JP7406266B2 - analgesic composition - Google Patents

Description

GOVERNMENT SUPPORT This invention was made with government support from the National Institutes of Health (Grant No. R44-AA-009930). The United States Government has certain rights in this invention.

FIELD OF THE INVENTION The present invention relates to analgesic compositions comprising aminoquinoline compounds together with opioids, norepinephrine/serotonin reuptake inhibitors, and/or nonsteroidal anti-inflammatory drugs (NSAIDs).

BACKGROUND OF THE INVENTION Acute pain in response to injury is an important mechanism for reducing the extent of injury to an individual, but the nervous system undergoes adaptive changes that extend beyond the point after the injury has healed. can also result in significant perceived pain (chronic pain) (Costigan et al., 2009). This chronic pain may be caused by stimuli that are normally non-noxious (allodynia), or the response to noxious stimuli may be greatly exacerbated (hyperalgesia). Chronic pain is estimated to affect at least 100 million adults in the United States and can negatively impact quality of life (Institute of Medicine, 2011). Pharmacological treatment of chronic neuropathic pain (resulting from nerve damage) or other chronic pain relies heavily on the use of opiates or their derivatives (Reuben et al., 2015). These drugs have many adverse effects, including tolerance/hyperalgesia leading to dose escalation and the development of opiate addiction (Chou et al., 2015). Additional side effects of high and chronic administration of opiates include constipation, sleep-disordered breathing, bone fractures, hypothalamic-pituitary adrenal axis dysregulation and overdose, and effects on the cardiovascular and immune systems (Baldini et al., 2012). Other drugs, including nonsteroidal antibiotics (NSAIDs), anticonvulsants, muscle relaxants and antidepressants, as well as drugs that target voltage-sensitive calcium channels (gabapentin and pregabalin), have been used to treat chronic pain. used, but these treatments provide limited relief (Lunn et al., 2014; Moore et al., 2014; Schreiber et al., 2015; Smith et al., 2012; Sofat et al. , 2017; Lozada, et al., 2008). Furthermore, chronic administration of high doses of NSAIDs, which are the second most commonly used drugs after opioids to treat chronic pain, can cause side effects such as gastric symptoms (such as bleeding, ulcers, and heaviness), renal failure, high blood pressure, and It is associated with polycythemia, including cardiac symptoms, fluid retention, skin rashes or other allergic reactions (Marcum and Hanlon 2010). A third category of drugs to treat chronic pain is the more recently introduced blockers of the 5-HT and NE reuptake systems (Smith et al., 2012; Sofat et al., 2017). 5-HT/NE reuptake inhibitors also inhibit nausea, G.I. I. It exhibits a range of side effects, including fatigue, difficulty sleeping, and fatigue. More dangerous is the effect of hastily discontinuing the use of these drugs if they do not relieve chronic pain. Such “withdrawal” effects include excessive mood swings, agitation, aggression, nightmares, confusion, and electric shock-like sensations in the head and other parts of the body (Fava et al., 2018; Carvalho et al., 2016). In all cases, dose escalation for therapeutic success with opiates/opioids, NSAIDs or 5-HT/NE reuptake inhibitors for chronic pain results in the appearance of serious side effects and the use of this drug. Careless discontinuation of treatment may result in more serious side effects.

Most chronic pain sufferers continue to use prescribed opiates/opioids in high doses for long periods of time if their pain is not controlled by other drug classes. Due to the significant increase in the use of opiates to treat chronic pain and the resulting concerns about overdose, misuse, or diversion problems (referred to as the "opioid crisis"), prescribed opioids must be administered at the lowest effective doses and for the shortest possible time. It is recommended to limit the duration of efficacy and, importantly, to develop novel non-opioid drug treatments based on scientific information about the pathogenesis of chronic pain (Volkow and McLellan 2016 ; Taneja et al., 2017; Kirkpatrick et al., 2016).

Many attempts have been made to create new and better pain drug treatments by focusing on targets known to be involved in chronic pain (Yekirala, et al., 2017; Worley 2017). Target selection is a major focus of chronic pain drug development efforts, and most plans use a single target/site (e.g., receptor), which has been the pharmaceutical industry's approach of choice for many years. (Ramsay et al., 2018). However, targeting a single molecular entity to control complex physiological systems limits the efficacy of drugs (Bozic et al., 2013). In more recent years, perceptions have changed, due in part to designing effective multi-targeted drugs for the treatment of schizophrenia, viral infections, asthma, cardiovascular disease, neurodegenerative diseases and cancer. (Ramsay et al., 2018). Such drugs result in partial inhibition of one or more targets within a network rather than complete inhibition of a single target (Zimmerman et al., 2007; Millan, 2014; Talevi, 2015) .

With respect to pain, one can focus on the systems that process sensory information from peripheral receptors and the systems that transduce information within and between sensory neurons. One of the most studied molecular mechanisms leading to chronic neuropathic pain syndromes is the upregulation of peripheral voltage-sensitive sodium channel (VSNaC) activity (Wood et al., 2004; Lai, et al., 2004; Black et al., 2004; Coggeshall et al., 2004; Dib-Hajj et al., 2007). Tetrodotoxin-sensitive Nav1.7 channels are located along the processes and cell bodies of slowly processing nociceptive neurons, and their role in both acute and chronic pain occurs through genetic manipulation in animals and naturally in humans. This has been clearly demonstrated by genetic mutations (Black et al., 2004; Wang et al., 2011; Lawrence, 2012). Nav1.7 channels are particularly linked to inflammation-related pain, and its upregulation contributes to increased action potential generation and processing in chronic pain syndromes (Eijkelkamp et al., 2012). Furthermore, the activity of Nav1.7 channels can amplify the orbital potential and promote the activation of other sensory neurons VSNaC, including tetrodotoxin-resistant Nav1.8 channels (Dib-Hajj et al., 2007 ; Choi & Waxman, 2011). Nav1.8 channels have been linked to the development of both inflammatory and neuropathic pain conditions. Altogether, upregulation of the activity of Nav1.7 and Nav1.8 channels in peripheral sensory neurons constitutes a common element in the induction and maintenance of chronic pain syndromes (Wang et al., 2011; Theile & Cummins, 2011 ; Laedermann et al., 2015).

The role of the excitatory amino acid glutamate in the physiology of normal pain sensing and in the transmission of chronic pain phenomena is also well established (Davies & Lodge, 1987; Dickenson & Sullivan, 1987; Childers & Baudy, 2007). Activation or injury of sensory neurons causes increased release of glutamate from both peripheral and central neurons, and the released glutamate acts on nearby glutamate (NMDA) receptors, leading to peripheral sensitization. (Fernandez-Montoya et al., 2017; Jang et al., 2004). The interaction of glutamate with NMDA receptors in the dorsal root ganglion (DRG) is also involved in the amplification of sensory signals (Ferrari et al., 2014; Rozanski et al., 2013). Thus, NMDA receptors are involved in both the initiation and amplification of pain sensation and its transmission to the CNS. Upregulation of NMDA receptors is seen in both peripheral neurons and the spinal cord after sensory nerve injury, and it is thought that upregulation contributes to chronic neuropathic pain (Petrenko et al., 2003). In detail, the amount of GluN2B (NR2B) subunit-containing NMDA receptors plays the most important role in the development and maintenance of chronic pain syndromes (Karlsson et al., 2002; Iwata et al., 2007; Gaunitz et al. , 2002; Wilson et al., 2005).

Based on this discussion, drug treatments that can simultaneously inhibit Nav1.7 channel activity and Nav1.8 channel activity and inhibit the activity of NMDA receptors (specifically, NMDA receptors containing GluN2B subunits) are It may be beneficial both in preventing the development of chronic pain by inhibiting upregulation and in alleviating pain even after the onset of chronic pain syndromes. Such drug treatments need not act in the central nervous system and may prevent central sensitization and peripheral sensitization that leads to the development of chronic pain, and/or inhibit the initiation and transmission of chronic pain signals to the brain. It can be weakened.

Costigan et al. ,2009 Institute of Medicine, 2011 Reuben et al. ,2015 Chou et al. ,2015 Baldini et al. ,2012 Lunn et al. ,2014 Moore et al. ,2014 Schreiber et al. ,2015 Smith et al. ,2012 Sofat et al. ,2017 Lozada, et al. ,2008 Marcum and Hanlon 2010 Fava et al. ,2018 Carvalho et al. ,2016 Volkow and McLellan 2016 Taneja et al. ,2017 Kirkpatrick et al. ,2016 Yekkirala, et al. ,2017 Worley 2017 Ramsay et al. ,2018 Bozic et al. ,2013 Ramsay et al. ,2018 Zimmerman et al. ,2007 Millan, 2014 Talevi, 2015 Wood et al. ,2004 Lai, et al. ,2004 Black et al. ,2004 Coggeshall et al. ,2004 Dib-Hajj et al. ,2007 Wang et al. ,2011 Lawrence, 2012 Eijkelkamp et al. ,2012 Dib-Hajj et al. ,2007 Choi & Waxman, 2011 Theile & Cummins, 2011 Laedermann et al. ,2015 Davies & Lodge, 1987 Dickenson & Sullivan, 1987 Childers & Baudy, 2007 Fernandez-Montoya et al. ,2017 Jang et al. ,2004 Ferrari et al. ,2014 Rozanski et al. ,2013 Petrenko et al. ,2003 Karlsson et al. ,2002 Iwata et al. ,2007 Gaunitz et al. ,2002 Wilson et al. ,2005

SUMMARY OF THE INVENTION N-substituted-4-ureido-5,7-dichloro-2-carboxy (or carboxy ester) quinolines in combination with opioids, NE/5-HT reuptake inhibitors or NSAIDs are effective in treating chronic neurological disorders in humans. It is effective in the treatment and prevention of sexual pain.

Analgesic compositions embodying the invention include an aminoquinoline compound together with an opioid, a NE/5-HT reuptake inhibitor, a nonsteroidal anti-inflammatory drug (NSAID), or a combination thereof. Aminoquinoline compounds enhance the biological activity of opioids, drugs that block the uptake of serotonin (5-HT) and norepinephrine (NE), and NSAIDs. As a result, co-administration of aminoquinoline compounds makes it possible to reduce the dose of the opioid, NE or 5HT reuptake blocker, or NSAID used for the desired analgesic (anthyperalgesic) effect. Additionally, aminoquinoline compounds, if administered early in the course of chronic pain development, may present with the onset of chronic pain and/or worsening of chronic pain syndromes.

Formula (I):

によって表されるアミノキノリン化合物において、その置換基は、以下のように定義される：Ｒ^１は、Ｈ、Ｃ_２－Ｃ_４アルキル、Ｃ_２－Ｃ_４アルケニル、ハロ、Ｚ^１Ｒ^９、又はＮ（Ｒ^１０）（Ｒ^１１）である。Ｒ^２は、Ｈ、Ｃ_１－Ｃ_４アルキル、Ｃ_２－Ｃ_４アルケニル、ハロ、Ｚ^２Ｒ^１２、Ｎ（Ｒ^１３）（Ｒ^１４）、又はＣ_１－Ｃ_４アルキル、Ｃ_２－Ｃ_４アルケニル、ハロ、Ｚ^３Ｒ^１５、Ｎ（Ｒ^１６）（Ｒ^１７）からなる群より選択される１つ以上の部分によって置換されるＣ_１－Ｃ_４アルキルであり；各Ｒ^３、Ｒ^４、Ｒ^５、及びＲ^６は、独立してＨ、Ｃ_１－Ｃ_４アルキル、Ｃ_２－Ｃ_４アルケニル、ハロ、Ｚ^３Ｒ^１８、又はＮ（Ｒ^１９）（Ｒ^２０）であり；Ｘ^１は、Ｎ又はＣＨであり；各Ｒ^７及びＲ^８は、独立してＨ、Ｃ_１－Ｃ_６アルキル、Ｃ_２－Ｃ_４アルケニル、Ｃ_２－Ｃ_４アルキニル、アリール、又はＣ_１－Ｃ_４アルキル、Ｃ_２－Ｃ_４アルケニル、ニトロ、ハロ、Ｚ^４Ｒ^２１、及びＮ（Ｒ^２２）（Ｒ^２３）からなる群より選択される１つ以上の部分によって置換されるＣ_１－Ｃ_６アルキルであるか；又はＲ^７及びＲ^８は、Ｘ^１と共に５～８員の飽和、不飽和、又は芳香族有機環式部分又は複素環式部分を形成し；各Ｒ^９、Ｒ^１０、Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ｒ^１５、Ｒ^１６、Ｒ^１７、Ｒ^１８、Ｒ^１９、Ｒ^２０、Ｒ^２１、Ｒ^２２、及びＲ^２３は、独立してＨ、Ｃ_１－Ｃ_４アルキル、又はＣ_１－Ｃ_４アルキル、Ｃ_２－Ｃ_４アルケニル、Ｃ_２－Ｃ_４アルキニル、ハロ、ヘテロアリール、Ｚ^５Ｒ^２４、及びＮ（Ｒ^２５）（Ｒ^２６）からなる群より選択される１つ以上の部分によって置換されるＣ_１－Ｃ_４アルキルである。Ｚ^１、Ｚ^２、Ｚ^３、Ｚ^４、及びＺ^５の各々は、独立してＯ、Ｓ、ＮＨ、Ｃ（＝Ｏ）Ｏ、Ｏ－Ｃ（＝Ｏ）、Ｃ（＝Ｏ）、又はＣ（＝Ｏ）ＮＨである。Ｒ^１がＺ^１Ｒ^９であり、Ｚ^１がＣ（＝Ｏ）Ｏであり、Ｒ^９がＨ又はＣ_１－Ｃ_２アルキルであり、Ｒ^３及びＲ^５の各々がハロであり、Ｘ^１がＮであり、かつＲ^４及びＲ^６の各々がＨであって、次いでＲ^７及びＲ^８の少なくとも１つはフェニル、アルコキシ－置換フェニル、又はＣ_１－Ｃ_６アルキル基である場合に、各Ｒ^２４、Ｒ^２５、及びＲ^２６は、独立してＣ_１－Ｃ_４アルキルである。

