneous formalin / / Pain. 1995. V.61. R.11-16; Abbott FV, Melzack R., Samuel C.Morphine analgesia in the tail-test and formalin pain tests is mediated by different neural systems / / Exp. Neurol. 1982.V.75. P. 644-651; Abbott FV, Ocvirk R, Najafee R et al. Improving the effectiveness of the formalin test / / Pain. 1999. V.83. P. 561-569).

[0071] The studies were performed on 14 experimental male Wistar rats (7 - calcium chelate complex of ouabain (EU) and 7 - the drug "Strophanthin G", containing as an auxiliary cation not Ca 2+ , and Na +The control group consisted of seven adult male rats. The average weight of the animals was 360 g. The experimental rats were administered the drugs at a dose of 0.3 mg / kg, and the control rats were given 1 ml of saline solution intraperitoneally 10 min before the injection of formalin solution (2.5%, 50 μl, subcutaneously into the sole of the left hind limb). Specific reactions of the rats in response to the formalin injection - flexion + shaking (spinal level) and licking (supraspinal level) - were recorded for an hour after the injection of the nociceptive chemical irritant.

[0072] Under standard experimental conditions, two types of pain are observed in the control and experimental groups: 1) acute pain—the first short (less than 5 min) phase caused by the direct effect of formalin on peripheral nociceptive endings; 2) tonic pain—the second long phase, which is determined by sensitization processes in the spinal cord caused by the first phase and afferent signaling from the site of inflammation; the second phase lasts visually 60 min. Between the first and second phases, there is an interphase of no more than 10 minutes, during which no reaction to the inflammatory agent is observed in the animal.

[0073] The protocol recorded the number of "flexions," "shakes," and the duration of "licking" of the left injected limb. Interphase intervals and behavioral responses were assessed: exploratory behavior, grooming, avoidance, and habituation. For control rats, the same sequence of events was observed as for experimental animals: an intraperitoneal injection of saline, 10 minutes later, a formalin injection into the sole of the left hind limb, placement of the rat in a behavioral observation chamber, and recording of flexion and shake responses and the duration of licking responses (in seconds) for an hour.

[0074] Formalin test results.

[0075] Phase 1 (acute phase). The obtained data showed significant differences in the licking patterns of the experimental animals that were exposed to the calcium chelate complex of ouabain (EU): the average value was 6.6 ± 1.6 s. The average value of the responses of the control group of animals was significantly higher: 30.0 ± 11.4 s. This indicates a strong analgesic effect of the claimed substance at the supraspinal level. It is important to emphasize that when exposed to the drug "Strophanthin G", the responses of the experimental animals (ouabain with Na + was administered at the same concentration of 0.3 mg / kg) and animals of the control group did not differ significantly: 35.1 ±8.1 vv 30.0 ±11.4 s.

[0076] Significant differences in flexion and shaking patterns were also revealed between control animals (95.7±21.5) and experimental animals after exposure to the calcium chelate complex ouabain (EC) (24.3±3.1). This indicates its strong analgesic effect at the spinal level. When exposed to the drug "Strophanthin G," the responses of experimental animals and control animals did not differ significantly.

[0077] In conclusion, an acute pain study (Phase 1) showed that ouabain calcium chelate (OU) exhibits potent analgesic properties at both spinal and supraspinal levels.

[0078] Phase 2 (tonic phase).

[0079] The obtained data revealed significant differences in licking patterns between control animals (196.8±37.8) and experimental animals after exposure to the calcium chelate complex ouabain (EC) (44.8±17.3). When exposed to the drug "Strophanthin G," the responses of experimental animals and control animals did not differ significantly. Thus, at the supraspinal level, the claimed substance has a strong analgesic effect.

[0080] Significant differences were also found in the flexion and shaking patterns between control animals (561.5 ± 58.4) and experimental animals after exposure to ouabain calcium chelate complex (OU) (175.0 ± 49.3), indicating its strong analgesic effect at the spinal level. Strophanthin G produced a weak analgesic effect compared to the responses of experimental animals. This effect was two times weaker than the strong analgesic effect of ouabain calcium chelate complex (OU).

[0081] A study of tonic pain (Phase 2) demonstrated that ouabain calcium chelate (OU) exhibits strong analgesic properties at both the spinal and supraspinal levels. Behavioral experiments conducted allow the following conclusions to be drawn:

[0082] 1. Injection of calcium chelate complex ouabain (EU) to rats at a dose of 0.3 mg / kg, in contrast to injection of the drug "Strophanthin G", causes a strong analgesic effect at both the spinal and supraspinal levels.