In the aminoquinoline compound represented by, the substituents are defined as follows: R ¹ is H, C ₂ -C ₄ alkyl, C ₂ -C ₄ alkenyl, halo, Z ¹ R ⁹ , or N(R ¹⁰ )(R ¹¹ ). R ² is H, C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, halo, Z ² R ¹² , N(R ¹³ )(R ¹⁴ ), or C ₁ -C ₄ alkyl, C ₂ -C ₄ ^each _R ^{3 ,} _R ^{4 ; _} R ⁵ and R ⁶ are independently H, C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, halo, Z ³ R ¹⁸ , or N(R ¹⁹ )( ^{R 20} ); , N or CH; each R ⁷ and R ⁸ is independently H, C ₁ -C ₆ alkyl, C ₂ -C ₄ alkenyl, C ₂ -C ₄ alkynyl, aryl, or C ₁ -C ₄ alkyl , C ₁ -C ₆ alkyl substituted by one or more moieties selected from the group consisting of , C ₂ -C ₄ alkenyl, nitro, halo, Z ⁴ R ²¹ , and N(R ²² )(R ²³ ); or R ⁷ and R ⁸ together with X ¹ form a 5- to 8-membered saturated, unsaturated, or aromatic organic cyclic moiety or heterocyclic moiety; each R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² and R ²³ are independently H, C ₁ -C ₄ alkyl, or 1 selected from the group consisting of C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, C ₂ -C ₄ alkynyl, halo, heteroaryl, Z ⁵ R ²⁴ , and N(R ²⁵ )(R ²⁶ ) C ₁ -C ₄ alkyl substituted by one or more moieties. Each of Z ¹ , Z ² , Z ³ , Z ⁴ , and Z ⁵ is independently O, S, NH, C(=O)O, OC(=O), C(=O), or C(=O)NH. R ¹ is Z ¹ R ⁹ , Z ¹ is C(=O)O, R ⁹ is H or C ₁ -C ₂ alkyl, each of R ³ and R ⁵ is halo, and X ¹ is N, and each of R ⁴ and R ⁶ is H, and then at least one of R ⁷ and R ⁸ is phenyl, alkoxy-substituted phenyl, or a C ₁ -C ₆ alkyl group, Each R ²⁴ , R ²⁵ , and R ²⁶ is independently C ₁ -C ₄ alkyl.

Formula (II):

のアミノキノリン化合物において、Ｘ^１、Ｒ^１、Ｒ^７及びＲ^８は、上記式（Ｉ）において定義される通りであり、そして各Ｘ^２及びＸ^３は、独立してハロ、ニトロなどの電子求引基であるが、ただし、Ｒ^１がＺ^１Ｒ^９であり、Ｚ^１がＣ（＝Ｏ）Ｏ又はＣ（＝Ｏ）であり、Ｒ^９がＨ又はＣ_１－Ｃ_４アルキルであり、そしてＸ^１がＮである場合に、Ｒ^７及びＲ^８の少なくとも１つは、フェニル又はアルコキシで置換された基ではないという条件の上である。

In the aminoquinoline compound, X ¹ , R ¹ , R ⁷ and R ⁸ are as defined in formula (I) above, and each X ^{2 and} is an attracting group, provided that R ¹ is Z ¹ R ⁹ , Z ¹ is C(=O)O or C(=O), and R ⁹ is H or C ₁ -C ₄ alkyl; , and when X ¹ is N, provided that at least one of R ⁷ and R ⁸ is not a phenyl or alkoxy-substituted group.

Formula (III):

のアミノキノリン化合物において、Ｘ^２及びＸ^３は、各々独立してハロであり、そしてＸ^１、Ｒ^１、Ｒ^７、Ｒ^８及びＲ^９の各々は、上述の式（Ｉ）及び（ＩＩ）において定義される通りであるが、ただし、Ｒ^９がＨ又はＣ_１－Ｃ_２アルキルであり、そしてＸ^１がＮである場合、Ｒ^７及びＲ^８の少なくとも１つは、フェニル又はアルコキシで置換されたフェニル基ではないという条件の上である。

In the aminoquinoline compound of formulas (I) and (II), X ² and X ³ are each independently halo, and each of X ¹ , R ¹ , R ⁷ , R ⁸ and R ⁹ has with the proviso that when R ⁹ is H or C ₁ -C ₂ alkyl and X ¹ is N, at least one of R ⁷ and R ⁸ is substituted with phenyl or alkoxy. This is on the condition that it is not a phenyl group.

Formula (IV):

のアミノキノリン化合物において、Ｘ^２、Ｘ^３、Ｒ^１、Ｒ^７、及びＲ^８の各々は、上記式（Ｉ）及び（ＩＩ）において定義される通りである。

In the aminoquinoline compound, each of X ² , X ³ , R ¹ , R ⁷ , and R ⁸ is as defined in formulas (I) and (II) above.

Formula (V):

のアミノキノリン化合物において、Ｘ^２、Ｘ^３、Ｒ^７、Ｒ^８及びＲ^９の各々は、上記式（Ｉ）及び（ＩＩ）において定義される通りである。

In the aminoquinoline compound, each of X ² , X ³ , R ⁷ , R ⁸ and R ⁹ is as defined in formulas (I) and (II) above.

Formula (VI):

のアミノキノリン化合物において、Ｒ^７は、アルキル、シクロアルキル、アミノアルキル又はフェニルであり；Ｒ^８は、Ｈ、アルキル、シクロアルキル、アミノアルキル、又はフェニルであり；Ｅ^１は、－Ｃ（＝Ｏ）ＯＲ^９、－Ｃ（＝Ｏ）Ｒ^９、－Ｃ（＝Ｏ）Ｎ（Ｒ^９）_２、及び－［Ｃ（Ｒ^９）_２］_ｎ－ＯＲ^９であり、「ｎ」は、１、２、３、又は４であり；各Ｒ^９は、独立してＨ、Ｃ_１－Ｃ_４アルキル、又はＣ_１－Ｃ_４アルキル、Ｃ_２－Ｃ_４アルケニル、Ｃ_２－Ｃ_４アルキニル、ハロ、ヘテロアリール、Ｚ^５Ｒ^２４、及びＮ（Ｒ^２５）（Ｒ^２６）からなる群より選択される１つ以上の部分によって置換されるＣ_１－Ｃ_４アルキルであり；Ｚ^５は、Ｏ、Ｓ、Ｃ（＝Ｏ）Ｏ又はＯ－Ｃ（＝Ｏ）であり；各Ｒ^２４、Ｒ^２５、及びＲ^２６は、独立してＣ_１－Ｃ_４アルキル、アルキルであり；各Ｘ^２及びＸ^３は、独立して電子求引基（好ましくはハロゲン又はニトロ）であり；アルキル、シクロアルキル、アミノアルキル、及びフェニル基は、置換されていなくても、アルキル（１～３炭素）基又はアルキルオキシ基（例えば、１～３炭素のアルキル又はアルコキシ基）によって１回以上置換されていてもよく；そして酸性又は塩基性の官能基が存在する場合、化合物は、遊離の酸性形態であっても、遊離の塩基性形態であっても、又は薬理学的に許容される付加塩であってもよい。Ｅ^１がＣ（＝Ｏ）ＯＲ^９である場合、Ｒ^７及びＲ^８の少なくとも１つは、フェニルではない。

In the aminoquinoline compound of R ⁷ is alkyl, cycloalkyl, aminoalkyl or phenyl; R ⁸ is H, alkyl, cycloalkyl, aminoalkyl or phenyl; E ¹ is -C(=O )OR ⁹ , -C(=O)R ⁹ , -C(=O)N(R ⁹ ) ₂ , and -[C(R ⁹ ) ₂ ] _n -OR ⁹ , where "n" is 1, 2, 3, or 4; each R ⁹ is independently H, C ₁ -C ₄ alkyl, or C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, C ₂ -C ₄ alkynyl, halo, heteroaryl, Z ⁵ R ²⁴ , and C ₁ -C ₄ alkyl substituted by one or more moieties selected from the group consisting of N(R ²⁵ )(R ²⁶ ); Z ⁵ is O, S , C(=O)O or O-C(=O); each R ²⁴ , R ²⁵ , and R ²⁶ is independently C ₁ -C ₄ alkyl, alkyl; each X ² and X ³ are independently electron-withdrawing groups (preferably halogen or nitro); alkyl, cycloalkyl, aminoalkyl, and phenyl groups, even if unsubstituted, are alkyl (1-3 carbon) groups or alkyloxy It may be substituted one or more times by groups (e.g. alkyl or alkoxy groups of 1 to 3 carbons); and if acidic or basic functionality is present, the compound may be substituted even in the free acidic form. It may be in its free basic form or as a pharmacologically acceptable addition salt. When E ¹ is C(=O)OR ⁹ , at least one of R ⁷ and R ⁸ is not phenyl.

Particularly preferred for use in the analgesic compositions of the present application are compounds of formula (VI) in free acidic form, free basic form, or as a pharmacologically acceptable addition salt, where:
R ⁷ is alkyl (preferably 3-6 carbon alkyl) or phenyl;
R ⁸ is alkyl (preferably 3-6 carbon alkyl) or phenyl;
E ¹ is -C(=O)R ⁹ or E ¹ is -C(=O)OR ⁹ ;
Each R ⁹ is H or C ₁ -C ₄ alkyl; and each X ² and X ³ is independently an electron withdrawing group (preferably halogen or nitro).

Administration of the analgesic composition may be by oral, subcutaneous, intravenous, intramuscular, intraperitoneal, transdermal or transbuccal routes.

Non-limiting examples of compounds of general formula (VI) include derivatives of 2-carboxy-quinolines, such as (N,N-dibutyl)-4-ureido-5,7-dichloro-2-carboxy-quinoline (BCUKA ), (N,N-diphenyl)-4-ureido-5,7-dichloro-2-carboxy-quinoline (DCUKA), and the like.

Di-substituted-4-ureido-5,7-dichloro-2-carboxy-quinoline compounds of formula (VI) have affinity for some or all of the following: Nav1.7, Nav1.8, and NMDA receptors. . These compounds have beneficial activity in the treatment of degenerative joint pain (e.g. osteoarthritis) and chronic pain syndromes resulting from inflammatory and organic damage to peripheral nerves, including organic or thermal allodynia/hyperalgesia. effectively alleviate.

Compounds of formula (VI) are synthesized from 5,7-dichloroquinolone-2-carboxylate intermediates (e.g., Michael addition of 3,5-dichloroaniline to dimethylacetylene dicarboxylate and subsequent thermal cyclization of the resulting aryl maleate). (4-amino)-5,7-dichloro-2-carboxy-quinoline ethyl ester (key intermediate) by amidation with chlorosulfonyl isocyanate of obtained, which can be functionalized through reaction with relevant electrophiles. For the preparation of monosubstituted ureas, a reactive urea intermediate is prepared through reaction of a primary amine with carbonyldiimidazole. Reaction of the resulting imidazole urea with amino-5,7-dichloro-2-carboxy-quinoline ethyl ester in the presence of sodium hydroxide converts the target monosubstituted urea into the 4-position of the quinoline with simultaneous ester hydrolysis. arise. Removal of protecting groups, such as tert-butoxycarbonyl (BOC)-protecting groups, such as those used in the synthesis of reactive urea intermediates, is accomplished with trifluoroacetic acid (TFA) to yield the desired TFA salt. can occur.

For the preparation of disubstituted urea derivatives, (4-amino)-5,7-dichloro-2-carboxy-quinoline methyl or ethyl ester is acetylated by a disubstituted carbamoyl chloride at the 4-amino position and ( N,N-disubstituted)-4-ureido-5,7-dichloro-2-carboxy-quinoline ester is formed. Optionally, the (N,N-disubstituted)-4-ureido-5,7-dichloro-2-carboxy-quinoline-ester is hydrolyzed to form the (N,N-disubstituted)-4-ureido -5,7-dichloro-2-carboxy-quinoline.

DCUKA and DCUK-OEt show affinity for Nav1.7 and Nav1.8, respectively, and DCUKA also shows affinity for NMDA receptors. DCUK-OEt can also act as a prodrug of DCUKA due to ester hydrolysis by carboxylesterase 1 that occurs after in vivo administration.

Figure 3 illustrates that DCUK-OEt can act as a prodrug for DCUKA. When DCUK-OEt was orally administered to rats in a suspension in a spray-dried dispersion formulation, the data show that blood levels of DCUKA were dependent on the dose of DCUK-OEt administered. Peak levels of DCUKA are approximately 3 μM after administration of a 50 mg/kg dose of DCUK-OEt and approximately 11 μM after administration of a 100 mg/kg dose of DCUK-OEt. Figure 2 illustrates treatment of cisplatin-induced neuropathic pain with DCUKA (50 mg/kg). In rats treated with the cancer chemotherapeutic agent cisplatin, cisplatin treatment lowers the organic pain threshold, and DCUKA treatment reverses this effect and increases the organic pain threshold to control levels. This data shows the ratio of organic pain thresholds after cisplatin treatment or cisplatin and DCUKA treatment to organic pain thresholds before cisplatin treatment. Figure 2 illustrates a comparison of the effectiveness of equimolar doses of DCUKA, BCUKA and gabapentin in reversing cisplatin-induced neuropathic pain, as measured by changes in organic pain thresholds. Figure 2 illustrates the reversal by DCUKA (50 mg/kg) of neuropathic pain induced by treatment with complete Freund's adjuvant (CFA). CFA treatment of rat paws induces inflammation and lowers organic pain threshold. DCUKA treatment reverses the decrease in organic pain thresholds in CFA-treated rats, returning thresholds to baseline levels. This data represents the ratio of organic pain threshold after CFA treatment or CFA and DCUKA treatment to organic pain threshold before CFA treatment. Figure 3 shows a comparison of the effects of DCUKA (50 mg/kg) and BCUKA (50 mg/kg) in reversing neuropathic pain induced by treatment of rats with CFA. This data represents the ratio of organic pain thresholds after CFA treatment or CFA and DCUKA or BCUKA treatment to baseline (pre-CFA) organic pain thresholds. Figure 2 shows the results of a meta-analysis of experiments determining the dose-dependent effect of DCUKA in reversing CFA-induced neuropathic pain. Figure 2 illustrates treatment of pain caused by diabetic neuropathy with DCUKA (50 mg/kg). Rats are treated with streptozotocin (STZ) to induce diabetes. Diabetes lowers organic pain threshold compared to baseline (pre-STZ treatment). DCUKA treatment reverses organic pain thresholds relative to baseline. This data shows the ratio of organic pain thresholds after STZ treatment or STZ and DCUKA treatment to pre-STZ organic pain thresholds. Figure 2 shows the results of a meta-analysis of experiments to determine the dose-dependent effect of DCUKA in reversing STZ-induced neuropathic pain. Figure 2 illustrates treatment of osteoarthritic pain with DCUKA. Rats were treated with monoiodoacetic acid (MIA), which initiates an inflammatory response. Cartilage damage and degradation results in chronic neuropathic pain, which is reflected as a lower organic pain threshold compared to baseline measured in animals not receiving MIA or drugs. DCUKA reversed organic pain thresholds in a dose-dependent manner. This data shows the ratio of organic pain thresholds after MIA treatment or MIA and DCUKA treatment to organic pain thresholds in animals receiving no MIA or drug. Figure 3 illustrates that administration of DCUKA enhances the ability of morphine to reverse CFA-induced neuropathic pain. Figure 3 illustrates that administration of DCUK-OEt increases the ability of morphine to reverse CFA-induced neuropathic pain. Figure 3 shows the results of an isobologram analysis demonstrating that DCUK-OEt significantly reduces the half-maximal effective dose required for morphine to reverse pain. We show that DCUKA enhances the ability of oxycodone to reverse CFA-induced neuropathic pain. We show that DCUKA enhances methadone's ability to reverse CFA-induced neuropathic pain. We show that DCUKA enhances the ability of tramadol to reverse MIA-induced osteoarthritic (neuropathic) pain. We show that DCUKA enhances aspirin's ability to reverse STZ-induced neuropathic pain (diabetic neuropathy). We show that DCUKA enhances the ability of diclofenac to reverse CFA-induced neuropathic pain. Figure 3 illustrates that administration of DCUKA after CFA injection prevents the development of CFA-induced neuropathic pain as measured by changes in organic pain threshold. Figure 2 illustrates that administration of DCUKA concurrently with the cancer chemotherapeutic agent cisplatin prevents the development of CFA-induced neuropathic pain as measured by changes in organic pain thresholds.

Detailed Description of Preferred Embodiments The analgesic compositions described herein are well suited for the treatment of chronic (neuropathic) pain syndromes.

The methods described herein provide a method for treating a subject (e.g., a human or veterinary patient) in need of pain relief with an opioid, a NE/5-HT reuptake inhibitor, and/or a non-steroidal anti-inflammatory drug (NSAID). treating with an aminoquinoline-containing composition that also includes.

Opioids suitable for use in the present analgesic compositions include opiates (i.e., naturally occurring plant alkaloids such as morphine, codeine, papaverine, thebaine, etc.); semi-synthetic opioids such as oxycodone, diamorphine, dihydrocodeine; Synthetic opioids, such as phenylpyridine derivatives, such as 6-amino-5-(2,3,5-trichlorophenyl)-pyridine-2-carboxylic acid methylamide; phenylpiperidine derivatives, such as fentanyl, sulfentanil, Examples include fentanyl, etc.; morphinan derivatives, such as levorphanol, butorphanol, etc.; diphenylheptane derivatives, such as methadone, propoxyphene, etc.; benzomorphan derivatives, such as pentazocine, fenazocine, etc.

Multi-targeted drugs suitable for use in analgesic compositions include drugs that act at opiate receptors and/or at monoamine reuptake transporters, such as tramadol.

NSAIDs suitable for use in analgesic compositions include aspirin, acetic acid derivatives (e.g., indomethacin, sulindac, etodolac, tolmetin, ketorolac, nabumetone, diclofenac, etc.), propionic acid derivatives (e.g., ibuprofen, naproxen, fenoprofen, etc.). , ketoprofen, flurbiprofen, oxaprozin, etc.), enolic acid derivatives (e.g., piroxicam, meloxicam, tenoxicam, etc.), fenamic acid derivatives (e.g., mefenamic acid, meclofenamic acid, flufenamic acid, etc.), as well as the pharmaceutically acceptable compounds listed above. Examples of salts include:

Examples of NSAID salts suitable for use in the present compositions include pharmaceutically acceptable salts of the acetic acid derivatives described above, such as indomethacin salts (e.g., indomethacin sodium, indomethacin meglumine, etc.), tolmetin salts (e.g., tolmetacin ), ketorolac salts (e.g., ketorolac tromethamine, etc.), diclofenac salts (e.g., diclofenac sodium, diclofenac diethylamine, diclofenac epolamine, etc.), as well as pharmaceutically acceptable salts of the propionic acid derivatives described above, e.g. These include ibuprofen salts (eg, ibuprofen lysine, ibuprofen methylglucamine, etc.), naproxen salts (eg, naproxen piperazine, naproxen sodium, etc.), and fenoprofen salts (eg, fenoprofen calcium, etc.).

Aminoquinoline compounds of formulas (I), (II), (III), (IV), (V) and (VI) may be prepared by any conventional method known to those skilled in the art. For example, U.S. Pat. No. 6,962,930 to Tabakoff et al. and U.S. Pat. No. 7,923,458 to Tabakoff (incorporated by reference in their entirety) describe certain quinoline compounds similar to those of the present invention. The preparation of analogs is described, which is easily applicable to the preparation of desired aminoquinoline compounds. Scheme 1 provides a general scheme for preparing aminoquinoline compounds of formula (I) and structurally related or analog compounds from 4-amino-substituted quinoline compounds (A), where the R substituent is the same as in formula (I). The amino group of compound (A) reacts with an activated acylated compound (B) containing a leaving group (LG) that is reactive with aromatic amino groups to form a compound of formula (I). Form. Substituted quinoline compounds having an amino group in the 4-position of the quinoline ring system, such as compounds (A) with various substitution patterns in the quinoline ring system, and their preparation are well known to those skilled in the chemical arts. For example, Protective Groups in Organic Synthesis, 3rd edition, edited by Green and Wuts, John Wiley & Sons, Inc. (1999) (incorporated herein by reference) may be used in the preparation of compound (A), compound (B), and/or in the coupling of compound (A) and compound (B). may be used as necessary or desired to facilitate the preparation and/or isolation of compounds of formula (I).

Scheme 1.

As used herein, the term "aminoquinoline compound" refers to compounds of formulas (I), (II), (III), (IV), (V) and (VI) as described herein. Refers to the compound shown in Aminoquinoline compounds are useful for chronic pain and a variety of other conditions.

The term "alkyl," as used herein, is straight, branched, or cyclic ("cycloalkyl") and unsubstituted or substituted (i.e., its refers to a saturated hydrocarbon group (of the formula C _n H _2n+1 ) in which one or more hydrogens are replaced by another atom or a branch.

"Aryl" refers to either a 6-carbon benzene ring or a fused 6-carbon ring of other aromatic derivatives (e.g., Hawley's Condensed Chemical Dictionary (13th edition), R. J. Lewis, ed., J. .Wiley & Sons, Inc., New York (1997)). Aryl groups include, without limitation, phenyl and naphthyl.

A "heteroaryl" ring contains at least one carbon atom in the ring, and one or more atoms, typically 1 to 4, that form the ring are atoms other than carbon atoms, i.e., heteroatoms. (typically O, N or S). Heteroaryls include, without limitation, morpholinyl, piperazinyl, piperidinyl, pyridyl, pyrrolidinyl, pyrimidinyl, triazinyl, furanyl, quinolinyl, isoquinolinyl, thienyl, imidazolinyl, thiazolyl, indolyl, pyrrolyl, oxazolyl, benzofuranyl, benzothienyl. , benzothiazolyl, benzoxazolyl, isoxazolyl, triazolyl, tetrazolyl, indazolyl, indolinyl, indolyl-4,7-dione, 1,2-dialkyl-indolyl, 1,2-dimethyl-indolyl, and 1,2-dialkyl-indolyl -4,7-dione is mentioned.

"Alkoxy" means -OR, where R is alkyl as defined above, eg, methoxy, ethoxy, propoxy, 2-propoxy, and the like.

"Alkenyl" means a linear monovalent hydrocarbon radical of 2 to 6 carbon atoms or a branched monovalent hydrocarbon radical of 3 to 6 carbon atoms containing at least one double bond (e.g. , ethenyl, propenyl, etc.).

"Alkynyl" means a linear monovalent hydrocarbon radical of 2 to 6 carbon atoms or a branched divalent hydrocarbon radical of 3 to 6 carbon atoms containing at least one triple bond (e.g. ethynyl, propynyl, etc.).

"Halide" and "halo" refer to halogen atoms including fluorine, chlorine, bromine and iodine.

Classification of substituents is known, for example, C _1-6 alkyl, and here includes each of its individual substituent members, for example C ₁ alkyl, C ₂ alkyl, C ₃ alkyl and C ₄ alkyl. Say something.

"Substituted" means that one or more hydrogen atoms on the indicated atom are replaced with one selected from the indicated group, except that the normal valence of the indicated atom and this substitution results in a stable compound.

An "unsubstituted" atom has all the hydrogen atoms supported by its valence. When a substituent is, for example, "keto", the two hydrogens on this atom are replaced. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds; a "stable compound" or "stable structure" refers to a combination of substituents and/or variables that results in a stable compound; It refers to a compound that is sufficiently robust to withstand isolation to a certain degree of purity and formulation into an effective therapeutic agent.

"Pharmaceutically acceptable" when used in reference to a salt or carrier refers to a substance that is generally accepted as suitable for administration to or contact with the human body or parts thereof. say. Pharmaceutically acceptable salts are substances in which the parent compound (e.g., an aminoquinoline compound of formula (I)) or some other therapeutic agent or excipient has been modified by producing an acid or salt thereof. be. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues (e.g., amines), or alkaline or organic salts of acidic residues (e.g., carboxylic acids). can be mentioned. Pharmaceutically acceptable salts include, for example, conventional non-toxic salts or quaternary ammonium salts of the parent compound formed from non-toxic inorganic or organic acids. Such conventional non-toxic salts include those derived from inorganic acids (e.g., hydrochlorides, hydrobromides, sulfates, sulfamates, phosphates, nitrates, etc.); as well as those prepared from organic acids. (e.g. acetate, propionate, succinate, glycolate, stearate, lactate, malate, tartrate, citrate, ascorbate, pamoate, maleate) , hydroxymaleate, phenylacetate, glutamate, benzoate, salicylate, sulfanilate, 2-acetoxybenzoate, fumarate, toluenesulfonate, methanesulfonate, ethanedisulfonate, oxalate, isethionate, etc.). Pharmaceutically acceptable salts are suitable for use in contact with human and animal tissues, have a good profit and loss ratio, without undue toxicity, irritation, allergic reactions or other problems or complications. These forms of compounds.

Pharmaceutically acceptable salt forms of the aminoquinoline compounds provided herein are synthesized by conventional chemical methods from a parent compound containing a basic or acidic moiety. Generally, such salts are prepared, for example, by reacting the free acid or free base form of these compounds with a stoichiometric amount of a suitable base or acid in water or in an organic solvent or in a mixture thereof. prepared. Generally, non-aqueous media such as ether, ethyl acetate, ethanol, isopropanol or acetonitrile are preferred. A list of suitable salts can be found in Remington's Pharmaceutical Sciences, 17th Edition, Mack Publishing Company, Easton, Pa. , 1985, p. No. 1418, the disclosure of which is incorporated herein by reference.

A "prodrug" is any covalently bound carrier that releases the active parent drug of an aminoquinoline compound in vivo when such prodrug is administered to a mammalian subject. Prodrugs of the aminoquinoline compounds of the present invention modify a functional group present in the compound that is cleaved to the parent compound either by conventional manipulation or in vivo, including enzymatic conversion. Prepared by. As a prodrug, a hydroxy group, an amine group, or a sulfhydryl group may be attached to any group which, when administered to a mammalian subject, cleaves to form a free hydroxyl group, amino group, or sulfhydryl group, respectively. Compounds may be mentioned. Examples or prodrugs include, but are not limited to, acetate, formate, and benzoate derivatives of the alcohol and amine functional groups in the aminoquinoline compounds of the invention. Compounds that function effectively as prodrugs of the aminoquinoline compounds of the invention can be identified using conventional techniques known in the art. Examples of such prodrug derivatives can be found in, for example, (a) Design of Prodrug edited by H. Bundgaard, (Elsevier, 1985) and Methods in Enzymology, Vol. 42, p. 309-396, edited by K. Widder et al. (Academic Press, 1985); (b) A Textbook of Drug Design and Development, edited by Krogsgaard-Larsen and H. Bundgaard, Chapter 5 “Design and Application of Prodrug,” by H. Bundgaard p. 113-191 (1991); (c) H. Bundgaard, Advanced Drug Delivery Reviews, 8, 1-38 (1992); (d) H. Bundgaard et al., Journal of Pharmaceutical Sciences, 77:285 (1988); Kakeya et al., Chem. Pharm. Bull. , 32:692 (1984), each of which is incorporated herein by reference.

Additionally, the present invention also includes solvates, metabolites, and pharmaceutically acceptable salts of the aminoquinoline compounds.

The term "solvate" refers to an aggregate of a molecule with one or more solvent molecules. A "metabolite" is a pharmacologically active product of a particular compound or a salt thereof that is produced in the body through in vivo metabolism. Such products may result, for example, from oxidation, reduction, hydrolysis, amidation, deamidation, esterification, deesterification, enzymatic cleavage, etc. of the administered compound. Accordingly, the present invention includes metabolites of aminoquinoline compounds, including compounds produced by a process that involves contacting a mammal with a compound of the present invention for a sufficient period of time to produce a metabolite thereof.