[0083] 2. A strong analgesic effect of EU is observed in both acute and tonic pain.

[0084] 3. Observations of experimental animals showed that in no case did a reaction of addiction to the action of the studied substance appear.

[0085] Example 4. An initiative clinical study of the analgesic effect of the calcium chelate complex ouabain (EU).

[0086] To address the objectives, a group of 30 patients was recruited, each suffering from chronic nonspecific back pain or limb pain of unspecified severity. All patients complained of moderate to severe pain intensity, assessed using a verbal-numerical scale. The study was approved by the local ethics committee.

[0087] After inclusion in the study group, the patient was interviewed to characterize their pain sensations and assess their intensity. Then, 1-2 grams of approved EI gel was applied to the skin and rubbed in gently. Application was performed in the area of ​​pain, where its maximum intensity was determined. After 60 and 120 minutes, the patient was re-interviewed to identify changes in pain characteristics. Changes in pain intensity were also assessed using a verbal-numeric scale. In addition, the gel application site was examined to detect local changes on the skin, and skin sensitivity to touch was determined at the site of gel application.

[0088] (non-occipital tactile sensation). The gel was reapplied after 48 hours; at this point, local changes in the skin at the initial treatment site were assessed. The next gel application was performed after another 48-72 hours. A final pain intensity assessment using a verbal-numerical scale was performed 48 hours after the third gel application.

[0089] Examination of patients before cutaneous application of a gel containing EI revealed that aching pain predominates in chronic nonspecific back pain and pain in the extremities. Burning pain was detected in two cases, and in both cases the pain was localized in the back. After application of the gel, pain intensity decreased in the overwhelming majority of cases. When comparing pain intensity values ​​before and 60 minutes after gel application, a statistically significant difference was found (t=8.1; p<0.05 - Student's t-test for related samples). The same result was found 120 minutes after gel application to the skin (t=8.1; p<0.05 Student's t-test for related samples). Touching the skin area where the gel was applied caused a weakened non-nociceptive tactile sensation compared to other areas of the skin, i.e. Hypoesthesia was observed.Upon examination of the skin at the gel application site after 60 minutes, mild hyperemia (blood engorgement of the skin's circulatory system) was observed in two patients. This hyperemia was not detectable after 48 hours and did not impact further study planning. No other changes (itching, flaking, etc.) were observed. The remaining patients did not report any skin changes. Analysis of data obtained after a week-long course of treatment, consisting of three applications of the EI-containing gel to the skin, revealed a statistically significant difference in pain intensity between baseline values ​​and post-treatment data (Fig. 3).

[0090] As a result of the study, it became clear that a gel containing EU, when applied to the skin, is capable of reducing the intensity of chronic pain in the back and limbs.

[0091] The results obtained using a verbal-numeric scale after a week-long course of treatment, consisting of three applications of the gel containing EI to the skin, demonstrate a statistically significant difference in the intensity of pain sensations between the initial values ​​and the values ​​after completion of the course.

[0092] The obtained data indicate the potential of replacing analgesic drugs that have negative side effects when administered systemically with a highly effective calcium chelate complex of ouabain (EU), the low (endogenous) concentrations of which ensure the safety of its use.

Claims

The amended claim was received by the International Bureau on August 2, 2024 (02.08.2024) Invention formula 1. A pharmaceutical composition with an analgesic effect, including an active component - an analgesic substance, which is a chelate complex of ouabain-Ca 2+ , where ouabain is a cardiotonic steroid molecule with the following structural properties: 1) the steroid skeleton of the molecule is a cyclopentaneperhydrophenanthrene structure containing 17 carbon atoms, supplemented with methyl groups at positions 10 and 13, in which the articulation of the rings AB and CD are carried out in the cis-position, and the BC rings in the trans-position; 2) at position 17 of the steroid skeleton there is a five-membered lactone ring E; 3) at position 3 of the steroid skeleton there is a monosaccharide residue; 4) at carbon atoms 1-10 of the A and B rings of the steroid skeleton, according to the nomenclature of steroids and the C19 carbon atom, there are at least two hydroxyl substituents involved in the chelation of the Ca cation 2+ , in addition to the monosaccharide residue at position 3; and a pharmaceutically acceptable carrier.