Pharmaceutical compositions and treatment regimens.
In one aspect, the invention provides a pharmaceutically effective amount of an aminoquinoline compound along with an opioid or NSAID in a pharmaceutically acceptable carrier (e.g., diluent, complexing agent, additive, excipient, adjuvant, etc.). A pharmaceutical composition is provided. The aminoquinoline composition may exist, for example, in salt form, microcrystalline form, nanocrystalline form, nanoparticle form, microparticle form, and/or amorphous form. The carrier may be an organic or inorganic carrier suitable for topical, enteral or parenteral administration. The aminoquinoline compositions of the invention can be prepared, for example, in pills, pellets, capsules, liposomes, suppositories, nasal sprays, solutions, emulsions, suspensions, etc. using conventional non-toxic, pharmaceutically acceptable carriers. The compositions may be formulated as agents, aerosols, targeted chemical delivery systems, or any other form well known in the pharmaceutical formulation art suitable for such use. Non-limiting examples of carriers that may be used include water, glucose, lactose, gum acacia, gelatin, mannitol, starch paste, magnesium trisilicate, talc, cornstarch, keratin, colloidal silica, potato starch, urea, and Other carriers suitable for producing the formulation in solid, semisolid, liquid or aerosol form may be mentioned. Additionally, auxiliaries, stabilizers, thickeners and colorants and perfumes may be used.

The pharmaceutical composition comprises at least one aminoquinoline compound described herein in combination with an opioid, NE- or 5HT uptake inhibitor and/or NSAID and a pharmaceutically acceptable carrier, vehicle, or physiologically acceptable carrier. including in combination with diluents such as aqueous buffers at a pH of 7 to 8.5, polymer-based nanoparticle vehicles, liposomes, and the like. The pharmaceutical composition may be delivered in any suitable dosage form, such as a liquid, gel, solid, cream, or paste dosage form. In one embodiment, the composition may be applied to obtain sustained release of the aminoquinoline compound.

In some embodiments, the pharmaceutical composition includes, but is not limited to, oral, rectal, intranasal, topical (including buccal and sublingual), transdermal, intravaginal, parenteral (intramuscular, intraperitoneal) Suitable forms for administration include intravenous, subcutaneous, and intravenous), spinal (epidural, intrathecal), and central (intraventricular) administration. The compositions may, where appropriate, be conveniently presented in separate dosage units. Pharmaceutical compositions of the invention may be prepared by any method well known in the pharmaceutical art. Some preferred modes of administration include intravenous (iv), topical, subcutaneous, oral and spinal. For systemic administration, the aminoquinoline compound will generally be administered to a subject at a dosage ranging from about 1 milligram per kilogram of body weight (mg/kg) to about 200 mg/kg of the aminoquinoline compound. Dew. Typically, the dosage administered should be sufficient to provide a concentration of the aminoquinoline compound in the subject from about 100 nanomolar (nM) to about 100 micromolar (mM).

Pharmaceutical compositions suitable for oral administration include capsules, cachets, or tablets, each containing a predetermined amount of one or more aminoquinoline compounds as powders or granules. In another embodiment, the oral composition is a solution, suspension, or emulsion. Alternatively, the aminoquinoline compound containing analgesic composition may be administered as a bolus, lozenge or paste. Tablets and capsules for oral administration may contain conventional excipients such as binders, fillers, lubricants, disintegrants, colorants, flavoring agents, preservatives, or wetting agents. Tablets may be coated, if desired, according to methods well known in the art. Oral liquid preparations include, for example, aqueous or oily suspensions, solutions, emulsions, syrups, or elixirs. Alternatively, the compositions may be presented as a dry formulation for constitution with water or another suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, emulsifying agents, non-aqueous vehicles (which may include edible oils), preservatives, and the like. Typically, additives, excipients, etc. are included in compositions for oral administration in concentration ranges that are suitable for their intended use or function in the composition and are well known in the pharmaceutical formulation art. ,included.

Pharmaceutical compositions for parenteral, spinal, or central administration (e.g., by bolus injection or continuous infusion) are preferably provided in ampoules, prefilled syringes, small volume infusions, or multidose containers with added storage. It may also be provided in unit dosage form, including: Compositions for parenteral administration may be suspensions, solutions, or emulsions and may contain excipients such as suspending, stabilizing, and dispersing agents. Typically, additives, excipients, etc., are present in compositions for parenteral administration within a concentration range suitable for its intended use or function in the composition and well known in the pharmaceutical formulation art. And included. The aminoquinoline compound is included in the composition within a therapeutically useful and effective concentration range as determined by conventional methods well known in the medical and pharmaceutical arts.

Pharmaceutical compositions for topical administration to the epidermis (mucosal or dermal surfaces) may be formulated as ointments, creams, lotions, gels, or transdermal patches. Such transdermal patches may include penetration enhancers such as, for example, linalool, carvacrol, thymol, citral, menthol, t-anethole. Ointments and creams may, for example, contain an aqueous or oily base with the addition of suitable thickening agents, gelling agents, coloring agents, and the like. Lotions and creams contain an aqueous or oily base and typically also contain one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents, thickening agents, coloring agents, and the like. Gels preferably include an aqueous carrier base and include gelling agents such as crosslinked polyacrylic acid polymers, derivatized polysaccharides (eg, carboxymethylcellulose), and the like. Typically, additives, excipients, etc., are included in compositions for topical administration in concentration ranges suitable for their intended use or function in the composition and well known in the pharmaceutical formulation art. , will be included.

Pharmaceutical composition dosage forms suitable for buccal or sublingual administration include lozenges containing the analgesic in a flavored base (e.g., sucrose, acacia, or tragacanth); , gelatin and glycerin or sucrose and acacia); and mouthwashes containing the active ingredients in a suitable liquid carrier. Pharmaceutical composition dosage forms for topical administration may include penetration enhancers, if desired. Typically, additives, excipients, etc., are present in compositions for topical oral administration within a concentration range suitable for its intended use or function in the composition and well known in the pharmaceutical formulation art. And included. The analgesic agent is included in the composition within a therapeutically useful and effective concentration range as determined by conventional methods well known in the medical and pharmaceutical arts.

For rectal administration, the analgesic is provided in a solid or semisolid (eg, cream or paste) carrier or vehicle. For example, such rectal compositions may be presented as unit dose suppositories. Suitable carriers or vehicles include cocoa butter and other materials commonly used in the art. Typically, additives, excipients, etc., are included in compositions for rectal administration in concentration ranges suitable for their intended use or function in the composition and well known in the pharmaceutical formulation art. , will be included.

Analgesic compositions of the invention suitable for intravaginal administration are provided as pessaries, tampons, creams, gels, pastes, foams or sprays containing the aminoquinolines of the invention in combination with carriers known in the art. Alternatively, compositions suitable for intravaginal administration may be delivered in liquid or solid dosage forms. Typically, additives, excipients, etc., are present in compositions for intravaginal administration within a concentration range suitable for its intended use or function in the composition and well known in the pharmaceutical formulation art. And it will be included.

Also included in the invention are analgesic compositions suitable for intranasal administration. Such intranasal compositions include, in addition to the analgesic, a delivery vehicle and a device suitable for delivery, including a liquid spray, dispersible powder or drops. Drops may be formulated with an aqueous or non-aqueous base that also includes one or more dispersing agents, solubilizing agents, or suspending agents. Liquid sprays are conveniently delivered from pressurized packs, syringes, nebulizers, or other convenient means of delivering aerosols containing aminoquinolines. The pressurized pack contains a suitable propellant such as dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide, or other suitable gas known in the art. Alternatively, pharmaceutical compositions for administration by inhalation or insufflation may be controlled by a valve provided to deliver a measured amount. Such powder compositions may be provided, for example, in the form of capsules, cartridges, gelatin packs or blister packs (in which the powder may be placed with the aid of an inhaler or insufflator). Typically, additives, excipients, etc., are present in compositions for intranasal administration, such as for intranasal administration. Concentration ranges suitable for the purpose or function and well known in the pharmaceutical formulation art will be included.

A method of alleviating chronic pain (e.g., neuropathic pain) includes administering an effective amount of an aminoquinoline compound to a patient suffering from one of the conditions mentioned above, including an opioid and/or an NSAID and/or a 5-HT/ including co-administration with a NE uptake inhibitor. Preferably, the analgesic composition is administered parenterally or enterally. Dosing of an effective amount of an aminoquinoline compound may vary depending on the age and condition of the individual patient being treated. Suitable dosages of aminoquinoline compounds typically range from about 1 mg/kg to about 200 mg/kg; from one-tenth to the full recommended dose of a particular compound). Such dosage forms may be administered one or more times per day, one or more times per week, one or more times per month, etc.

As used herein, the terms "mitigate", "inhibit", "block", "prevent", "alleviating", "relieving", and "antagonist" ", when referring to a composition, indicates that the compound is capable of improving the onset, severity, size, volume or related symptoms of at least about 7.5%, 10%, 12.5%, 15%, 17.5%, 20%, 22.5%, 25%, 27.5%, 30 %, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 90%, or 100%. The terms "increase," "raise," "enhance," "upregulate," "improve," "activate," and "agonist" when referring to a compound have no application to the present composition. The compound reduces the onset, severity, magnitude, volume or related symptoms of a symptom, event or activity by at least about 7.5%, 10% compared to the symptoms, events or activities normally present in , 12.5%, 15%, 17.5%, 20%, 22.5%, 25%, 27.5%, 30%, 35%, 40%, 45%, 50%, 55%, 60% , 65%, 70%, 75%, 80%, 90%, 100%, 150%, 200%, 250%, 300%, 400%, 500%, 750%, or 1000%.

The following examples are included to demonstrate certain aspects of the invention. It is understood that the techniques disclosed within this example (representative of techniques known to work satisfactorily in practicing the invention) may be considered to constitute preferred embodiments for the practice thereof. , should be understood by those skilled in the art. However, those skilled in the art will appreciate that, in view of this disclosure, many changes can be made in the specific embodiments disclosed and still obtain similar or similar results without departing from the spirit and scope of the invention. should be understood. This example is provided for illustrative purposes only and is not intended to be limiting.

How to confirm reinforcement/synergy.

Although the definition of potentiation/synergism in drug effects is relatively simple, approaches to demonstrating synergism are not necessarily set in stone. A methodological review by Foucquier and Gued (2015) highlights analytical approaches for measuring the efficacy of drug combinations and presents a concise description of currently used methods. This method is classified as an "effect-based strategy" consisting of four approaches: (1) subthreshold combinations; (2) best single-agent approaches; (3) chemotactic responses and (4) Bliss independence. models; as well as the “dose-effect based strategy” first described by Loewe (1926) and now called isobologram analysis (Tallarida 2001). Within this "effect-based strategy," all four approaches are utilized to test for potentiation/synergism with the described drug combinations. All four approaches presented consistent results.

Use of DCUKA to Increase the Efficacy of Opioids/NSAIDs/5-HT and NE Reuptake Inhibitors The following data show that doses of DCUKA that are equivalent to threshold doses for reducing chronic pain Administration in a rat model (Freund's adjuvant model) or a rat model of osteoarthritis (MIA) with low doses of opioids, NSAIDs or compounds that reduce pain by inhibiting synaptic uptake of norepinephrine and/or serotonin (e.g. tramadol) When used, it has been shown to increase the efficacy of opioids, NSAIDs and/or serotonin/norepinephrine reuptake inhibitors in alleviating chronic pain. For opioids other than morphine, the ``morphine equivalent dose scale'' or ``morphine milligram equivalent (MME)'' standard is used to ascertain the amount of another analgesic that is equivalent to a particular daily dose of morphine. obtain. Administration of DCUKA, or DCUK-OEt (acting as a prodrug for DCUKA), with morphine increases the potency of morphine by 4-5 times. Using the MME to calculate the dose of another analgesic given on a daily dose basis (the dose and number of times this dose is administered per day of the analgesic in question), DCUKA or DCUK for pain treatment - Addition of OEt allows reduction of analgesic dose in the same manner as reduction of morphine dose when morphine is given with DCUKA/DCUK-OEt.

Calculation of the dose of analgesic given when DCUKA or DCUK-OEt is used to enhance analgesia.

The dose of another analgesic when given with DCUKA may be calculated by the following formula:
Opioid analgesic dose = Daily dose of morphine used in similar situations ÷ MME ÷ DCUKA or DCUK - As a result of the addition of OEt A multiple based on the increase in opioid potency As an example, to calculate the dose of oxycodone: The following information is used: (1) The MME for the opioid of interest (oxycodone in this case) is 1.5 (Von Korff et al., Clin. J. Pain 24(6):521-527 (2008 )); (2) the daily dose of morphine required to treat the level of pain reported by the patient. The use of rating scales is important in this regard (Schneider et al., 2003). For moderate to severe pain, a single dose of morphine (oral) can vary between 10 and 30 mg, with such doses taken six times a day (i.e., 60 to 180 mg/day). ); (3) the fold by which the dose of an opioid can be reduced by adding DCUKA to a dosing regimen for pain.

For humans, the dose of DCUKA can vary between 150 and 450 mg given two to three times a day. When DCUKA is administered in this manner, the dose of opioid used may be reduced by a factor of 4-5 (this multiple is determined based on the data in Figures 11 and 12). The pain treatment specialist must closely monitor the patient in order to prepare the necessary dosage for patient comfort. This can be accomplished by increasing the dose of the opioid or DCUKA within the recommended range.

Example of actual dose calculation

Oxycodone/day starting dose = (60 mg [morphine daily starting dose]) ÷ (1.5 [MME]) ÷ (5 = Opioid reduction factor) = 8 mg/day methadone/day starting dose = (60) ÷ (4 )÷(5)=3mg/day.
Methadone given to control pain is usually titrated upward over a six week period. Dose reductions given with DCUKA can be similarly titrated.

Similar calculations can be made for other opioids approved for use in humans for the treatment of chronic pain syndromes. It should be clear to those skilled in the art that there are significant differences between individuals in the amount of pain perceived, and that perceived pain can also vary depending on the cause of the pain and the extent of the injury. be. This example is illustrative of how to reduce the dose of opioid in conjunction with the administration of DCUKA can be considered while maintaining the level of analgesia/anthyperalgesia. If further control of pain is needed, the daily dose of DCUKA and/or opioid may be increased gradually (increases include 25-50% in the daily dose of DCUKA or opioid).

For use of NSAIDs with DCUKA, the same principles apply, except that the fold by which the dose of the NSAID can be reduced when given with DCUKA is within the range of about 5 to about 6.

Diclofenac daily dose = (60 mg [morphine daily dose]) ÷ (0.10) ÷ (6) = 100 mg
For humans receiving diclofenac sodium, the recommendation is not to exceed 225 mg/day.

Therefore, based on the discovery that DCUKA and its prodrug (DCUK-OEt) can increase the efficacy of opioids and NSAIDs, downward modification of daily doses of opioids and NSAIDs results in decreased side effects while maintaining pain relief. .

In the absence of published MEE values for NE/5-HT reuptake inhibitors, we present a You can use the data you have. Tramadol is a weakening opioid but has been shown to have substantial effects as a NE/5-HT reuptake inhibitor (Barber, 2011). Other NE/5-HT reuptake inhibitors include duloxetine, venlafaxine, milnacipran, and others. This data shows that the dose of NE/5-HT reuptake inhibitor can be halved when given to humans with 150-450 mg DCUKA in 2-3 doses/day.

Example 1. Preparation of compounds of formula (VI) Derivatives of kynurenic acid containing a tertiary ureido group, including 5,7-dichloro-4-(3,3-diphenylureido)quinoline-2-carboxylic acid (DCUKA, 7a) , may be synthesized as previously described (Snell et al., 2000) through the use of reactive carbamoyl chloride intermediates (6a-b). However, improvements can be achieved in this synthesis due to simultaneous ester hydrolysis during the final acylation reaction. One compound embodiment, 5,7-dichloro-4-(3,3-dibutylureido)quinoline-2-carboxylic acid (BCUKA, 7b), is synthesized through synthetic steps I through as described and illustrated in Scheme 2. IV, synthesized via this method (reagents and conditions (I): MeOH, reflux, 16 h. (II): Ph ₂ O, 250 °C, 2 h. (III): (a) ClSO ₂ NCO, MeCN, Reflux, 2 h. (b) HCl, MeOH, RT, 30 min. (IV): NaH, DMF, 0° C. to RT, 16 h).

Scheme 2.

Synthesis step I.
3,5-dichloroaniline (1, 5.00 g, 30.9 mmol) and dimethylacetylene dicarboxylate (2, 3.80 ml, 30.9 mmol) were combined in anhydrous MeOH (60 ml) under nitrogen and Refluxed for 16 hours. The reaction mixture was cooled to room temperature and evaporated to dryness. The resulting yellow solid was recrystallized (twice) from MeOH to yield a mixture of cis and trans isomers of the target dimethylanilinomaleate (3) as light yellow crystals (5.23 g, 17.2 mmol ). The absorption peak values (ppm) found in the ¹ H NMR spectrum conducted in deuterated DMSO are 3.57 & 3.67 (3H, s), 3.72 & 3.80 (3H, s), 5.35 & 5.58. (1H, s), 6.98 & 7.12 (2H, s _app ), 7.23 & 7.31 (1H, s _app ), 9.52 & 9.64 (1H, br, s).

Synthesis step II.
Dimethylanilinomaleate (3, 3.50 g, 11.5 mmol) was added portionwise to diphenyl ether (70 ml) at 250°C. The temperature of the resulting solution was maintained at 250°C for 2 hours, then cooled to room temperature and diluted with hexane (100ml). The resulting precipitate was removed by filtration, washed with hexane (50 ml) and suspended in refluxing ethanol before filtering off soluble impurities. The filtered solid was dried under vacuum to yield the desired quinolone carboxylate (4) as an off-white solid (3.10 g, 11.4 mmol). The absorption peak values (ppm) found in the ¹ H NMR spectrum conducted in deuterated DMSO are 3.96 (3H, s), 6.59 (1H, s), 7.42 (1H, s), They were 7.97 (1H, s) and 12.05 (1H, br). This process can be adapted to be used with a continuous flow device (Cao, 2017) to run against elevated temperatures in the presence of diphenyl ether.

Synthesis step III.
Chlorosulfonyl isocyanate (1.20 ml, 13.8 mmol) was added to a slurry of quinoline carboxylate (4, 2.50 g, 9.19 mmol) in anhydrous MeCN (35 ml) at room temperature. The mixture was brought to reflux for 1.5 hours at which point heating was removed and a 1.0M solution of HCl in anhydrous MeOH (20ml) was added. The reaction mixture was cooled to room temperature with stirring until a precipitate formed after 1 hour. The precipitate was filtered off, washed with MeCN, and air dried. The filter cake was suspended in water (50 ml) to which saturated sodium carbonate solution (approx. 5 ml) was added to pH 10 to increase the viscosity of the suspension. The resulting solid was collected by filtration, washed with cold water, and dried under vacuum (40° C.) to yield the target aminoquinoline (5) as an off-white solid (1.82 g, 6.71 mmol). . The absorption peak values (ppm) found in the ¹ H NMR spectrum conducted in deuterated DMSO are p4.05 (3H, s), 6.04 (2H, s), 7.33 (1H, s), They were 7.47 (1H, d, J = 1.9Hz) and 8.10 (1H, d, J = 1.9Hz).

Synthesis step IV.
Acylation and simultaneous ester hydrolysis of aminoquinoline (5) to yield 5,7-dichloro-4-(3,3-dibutylureido)quinoline-2-carboxylic acid (BCUKA, 7b) was carried out as follows. N,N-dibutylcarbamoyl chloride (6b, 96 mg, 0.50 mmol) and aminoquinoline (5, 113 mg, 0.42 mmol) were dissolved in anhydrous DMF (2 ml) and cooled to 0°C. A dispersion of sodium hydride in mineral oil (60%, 35 mg, 0.83 mmol) was added and the mixture was warmed to room temperature and stirred for 16 hours. The reaction was quenched by addition to saturated NH ₄ Cl solution (1 ml) and then adjusted to pH 3 with 1.0 M HCl aqueous solution. Extraction with EtOAc (2x10ml) followed by washing with saturated brine (5ml) and drying ( _{Na2SO4 )} gave the crude product as a pale yellow oil. Compound purification via silica gel chromatography (9:1 DCM:MeOH) produced 5,7-dichloro-4-(3,3-dibutylureido)quinoline-2-carboxylic acid (DBCUKA, 7b) as a pale yellow solid. (82 mg, 0.20 mmol). The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in CDCl ₃ are 1.00 (6H, t, J = 7.4 Hz), 1.36-1.45 (4H, m), 1 .64-1.72 (4H, m), 3.39-3.45 (4H, m), 5.17 (1H, s), 7.69 (1H, s), 8.30 (1H, s ), 9.16 (1H, s).

Carbamoyl chlorides have limited availability on the market and are, moreover, characterized by particularly high reactivity (in particular towards hydrolysis) and subsequent low stability. This is particularly evident in the case of mono-n-substituted carbamoyl chlorides. Therefore, it would be beneficial to utilize alternative, less reactive carbamoyl cation equivalents to prepare mono-n-substituted analogs of kynurenic acid. Carbamoylimidazoles (e.g. 9a-d) have been shown to be suitable reactive species for the synthesis of a variety of functional groups including ureas, thioureas, carbamates, thiocarbamates and amides ( Grzyb et al., 2005). Derivatives of kynurenic acid containing secondary ureido groups were prepared using this approach in synthetic steps V-VII described and illustrated in Scheme 3 (Reagents and conditions: (V): CDI, DCM, 0°C - RT, 16 h. (VI): 5, NaH, DMF, 0°C - RT, 16 h. (VII) TFA, DCM, RT, 16 h.).

Scheme 3.

General example of synthesis step V.
n-Butylamine (8a, 100 μl, 74 mg, 1.01 mmol) in DCM (1 ml) was added to a solution of CDI (0.197 g, 1.21 mmol) in DCM (5 ml) at 0°C, then the reaction mixture was warmed to RT and mixed overnight. The solution was diluted with DCM (10 ml), washed with water (2 x 10 ml) and brine (10 ml), dried (Na ₂ SO ₄ ) and evaporated to dryness to give the target carbamoylimidazole (9a) as a colorless Obtained as an oil (115 mg, 0.69 mmol). The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in CDCl ₃ are 0.97 (3H, t, J = 7.4 Hz), 1.42 (2H, qt, J = 7.6, 7.3Hz), 1.63 (2H, tt, J = 7.3, 7.0Hz), 3.44 (2H, dt, J = 7.0, 6.7Hz), 6.75 (1H, br ), 7.07 (1H, s), 7.42 (1H, s), and 8.17 (1H, s).

N-(3-(dimethylamino)propyl)-1H-imidazole-1-carboxamide (9b) was prepared from 3-dimethylaminopropylamine (8b) as described in Synthesis Step V. The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in CDCl ₃ are 1.77 (2H, tt, J = 5.7, 5.5 Hz), 2.32 (6H, s), 2 .56 (2H, t, J = 5.5Hz), 3.54 (2H, dt, J = 5.9, 5.5Hz), 7.07 (1H, s), 7.27 (1H, s) , 8.04 (1H, s), 9.34 (1H, br).

tert-Butyl (3-(1H-imidazole-1-carboxamido)propyl) carbamate (9c) was prepared from tert-butyl (3-aminopropyl) carbamate (8c) as described in Synthesis Step V. The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in CDCl ₃ are 1.49 (9H, s), 1.73 (2H, tt, J = 5.8, 5.7 Hz), 3 .30 (2H, dt, J = 6.4, 5.7Hz), 3.48 (2H, dt, J = 6.0, 5.8Hz), 4.91 (1H, br), 7.11 ( 1H, s), 7.52 (1H, s), 7.92 (1H, br), and 8.25 (1H, s).

Synthesis step of tert-butyl (3-(1H-imidazole-1-carboxamido)propyl) (methyl) carbamate (9d) from N-(3-aminopropyl)-N-methylcarbamic acid tert-butyl ester (8d) Prepared as described in V. The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in CDCl ₃ are 1.49 (9H, s), 1.74-1.80 (2H, br), 2.87 (3H, s). ), 3.35-3.43 (4H, m), 7.09 (1H, s), 7.53 (1H, s), 8.11 (1H, br), 8.25 (1H, s) Met.

General example of synthesis step VI.
In a manner analogous to the carbamoyl chloride in synthesis step IV, the use of carbamoylimidazoles (9a-d) may enable one step involving acylation of the aminoquinoline (5) and simultaneous ester hydrolysis. This approach is used for the synthesis of 4-(3-butylureido)-5,7-dichloroquinoline-2-carboxylic acid (10a) as follows; N-butyl-1H-imidazole-1 -Carboxamide (9a, 125 mg, 0.95 mmol) and aminoquinoline (5, 215 mg, 0.79 mmol) were dissolved in anhydrous DMF (4 ml) and cooled to 0°C. A dispersion of sodium hydroxide in mineral oil (60%, 63 mg, 1.58 mmol) was added and the mixture was allowed to warm to room temperature and stirred for 16 hours. The reaction was quenched via the addition of saturated NH ₄ Cl solution (3 ml) and then adjusted to pH 3 using 1.0 M aqueous HCl. After extraction with EtOAc (2x20ml), washing with saturated brine (10ml) and _drying ( _Na2SO4 ) gave the crude product as a pale orange residue. Compound purification via reverse phase (C18) silica gel chromatography (1:1 H ₂ O:MeCN) yielded 4-(3-butylureido)-5,7-dichloroquinoline-2-carboxylic acid (10a), Obtained as a beige solid (142 mg, 0.39 mmol). The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in deuterated DMSO are 0.92 (3H, t, J = 7.3 Hz), 1.31-1.38 (2H, m ), 1.44-1.52 (2H, m), 3.16 (2H, dt, J = 6.6, 6.0Hz), 7.47 (1H, br), 7.87 (1H, d , J=2.2Hz), 8.11 (1H, d, J=2.2Hz), 8.68 (1H, s), and 9.12 (1H, br).

5,7-dichloro-4-(3-(3-(dimethylamino)propyl)ureido)quinoline-2-carboxylic acid (10b) was converted into N-(3-(dimethylamino)propyl)-1H-imidazole-1 - prepared from carboxamide (9b) as described in Synthesis Step VI. Due to the zwitterionic nature of the target compound, acidification to pH 1/2 was carried out with TFA followed by reverse phase (C18) chromatography to obtain the product in the TFA salt form. The absorption peak values (ppm) found in the ¹ H NMR spectrum conducted in D ₂ O are 1.87-2.00 (2H, m), 2.87 (6H, s), 3.12-3. 20 (2H, m), 3.21-3.31 (2H, m), 7.13 (1H, s), 7.48 (1H, s), 8.06 (1H, s). The absorption peak value (ppm) found in the ¹⁹ F NMR spectrum performed in D ₂ O was −75.6.

4-(3-(3-((tert-butoxycarbonyl)amino)propyl)ureido)-5,7-dichloroquinoline-2-carboxylic acid (10c) was converted into tert-butyl (3-(1H-imidazole-1 -carboxamido)propyl)carbamate (9c) as described in Synthesis Step VI. The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in deuterated DMSO are 1.39 (9H, s), 1.60 (2H, tt, J = 6.8, 6.6Hz) , 2.95-3.02 (2H, m), 3.12-3.18 (2H, m), 6.83 (1H, br), 7.45 (1H, br), 7.85 (1H , s), 8.10 (1H, s), 8.65 (1H, s), and 9.15 (1H, br).