2. The composition according to claim 1, characterized in that the pharmaceutically acceptable carrier is water for injection.

3. The composition according to claim 1, characterized in that it is made in a form for intravenous, epidural, mucosal, cutaneous, parenteral, oral, enteral, intranasal or rectal administration.

4. The composition according to paragraph 1, characterized in that it is made in the form of a patch, suppository, solution, suspension, cream, ointment, gel, in ampoule form.

5. The composition according to claim 1, characterized in that the carrier is selected from the group: polyethylene glycol, water for injection, glycerin.

6. A method for relieving pain syndrome, which consists of activating the transducer (non-pumping) function of Na,K-ATPase, including the administration of a pharmaceutical composition having an analgesic effect, including an active component, an analgesic substance, which is a chelate complex of ouabain-Ca 2+ , where ouabain is a cardiotonic steroid molecule with the following structural properties: 1) the steroid skeleton of the molecule is a cyclopentaneperhydrophenanthrene structure containing 17 carbon atoms supplemented with methyl groups at positions 10 and 13, in which the ring joints AB and CD are carried out in the cis-position, and the BC rings in the trans-position; 2) at position 17 of the steroid skeleton there is a five-membered lactone ring E; 3) at position 3 of the steroid skeleton there is a monosaccharide residue; 4) on carbon atoms 1-10 of rings A and B of the steroid skeleton according to the nomenclature of steroids and carbon atom C19 there are at least two hydroxyl substituents involved in the chelation of the Ca cation 2+ , in addition to the monosaccharide residue at position 3, and a pharmaceutically acceptable carrier.

7. The method according to item 6, characterized in that the pharmaceutically acceptable carrier is water for injection, polyethylene glycol, or glycerin.

8. A method for relieving pain syndrome, which consists of activating the transducer (non-pumping) function of Na,K-ATPase, including the administration of a pharmaceutical composition having an analgesic effect, including an active component, an analgesic substance, which is a chelate complex of ouabain-Ca 2+ , where ouabain is a cardiotonic steroid molecule with the following structural properties: 1) the steroid skeleton of the molecule is a cyclopentaneperhydrophenanthrene structure containing 17 carbon atoms, supplemented with methyl groups at positions 10 and 13, in which the articulation of the rings AB and CD are carried out in the cis-position, and the BC rings in the trans-position; 2) at position 17 of the steroid skeleton there is a five-membered lactone ring E; 3) at position 3 of the steroid skeleton there is a monosaccharide residue; 4) on carbon atoms 1-10 of rings A and B of the steroid skeleton according to the nomenclature of steroids and carbon atom C19 there are at least two hydroxyl substituents involved in the chelation of the Ca cation 2+, in addition to the monosaccharide residue at position 3, and a pharmaceutically acceptable carrier, characterized in that the composition is used in a form for intravenous, intramuscular, spinal, epidural, mucosal, cutaneous, parenteral, oral, enteral, intranasal or rectal administration.

9. The method according to item 8, characterized in that the pharmaceutically acceptable carrier is water for injection, polyethylene glycol, or glycerin.

10. A method for relieving pain syndrome, which consists of activating the transducer (non-pumping) function of Na,K-ATPase, including the administration of a pharmaceutical composition having an analgesic effect, including an active component, an analgesic substance, which is a chelate complex of ouabain-Ca 2+ , where ouabain is a cardiotonic steroid molecule with the following structural properties: 1) the steroid skeleton of the molecule is a cyclopentaneperhydrophenanthrene structure containing 17 carbon atoms, supplemented with methyl groups in positions 10 and 13, in which the articulation of the AB and CD rings occurs in the cis position, and the BC rings in the trans position; 2) at position 17 of the steroid skeleton there is a five-membered lactone ring E; 3) at position 3 of the steroid skeleton there is a monosaccharide residue; 4) at carbon atoms 1-10 of the A and B rings of the steroid skeleton, according to the nomenclature of steroids and the C19 carbon atom, there are at least two hydroxyl substituents involved in the chelation of the Ca cation 2+, in addition to the monosaccharide residue at position 3, and a pharmaceutically acceptable carrier, characterized in that the composition is administered in a single dose with an active component content of no more than 0.1 mg, while the daily dosage of the active component is no more than 0.4 mg for patients with a body weight of 50 - 100 kg.

11. The method according to item 10, characterized in that the pharmaceutically acceptable carrier is water for injection, polyethylene glycol, or glycerin.

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