4-(3-(3-((tert-butoxycarbonyl)(methyl)amino)propyl)ureido)-5,7-dichloroquinoline-2-carboxylic acid (10e) was converted to tert-butyl Prepared from imidazole-1-carboxamido)propyl)methylcarbamate (9d) as described in Synthesis Step VI. The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in deuterated DMSO are 1.39 (9H, s), 1.63-1.71 (2H, m), 2.79 (3H , s), 3.08-3.16 (2H, m), 3.19-3.26 (2H, m), 7.27 (1H, br), 7.68 (1H, d, J = 1 .8Hz), 8.29 (1H, d, J=1.8Hz), 8.40 (1H, br), and 8.97 (1H, br).

General example of synthesis step VII.
TFA (173 μL, 2.25 mmol) was added to a solution of Boc-protected amine (10c, 103 mg, 0.23 mmol) in DCM (4 ml). After stirring at room temperature for 16 hours, the solvent was removed under reduced pressure and the residue was purified directly by reverse phase chromatography (C18, 1:1 H ₂ O:MeCN) to give 4-(3-(3-amino) The TFA salt form of propyl)ureido)-5,7-dichloroquinoline-2-carboxylic acid (10d) was obtained as a white solid (64 mg, 0.14 mmol). The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in D ₂ O (1.0% TFA) are 1.61 (2H, tt, J=6.9, 7.1 Hz), 2. 72 (2H, t, J = 7.1Hz), 3.04 (2H, t, J = 6.9Hz), 7.62 (1H, s), 7.89 (1H, s), 8.71 ( 1H,s).

5,7-dichloro-4-(3-(3-(methylamino)propyl)ureido)quinoline-2-carboxylic acid (10f) was converted into 4-(3-(3-((tert-butoxycarbonyl)(methyl) ) Amino)propyl)ureido)-5,7-dichloroquinoline-2-carboxylic acid (10e) as described in Synthesis Step VI. The absorption peak values (ppm) found in the ¹ H NMR spectrum performed in D ₂ O (1.0% TFA) are 1.81 (2H, tt, J=6.8, 7.7 Hz), 2. 55 (3H, s), 2.94 (2H, t, J = 7.8Hz), 3.22 (2H, t, J = 6.8Hz), 7.78 (1H, d, J = 1.9Hz ), 8.01 (1H, d, J=1.9Hz), and 8.77 (1H, s). The absorption peak value (ppm) found in the ¹⁹ F NMR spectrum performed in D ₂ O was -73.4. The compound structure is shown in Scheme 4.

Scheme 4.

Synthesis of 3-(2-butyryl-5,7-dichloroquinolin-4-yl)-1,1-diphenylurea

A. 5,7-dichloro-4-(3,3-diphenylureido)-N-methoxy-N-methylquinoline-2-carboxamide (11)
Carbonyldiimidazole (72 mg, 0.44 mmol) and diisoproylethylamine (115 uL, 0.66 mmol) were dissolved in 5,7-dichloro-4-(3,3-diphenylureido)quinoline-2-carboxylic acid ( DCUKA; 100 mg, 0.22 mmol) in dry N,N-dimethylformamide (15 mL). The reaction mixture was stirred at room temperature under nitrogen for 2 hours, then N,O-dimethylhydroxylamine hydrochloride (86 mg, 0.88 mmol) was added. The resulting pale yellow solution was stirred at room temperature for an additional 16 hours, at which point the solvent was removed under reduced pressure and the residue was dissolved in ethyl acetate (20 mL) and saturated sodium bicarbonate solution (2 x 15 mL) and Washed with 0.1 M HCl (2x15 mL) followed by water (15 mL) and brine (10 mL). The organic phase was dried (MgSO ₄ ) and evaporated to dryness. The target compound was obtained as a white solid (81 mg, 0.16 mmol, 73%) after purification by chromatography on silica (1:1 hexane:EtOAc). Rf 0.33 (1:1 hexane:EtOAc); M. p. 207-210°C; 1H NMR (400MHz, CDCl ₃ ) 3.40 (3H, s), 3.75 (3H, br), 7.28 (1H, s), 7.34-7.37 (2H, m), 7.41-7.49 (8H, m), 8.03 (1H, d, J=2.0Hz), 8.87 (1H, s), 9.39 (1H, s).

B. 3-(2-butyryl-5,7-dichloroquinolin-4-yl)-1,1-diphenylurea (12)
A solution of n-propylmagnesium chloride (1.0 M, 1.12 mL, 1.12 mmol) in 2-methyltetrahydrofuran was added to 5,7-dichloro-4-(3,3-diphenylureido)-N-methoxy-N- It was added dropwise to a solution of methylquinoline-2-carboxamide (11, 70 mg, 0.14 mmol) in dry tetrahydrofuran (10 mL) at −10° C. under nitrogen. After the addition, the reaction mixture was stirred at −10° C. for 30 minutes, then warmed to room temperature and stirred for an additional 3 hours. The reaction was quenched with saturated ammonium chloride solution (10 mL) and the product ketone 12 was extracted with ethyl acetate (3x15 mL). The organic extracts were washed with brine (10 mL), dried (MgSO ₄ ) and evaporated to dryness. The residue was purified via chromatography on silica (4:1 hexane:EtOAc) to give the target compound as a pale yellow solid (32 mg, 0.07 mmol, 47%). Rf0.45 (4:1 hexane:EtOAc); M. p. 161-164°C; 1H NMR (400MHz, CDCl ₃ ) 1.03 (3H, t, J = 7.4Hz), 1.80 (2H, qt, J = 7.3, 7.4Hz), 3.24 (2H, t, J=7.3Hz), 7.28 (1H, s), 7.34-7.38 (2H, m), 7.42-7.49 (8H, m), 8.09 (1H, d, J=2.1Hz), 9.15 (1H, s), 9.31 (1H, s).

Synthesis of 5,7-dichloro-4-(3,3-diphenylureido)-N-ethylquinoline-2-carboxamide (13)

Carbonyldiimidazole (143 mg, 0.88 mmol) and diisopropylethylamine (230 uL, 1.32 mmol) were added to 5,7-dichloro-4-(3,3-diphenylureido)quinoline-2-carboxylic acid (DCUKA; 200 mg, 0.44 mmol) in dry N,N-dimethylformamide (25 mL). The reaction mixture was stirred at room temperature under nitrogen for 2 hours, then ethylamine in THF (2.0M, 0.66 mL, 1.32 mmol) was added. The resulting pale yellow solution was stirred at room temperature for an additional 16 hours, at which point the reaction was complete. The solvent was removed under reduced pressure, the residue was dissolved in ethyl acetate (50 mL) and treated with saturated sodium bicarbonate solution (2 x 30 mL) and 0.1 M HCl (2 x 30 mL) followed by water (25 mL) and brine (25 mL). Washed. The organic phase was dried (MgSO ₄ ) and evaporated to dryness. Target ethylamide 13 was purified via silica gel chromatography (1:1 hexane:EtOAc) to give an off-white solid (148 mg, 0.31 mmol, 71%). Rf0.43 (1:1 hexane:EtOAc); M. p. 202-205°C; 1H NMR (400MHz, CDCl ₃ ) 1.31 (3H, t, J = 7.2Hz), 3.56 (2H, q, J = 7.2Hz), 7.28 (1H, s ), 7.32-7.37 (2H, m), 7.41-7.49 (8H, m), 7.99 (1H, s), 8.01 (1H, br), 9.28 ( 1H, s), 9.32 (1H, s).

Synthesis of 5,7-dichloro-4-(3,3-diphenylureido)-N-isopropylquinoline-2-carboxamide (14)

カルボニルジイミダゾール（１４６ｍｇ、０．８８ｍｍｏｌ）及びジイソプロピルエチルアミン（ｄｉｉｓｏｐｒｏｙｌｅｔｈｙｌａｍｉｎｅ）（２３０ｕＬ、１．３２ｍｍｏｌ）を、５，７－ジクロロ－４－（３，３－ジフェニルウレイド）キノリン－２－カルボン酸（ＤＣＵＫＡ；２００ｍｇ、０．４４ｍｍｏｌ）の乾燥Ｎ，Ｎ－ジメチルホルムアミド中溶液（２５ｍＬ）に加えた。反応混合物を、室温で、窒素下で２時間にわたって撹拌し、その後、イソプロピルアミン（１１０μＬ、１．３２ｍｍｏｌ）を加えた。得られた淡黄色溶液を、室温でさらに１６時間撹拌し、この時点で溶媒を減圧下で除去して、残渣を酢酸エチル（５０ｍＬ）中に溶解し、飽和炭酸水素ナトリウム溶液（２ｘ３０ｍＬ）及び０．１Ｍ ＨＣｌ（２ｘ３０ｍＬ）で、その後水（２５ｍＬ）及びブライン（２５ｍＬ）で洗浄した。有機相を、乾燥させ（ＭｇＳＯ_４）、乾燥するまで蒸発させた。標的イソプロピルアミド１４を、シリカゲルクロマトグラフィー（１：１ ヘキサン：ＥｔＯＡｃ）を介して、白色固体を得た（１８２ｍｇ、０．３７ｍｍｏｌ、８４％）。Ｒｆ０．５２（１：１ ヘキサン：ＥｔＯＡｃ）；Ｍ．ｐ．１９７－１９９℃；１Ｈ ＮＭＲ（４００ＭＨｚ、ＤＭＳＯ－ｄ６）１．２３（６Ｈ、ｄ、Ｊ＝６．８Ｈｚ）、４．１５（１Ｈ、ｍ）、７．３４－７．３９（２Ｈ、ｍ）、７．４６－７．５５（８Ｈ、ｍ）、７．７６（１Ｈ、ｄ、Ｊ＝１．９Ｈｚ）、８．１１（１Ｈ、ｄ、Ｊ＝１．９Ｈｚ）、８．５５（１Ｈ、ｄ、Ｊ＝８．２Ｈｚ）、９．００（１Ｈ、ｓ）、９．２１（１Ｈ、ｓ）。

Carbonyldiimidazole (146 mg, 0.88 mmol) and diisopropylethylamine (230 uL, 1.32 mmol) were added to 5,7-dichloro-4-(3,3-diphenylureido)quinoline-2-carboxylic acid (DCUKA; 200 mg, 0.44 mmol) in dry N,N-dimethylformamide (25 mL). The reaction mixture was stirred at room temperature under nitrogen for 2 hours, then isopropylamine (110 μL, 1.32 mmol) was added. The resulting pale yellow solution was stirred at room temperature for an additional 16 hours, at which point the solvent was removed under reduced pressure and the residue was dissolved in ethyl acetate (50 mL), saturated sodium bicarbonate solution (2 x 30 mL) and Washed with .1M HCl (2 x 30 mL), then water (25 mL) and brine (25 mL). The organic phase was dried (MgSO ₄ ) and evaporated to dryness. Target isopropylamide 14 was purified via silica gel chromatography (1:1 hexane:EtOAc) to give a white solid (182 mg, 0.37 mmol, 84%). Rf0.52 (1:1 hexane:EtOAc); M. p. 197-199°C; 1H NMR (400MHz, DMSO-d6) 1.23 (6H, d, J = 6.8Hz), 4.15 (1H, m), 7.34-7.39 (2H, m) , 7.46-7.55 (8H, m), 7.76 (1H, d, J = 1.9Hz), 8.11 (1H, d, J = 1.9Hz), 8.55 (1H, d, J=8.2Hz), 9.00 (1H, s), 9.21 (1H, s).

Example 2. Use of DCUK-OEt as an In Vivo Prodrug for DCUKA This example shows that DCUKA is rapidly formed in vivo by ester hydrolysis after oral administration of DCUK-OEt to rats. This study was conducted in accordance with the NIH Guide for the Care and Use of Laboratory Animals. A spray-dried dispersion of DCUK-OEt was prepared by Catalent Pharma using the polymer HPMCAS-MG (HPMCAS-MG SDD). This SDD contained 15 mg DCUK-OEt and 85 mg polymer per 100 mg SDD. A preparation of 0.5% hydroxypropyl methyl cellulose (HPMC) was prepared by heating 100 ml of water to 60-75°C. Another aliquot of 100 ml water was cooled to 5°C. 500 mg of HPMC was added to 50 ml of hot water with stirring, followed by 50 ml of cold water. Stirring was continued until a clear liquid was formed. To make a suspension of SDD, an aliquot of 15 ml of 0.5% HPMC was added to a vial containing 1 g of SDD. The mixture was ground until a homogeneous slurry containing 10 mg/ml DCUK-OEt was formed. Four rats per group were given 50 mg/kg or 100 mg/kg DCUK-OEt in this suspension by oral gavage. Blood samples were collected from the carotid artery at 0 min pre-dose, 30 min, 60 min, 90 min, 120 min and 180 min post-dose, and in vitro DCUK-OEt hydration of DCUKA with enzymes present in rat blood. Placed in NaF-containing tubes to minimize degradation.

Levels of DCUK-OEt and DCUKA in whole blood samples were determined by evaluating by LC-MS/MS method. Internal standards DCUKA-d10 and DCUKA-OEt-d10 were prepared synthetically (Wempe laboratory, UC Denver School of Pharmacy, Med. Chem. Core Facility). Stock 10.0 mM DMSO solutions of DCUKA, DCUKA-OEt, DCUKA-d10 and DCUKA-OEt-d10 were prepared for standard curves and internal standards, standards and samples were mixed in 4:1 (methanol:acetonitrile, 1 The water (10 mM NH4OAc, 0.1% formic acid) solution used was flowed directly into the mass spectrometer.

Applied Biosys with Shimadzu HPLC (Shimadzu Scientific Instruments, Inc.; Columbia, MD) and Leap autosampler (LEAP Technologies; Carrboro, NC) TEMS Sciex 4000 (Applied Biosystems; Foster City, Calif.) was used. Liquid chromatography used an Agilent Technologies, Zorbax extended-C18 250 x 4.6 mm, 5 column with column guard at 40° C. and a flow rate of 0.6 mL/min. The mobile phase consisted of A: 10 mM (NH4OAc), 0.1% formic acid in H2O, and B: 50:50 ACN:MeOH. The chromatography method used was as follows: 95% A for 2.0 min; ramp to 95% B held for 7.0 min and 9.0 min, and finally back to 95% A. 18.0 min and 2.0 min maintenance (total run time 20.0 min). Compounds were monitored via electrospray ionization ion mode (ESI+) using the following conditions: i) ion spray voltage of 5500 V; ii) temperature, 450 ^o C; iii) curtain gas (CUR; set to 10). and collisional activated decomposition (CAD; set to 12) gas is nitrogen; iv) ion depletion gas 1 (GS1) and 2 (GS2); v) inlet potential set to 10 V; vi) quadruple 1 (Q1) and quadruple 3 (Q3) are set to unit derivation; vii) residence time is set to 200 msec; and viii) declustering potential (DP), collision energy (CE), and collision cell exit potential (CXP) are: It is voltage (V). Samples (10 μL) were analyzed by LC/MS-MS using the following fragmentation for quantification: DCUKA, 452→168 m/z, t _R =5.3 min; DCUKA-OEt: 480→168 m /z, t _R =5.6 min; internal standard DCUKA-d10:462→178 m/z; and internal standard DCUKA-OEt-d10:490→178 m/z.

Figure 1 illustrates that DCUK-OEt can serve as a prodrug for DCUKA after in vivo administration. Data are plotted as mean±SD values from 3-4 rats per group (data not included from one outlier 60 minutes after the 100 mg/kg dose). 50 mg/kg or 100 mg/kg of DCUK-OEt, a spray-dried dispersion prepared using the polymer HPMCAS-MG, was administered by gavage as an HPMC suspension to four rats per group. Blood was obtained from the carotid artery at the indicated times and DCUKA levels were determined by LC-MS/MS analysis. The results show the blood levels of DCUKA obtained after administration of DCUK-OEt. DCUK-OEt was detectable only after the 100 mg/kg dose. The highest levels of DCUK-OEt were 0.49 μM and 0.24 μM 60 minutes after DCUK-OEt administration and 0.08 μM 90 minutes after DCUK-OEt administration. Levels of DCUK-OEt were below detection in the fourth rat in the group. In contrast, as shown in Figure 1, DCUKA levels reached approximately 3 μM after 50 mg/kg of DCUK-OEt and 100 mg/kg of CUK-OEt.

Example 3. Treatment of Neuropathic Pain with DCUKA, BCUKA and DCUK-OEt This example demonstrates the ability of DCUKA, BCUKA and DCUK-OEt to reverse neuropathic pain (cisplatin (cancer chemotherapy), complete Freund's adjuvant). (CFA) (inflammatory pain), or organic or febrile pain induced by diabetes (streptozotocin-induced pain) or monoiodoacetate (MIA) (osteoarthritic pain)).

All studies were conducted in accordance with the NIH Guide for the Care and Use of Laboratory Animals.

drugs. For in vivo studies of cisplatin, CFA and STZ-induced pain, DCUKA or BCUKA or DCUK-OEt, or gabapentin was prepared in a 50% gelatin/50% canola oil emulsion (this emulsion was used as the vehicle). Gelatin was prepared by adding 0.8 g of gelatin Knox (Kraft Foods North America, Tarrytown NY) and 0.06 g of tartaric acid (McCormick and Co., Inc., Hunt Valley, MD) to 30 ml of purified water. The solution was heated to 98°C for 20 minutes and then cooled to 50°C. 6 ml of 95% alcohol and water were added to make 50 ml of gelatin. Various amounts of DCUKA or BCUKA or DCUK-OEt, or gabapentin were added to 5 ml of canola oil (Safeway Inc., Pleasanton, Calif.), stirred, and sonicated for 5 minutes (VWR BIOSONIK IV, 70%). The drug suspension was then added to 5 ml of gelatin, stirred and sonicated. Emulsions were diluted with vehicle as desired and warmed to 37°C for oral administration to animals. Immediately prior to oral gavage, the emulsion was agitated using a vortex mixer.

For in vivo studies of MIA-induced pain, DCUKA was combined with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS 1000). DCUK-OEt (2.5 g) was weighed into a clean glass beaker and TPGS 1000 (47.5.ml) was added slowly. The mixture was mixed for 2-3 minutes to form a creamy white aqueous suspension. This suspension was enclosed in Torpac capsules (Torpac, Fairfield, NJ) and delivered to rats orally using a Torpac capsule syringe (Wempe et al., 2012).

Four different drugs were used to induce neuropathic pain. Cisplatin (Sigma-Aldrich, St. Louis, MO) was dissolved in a 0.9% saline solution. Streptozotocin (Sigma-Aldrich) was dissolved in 20mM sodium citrate buffer, pH=4.5. Complete Freund's adjuvant (CFA) was obtained from Sigma-Aldrich. Sodium monoiodoacetate was obtained from Sigma-Aldrich and dissolved in saline.

Measurement of organic hyperalgesia. These studies were conducted in male Sprague-Dawley rats (Taconic, Germantown PA or Harlan, Indianapolis IN), approximately 8 weeks old. Rats were housed in an AAALAC-qualified facility with controlled lighting, temperature, and humidity. Pain was tested using an electronic von Frey anesthesiometer (IITC Life Science, Woodland Hills, CA). Rats were placed in a hanging chamber with a metal mesh floor and allowed to habituate for approximately 20 minutes. Organic stimulation was applied to the midplantar surface of the hind paw. Two different methods were used. In the first, a series of von Frey filaments of different strength ranges (g) were used, increasing the strength of the filaments applied to the paw, and the application of force to each filament was indicated by an electrical sensor. Each filament was applied five times until the paw developed a withdrawal response (a "wince" after filament application). The test was stopped if the filament caused paw withdrawal in 4 out of 5 trials or if maximum stimulation (10% of body weight) was reached. Paw withdrawal threshold was calculated in g using the average of the four values. In the second method, a semi-flexible filament was placed against the midplantar surface of the paw and pressure was increased until paw withdrawal was observed. Pressure (g-force) at paw withdrawal (paw withdrawal threshold) was recorded by an electrical transducer. Five measurements were taken per test and the average value was calculated. In both methods, a 3 minute interval was allowed between measurements to avoid sensitization.

Acute effects of DCUKA, BCUKA, DCUK-OEt and gabapentin in reversing neuropathic pain (organic hyperalgesia) caused by cisplatin, complete Freund's adjuvant (CFA), streptozotocin (STZ) or monoiodoacetate (MIA). Acute effects of DCUKA on cisplatin-induced pain: Two methods of cisplatin administration were used. 1) Cisplatin was dissolved in 0.9% saline (1 mg/ml) and injected into the tail vein in a volume of 1.5 or 2.5 ml/kg of body weight. The intravenous injection of cisplatin was followed by an equal volume of saline injection (Joseph and Levine, 2009). Cisplatin dose was 1.5 or 2.5 mg/kg in each experiment. 2) Cisplatin was dissolved in 0.9% saline and injected intraperitoneally on days 1, 4, 8 and 12. Cisplatin doses were 2 mg/kg, 1 mg/kg, 2 mg/kg and 2 mg/kg, respectively, with a total dose of 7 mg/kg. A fresh solution of cisplatin was prepared daily before injection and 0.9% saline (2 ml) was injected subcutaneously after cisplatin injection (to avoid nephrotoxicity). In all experiments, rats were tested for baseline pain sensitivity (organic pain threshold) before any cisplatin treatment. The experimental design using intravenous injection was as follows: (1) Starting 1 hour after cisplatin injection, rats were given vehicle (canola oil/gelatin) orally (by intragastric gavage) for 3 hrs. (These rats are controls for a study on the prevention of cisplatin-induced pain; see below). On day 4, rats were again tested for organic pain threshold. On day 5, rats received 50 mg/kg DCUKA or vehicle and organic pain thresholds were tested 1 hour later. 2) Four days after cisplatin treatment, rats were given various doses of DCUKA (12.5, 25, 50, or 75 mg/kg) or vehicle by intragastric gavage to reduce the organic pain threshold to 1 Tested after hours. 3) Six days after cisplatin treatment, organic pain thresholds were measured and rats were given 50 mg/kg DCUKA or vehicle orally. Organic pain thresholds were tested 1 hour later. 4) Six days after cisplatin treatment, rats were given various doses of DCUKA (25, 50 or 75 mg/kg) or vehicle and 1 hour later, organic pain thresholds were measured. The experimental design for the experiment in which cisplatin was administered intraperitoneally was as follows: After 14 days (days 1, 4, 8, 12) of cisplatin treatment, organic pain thresholds were tested. Rats were then given 50 mg/kg DCUKA or vehicle orally and organic pain thresholds were measured 1 hour later. Data were reported as the ratio of organic pain threshold measured after DCUKA treatment to baseline pre-cisplatin organic pain threshold (measured on the same paw).

Data analysis for cisplatin experiments: Acute effects and meta-analysis of DCUKA:
Depending on the experimental design, it consists of either a one-way analysis of variance of repeated measurements or a two-way analysis of variance of repeated measurements (Proc Mixed, SAS v9.3, Cary, NC). Treatment and time were the main fixed independent effects tested. In one experimental treatment, time and interactions between the two were evaluated. Since multiple measurements are taken on one animal, including pre- and post-treatment and right and left paws, the animal identification number was used as the repeated measurement. All models were tested for equality of variance (Barlett's test for equality of variances) and normality (Kolmogorov-Smirnov goodness-of-fit test) between treatment groups. If the data did not meet these assumptions, we therefore adjusted in a mixed model. Some analyzes used Fisher's LSD post hoc test to compare statistical significance between different treatment doses (p-value < 0.05), and all analyzes compared treatment group and baseline values. Fisher's LSD post hoc test was used to compare statistical significance between

Experiments were included in the meta-analysis if they met the following requirements:1. 2. Organic pain was measured using the von Frey test. Cisplatin treatment successfully induced pain (25% reduction in organic pain threshold) and 3. Organic pain was measured within 90 minutes after DCUKA administration. A mixed model with DCUKA dose as a fixed independent variable with five different class levels, study identification as both random and repeated measures, and rat identification as a random effect was developed for overall neuropathic pain. (Proc Mixed, SAS v9.3, Cory, NC). Fisher's LSD post hoc test was used for pairwise comparisons of DCUKA doses.

Comparison of the effects of DCUKA, BCUKA and gabapentin on cisplatin-induced pain. Cisplatin was administered intraperitoneally on days 1 (2 mg/kg), 4 (1 mg/kg), 8 (2 mg/kg), and 12 (2 mg/kg) (total dose 7 mg/kg). administered. Cisplatin was prepared daily and 2 ml of 0.9% saline was administered subcutaneously after each cisplatin injection. On day 14, organic pain thresholds were measured and vehicle (canola oil/gelatin), DCUKA (50 mg/kg), BCUKA (50 mg/kg) or gabapentin (30 mg/kg, equimolar doses for DCUKA and BCUKA) ) was given to rats. After 1 and 2 hours, organic pain thresholds were tested again. Data are reported as the ratio of organic pain thresholds measured after DCUKA, BCUKA or gabapentin treatment to baseline organic pain thresholds (measured on the same paw). Statistical analysis was a two-way analysis of variance for repeated measurements (Proc Mixed, SAS v9.3). Treatment and time were the main fixed independent effects; interactions were also tested. Animal identification numbers were used for repeated measurements. Fisher's LSD post hoc test was used to compare significance (p<0.05) between different times within treatment groups.

Acute effects of DCUKA on complete Freund's adjuvant (CFA)-induced neuropathic pain. After measuring the baseline paw withdrawal threshold, CFA (0.1 ml) was administered subcutaneously under light to the midplantar surface of the left hind paw with isoflurane anesthesia (5% for induction and 2% for maintenance). %). Rats were caged for 48 hours. Paper bedding was used to avoid pressure neuropathy caused by hard bedding. At 48 or 60 hours after CFA injection, rats were given vehicle (canola oil/gelatin) orally by intragastric gavage or various doses of DCUKA to determine their organic pain thresholds. The decision was made after 1 hour. Data are expressed as the ratio of organic pain threshold measured after DCUKA treatment to baseline organic pain threshold.

Data analysis of CFA experiments. Meta-analysis of acute effects of 50 mg/kg DCUKA and DCUKA dose response. Each experiment was analyzed by one-way analysis of variance (Proc Glm or Proc Mixed, SAS v9.3, Cary, NC). Treatment group was a fixed independent effect tested. All models were tested for equality of variance (Barlett's test for equality of variances) and normality (Kolmogorov-Smirnov goodness-of-fit test) between treatment groups. If the data did not meet these assumptions, a mixed model was used. All analyzes used Fisher's LSD post hoc test to compare statistical significance between different treatment groups (p-value <0.05).

Comparison of the effects of DCUKA and BCUKA on CFA-induced neuropathic pain. Baseline organic pain thresholds were determined and animals were treated with CFA as described above. At 48 hours after aCFA treatment, rats received vehicle (canola oil/gelatin) (n=17), 50 mg/kg DCUKA (n=17) or 50 mg/kg BCUKA (n=6). Organic pain thresholds are tested 1 hour later and data are reported as the ratio of pain thresholds after vehicle, DCUKA or BCUKA treatment to baseline pain thresholds measured on the same paw. Statistical significance was determined using one-way analysis of variance followed by Fisher's LSD post hoc test (p<0.05).

Acute effects of DCUKA on streptozotocin (STZ)-induced neuropathic pain (a model of diabetic neuropathic pain). After baseline limb withdrawal threshold measurements, baseline body weight and blood glucose concentration were determined (blood glucose was measured in tail blood using an ASCENSIA CONTOUR Blood Glucose Monitoring System, Bayer, Pittsburgh, PA). Rats were fasted overnight and injected intraperitoneally with vehicle (20 mM sodium citrate, pH 4.5, Sigma-Aldrich) or 50 mg/kg STZ in vehicle. STZ solutions were prepared daily and used within 10 minutes. Rats were given chow 30 minutes after STZ treatment. Three days after STZ treatment, blood glucose levels were measured again and rats with blood glucose levels above 350 mg/dl were considered "diabetic". Using the same procedure, rats were given a second dose of STZ (45 mg/kg) when blood glucose levels were below 350 mg/dl. Fourteen days after the first STZ treatment, rats were given vehicle (canola oil/gelatin) or various doses of DCUKA orally and organic pain thresholds were tested at various time points after these treatments. Data are expressed as the ratio of organic pain threshold after DCUKA treatment to baseline organic pain threshold (measured on the same paw).

Individual experiment analysis. If the organic pain threshold to baseline ratio was outside the corresponding treatment group mean ± 2 standard deviations, the data point was considered an outlier and excluded from the data set. Nuclear experiments were analyzed with one-way analysis of variance (Proc Glm or Proc Mixed, SAS v9.3, Cary, NC). Treatment group was a fixed independent effect tested. All models were tested for equality of variance (Barlett's test for equality of variances) and normality (Kolmogorov-Smirnov goodness-of-fit test) between treatment groups. If the data did not meet these assumptions, a mixed model was used. All analyzes used Fisher's LSD post hoc test to compare statistical significance between different treatment groups (p-value <0.05).

Acute effects of DCUKA on monoiodoacetate (MIA)-induced neuropathic pain (a model of osteoarthritis neuropathic pain). Rats were anesthetized with isoflurane, the right knee was shaved, and disease was induced by injection with vehicle or MIA. Animals were weighed weekly until pain measurements were taken on day 20. Baseline paw withdrawal measurements were performed in animals not treated with MIA. On day 21, groups of animals were dosed orally with vehicle or DCUKA (1 or 2 capsules, po; dose approximately 50 mg/kg or 100 mg/kg). Organic pain thresholds were tested 90 minutes after drug administration. At the end of the study, blood was collected from the tail vein for determination of DCUKA levels by LC-MS/MS analysis. Data are expressed as the ratio of organic pain thresholds after DCUKA treatment to organic pain thresholds determined in animals without drug or MIA treatment.

Data analysis of MIA experiments. Experiments were analyzed by one-way analysis of variance (Sigma Plot 12) and using the Holm-Sidak post hoc test for all pairwise comparisons. P values <0.05 were considered statistically significant. Since administration of one capsule of DCUKA had no statistically significant effect on organic pain thresholds (Figure 8), blood levels of Kindolor were evaluated after this treatment. We determined that a blood level of Kindolor <500 ng/ml (<1.1 mM) was obtained after administration of one capsule, making this blood level ineffective in the treatment of MIA-induced neuropathic pain. It was considered.

Figure 2 shows that DCUKA (50 mg/kg) treatment reverses the neuropathic pain caused by treatment of rats with the cancer chemotherapy treatment cisplatin. The combined results of six experiments are shown. Treatment means ± 1 SEM were plotted. ^* P value <0.0001 compared to control (0 mg/kg DCUKA). In all experiments, rats were tested for baseline organic pain threshold before cisplatin treatment. After cisplatin treatment as described above, rats were given DCUKA and 1 hour later organic pain thresholds were determined again. Results represent the ratio of organic pain threshold measured 1 hour after vehicle or DCUKA administration to baseline (pre-cisplatin treatment) organic pain threshold.

Figure 3 shows the chemotherapeutic agent cisplatin. Figure 2 graphically compares the effects of DCUKA (50 mg/kg), BCUKA (50 mg/kg) and gabapentin (neuron tin, 30 mg/kg) on neuropathic pain induced by. Mean organic pain thresholds ± 1 standard error were plotted for each treatment group and time. ^* P<0.05 compared with the corresponding pre-treatment group. Rats were tested for baseline organic pain thresholds prior to cisplatin treatment and treated with cisplatin as described above. After cisplatin treatment, organic pain thresholds were measured and rats received an oral dose of vehicle, DCUKA, BCUKA, or gabapentin. Organic pain thresholds were measured again 1 and 2 hours after these treatments. Data are the ratio of organic pain thresholds measured before and 1 and 2 hours after administration of DCUKA, BCUKA or gabapentin. Cisplatin treatment alone (“pre-treatment”) significantly lowers organic pain thresholds compared to baseline, and DCUKA and BCUKA significantly reverse the decrease in organic pain thresholds. Gabapentin did not significantly reverse the cisplatin-induced reduction in organic pain threshold at equimolar doses of DCUKA and BCUKA.

FIG. 4 illustrates that DCUKA treats neuropathic pain (resulting in an inflammatory response) induced by treatment with complete Freund's adjuvant (CFA) in rats. Data are combined from three experiments. In each experiment, baseline organic pain thresholds (force to cause paw dislocation, g) were first measured using an electrical von Frey anesthesia monitoring device. Rats were then injected with 0.1 ml of complete Freund's adjuvant (CFA) into the midplantar surface of the left hind paw. After 48-60 hours, upon onset of CFA-induced pain, vehicle (gelatin/canola oil emulsion) or 50 mg/kg DCUKA was given orally. One hour later, organic pain thresholds were measured again. Results show the ratio of organic pain thresholds measured after vehicle or DCUKA treatment to baseline organic pain thresholds. Post hoc Fisher's LSDt test for pairwise comparisons showed a significant ( ^* ) difference between 50 mg/kg DCUKA and 0 mg/kg DCUKA (p-value < 0.0001). CFA treatment reduced organic pain thresholds by approximately 60%, DCUKA treatment reversed this effect and reduced organic pain thresholds in CFA-treated feet to levels that were not significantly different from baseline levels. increased.

FIG. 5 illustrates a comparison of the effectiveness of DCUKA (50 mg/kg) and BCUKA (50 mg/kg) in treating neuropathic pain induced by CFA treatment. The organic pain threshold for each animal is expressed as a ratio to the paw-only injection baseline. The mean organic pain threshold ±1 standard error is plotted for each treatment group. ^* P<0.05 compared to vehicle. Baseline organic pain thresholds were measured and rats were treated with CFA as described above. After 48 hours, rats were given vehicle (canola oil/gelatin), DCUKA or BCUKA, and organic pain thresholds were measured 1 hour later. CFA treatment lowered the organic pain threshold by approximately 40% from baseline, and treatment with DCUKA (n=17) or BCUKA (n=6) lowered the organic pain threshold to a level that was not significantly different from baseline. Invert until .

The dose-dependent effect of DCUKA on neuropathic pain caused by CFA was determined using a meta-analytic approach. The results are shown in FIG. The organic pain threshold for each animal is expressed as a ratio to the paw-only injection baseline. The mean organic pain threshold ±1 standard error was plotted for each treatment group. This is based on the treatment average from the 5 studies included in the meta-analysis. ^* P<0.05 compared to vehicle (0 mg/kg) treated group. In all experiments using CFA, baseline organic pain thresholds were measured by an electrical von Frey anesthesia monitoring device. CFA was injected into the midplantar surface of the left hind paw and 48 hours after injection rats were given oral vehicle (gelatin/canola oil) or DCUKA. Organic pain thresholds were given again 60 minutes after vehicle or DCUKA administration. For experiments to be included in the meta-analysis, the requirements are: 1) CFA treatment caused at least a 25% reduction in organic pain threshold; 2) pain threshold decreased 60 minutes after DCUKA or vehicle administration. It was measured. Five experiments testing different doses of DCUKA met these requirements. Organic pain thresholds are expressed as mean ± SEM as a ratio to baseline organic pain threshold. These are significant overall effects of DCUKA (F(5,125)=7.71, P<0.0001). CFA treatment reduced organic pain threshold by approximately 60%, and this effect was significantly reversed by DCUKA at doses of 30 mg/kg and above. That is, pain threshold returned to baseline level.

Figure 7 shows that DCUKA reverses neuropathic pain associated with diabetes. Diabetes is induced in rats by injection of streptozotocin (STZ) as described above. Post hoc Fisher's LSDt test for pairwise comparisons showed a significant ( ^* ) difference between 50 mg/kg DCUKA and 0 mg/kg DCUKA (difference = 0.60, p-value < 0.0001). Combined data from three experiments is shown. In each experiment, baseline organic pain thresholds were tested using an electrical von Frey anesthesia monitoring device. Fourteen days after STZ treatment, vehicle (gelatin/canola oil) or 40 or 50 mg/kg DCUKA (these doses had no significant difference in efficacy) were administered orally and 90 minutes later, the organic Pain was assessed. Results show the ratio of organic pain threshold after vehicle/DCUKA treatment to baseline organic pain threshold. STZ lowered organic pain threshold by approximately 40%, and this effect was reversed to baseline levels by DCUKA treatment.

The dose dependence of the effect of DCUKA on STZ-induced neuropathic pain was determined by a meta-analysis approach. The requirements for experiments to be included in the meta-analysis are as follows: 1) STZ treatment induced neuropathic pain, measured as a reduction in organic pain threshold of at least 25%; 2) pain Measurements were taken 90 minutes after vehicle or DCUKA treatment. Four experiments meeting these criteria were included in the meta-analysis.

Figure 8 shows the dose dependence of the effect of DCUKA in treating STZ-induced neuropathic pain. Data are reported as the ratio of organic pain thresholds after vehicle or DCUKA treatment to baseline pain thresholds (measured on the same paw). ^* P<0.05 compared to vehicle treated group. The effect of DCUKA on organic pain threshold was overall significant (F(7,115=8.48, p<0.0001).STZ treatment resulted in an approximately 40% reduction in pain threshold. DCUKA at doses of 30 mg/kg or higher reversed the effects of STZ, raising pain thresholds back to baseline levels.

Figure 9 shows the dose dependence of DCUKA in treating MIA-induced neuropathic pain. Data were reported as the mean ± SEM ratio of organic pain thresholds after vehicle (0 capsules) or DCUKA treatment (1 or 2 capsules) versus baseline pain thresholds measured in animals not treated with MIA or drug. ^* P<0.05 (analysis of variance and post hoc comparison) compared to vehicle group. The effect of DCUKA on organic pain threshold was overall significant (F(2,26)=4.07, p=0.029). MIA treatment resulted in an approximately 60% reduction in pain threshold, and a DCUKA dose of approximately 100 mg/kg (2 capsules) significantly reversed the effects of MIA.

Example 4 DCUKA and DCUK-OEt enhance the effects of morphine on CFA-induced neuropathic pain.
The following data demonstrate that low doses of DCUKA together with morphine have a synergistic effect on reducing organic allodynia and thermal hyperalgesia pain induced by inflammatory agents.

CFA treatment and measurement of organic pain thresholds are described in Example 3. In this experiment, organic pain thresholds were tested at baseline. Forty-eight hours after CFA treatment, vehicle, DCUKA or morphine, or a combination of DCUKA and morphine was injected 30 minutes before measurement of organic pain thresholds.

Heat hypersensitivity test (radiant heat foot withdrawal test). Rats were placed on a glass surface in a clear plastic chamber and habituated 15 minutes before testing. Heat sensitivity was measured by using paw withdrawal latency to radiant heat stimulation. A radiant heat source (ie, infrared) was activated with a timer and focused on the midplantar surface of the left hind paw. A motion detector that stopped both the lamp and timer when the paw was withdrawn determined paw withdrawal latency. This latency was measured before and after administration of drug or vehicle. A maximum cutoff of 33 seconds was used to prevent tissue damage. In this experiment, rats were injected with DCUK-OEt, immediately followed by increasing dose ratios of morphine, and tested 30 minutes later.

FIG. 10A demonstrates that the combination of doses of DCUKA and morphine, each of which is ineffective in producing analgesia, results in complete reversal of inflammation-induced chronic pain. These data demonstrate that the combination of DCUKA and morphine has a greater effect than the additive effect of each drug alone, as determined by each of the "effect-based strategy" approaches discussed by Foucquier & Guedj (2015). This is consistent with the conclusion. This figure illustrates a "subthreshold combination" approach, where combinations of ineffective doses of drugs result in a sufficient effect. Figures 10B and 10C provide evidence that the combination of DCUK-OEt and morphine provides a more than additive effect compared to the effects of either agent alone. In this case, thermal hyperalgesia developed by CFA treatment was tested. The ED ₅₀ of the antihyperalgesic response to morphine was significantly reduced by administering DCUK-OEt at a dose ratio to morphine of >30:1. For example, morphine at a dose of 0.2 mg/kg produces an anti-hyperalgesic response of approximately 20%. When combined with 6.4 mg DCUK-OEt, the response increases to 40%. DCUK-OEt was found to have a DCUK-OEt/morphine dose ratio of 18:1 (HP<0. 7) and 32:1 ( ^* P<0.05).

Example 5 DCUKA increases the effectiveness of oxycodone and methadone in treating FA-induced neuropathic pain.
The following data demonstrate that low doses of DCUKA potentiate the effect of low doses of oxycodone or methadone in reducing organic allodynia developed by inflammatory agents. Data are presented as the mean ± SEM ratio of organic pain threshold after drug or vehicle (VEH) treatment to organic pain threshold before treatment with Freund's adjuvant (FA) in treated paws. P<0.05 compared to vehicle treated group (n=8/group, ANOVA and post hoc comparisons).

After the baseline organic pain test, rats were injected into the right hind paw with a mixture of incomplete Freund's adjuvant (FA) and Mycobacterium butyricum (similar to complete Freund's adjuvant). After 72 hours, the organic pain test was repeated using the full version of the Von Frey test procedure described in Example 3. Rats were tested with a series of von Frey hairs ranging from 3.16 to 5.18 absolute thresholds. Each hair was applied three times to determine which hair stiffness the rats responded to 100% of the time. Data were analyzed by the Psychofit program. On day 4, groups of rats were given vehicle or a dose of DCUKA (1 or 2 capsules, p.o., as described in Example 3) or a dose of oxycodone (as described in Example 3) to determine the response to individual drugs. 0.1, 0.25 or 1 mg/kg ip) or a dose of methadone (1.5, 2.5 or 3.5 mg/kg ip) and the von Frey test was performed 75-90 minutes after dosing. did. On day 8, the effect of a combination of low dose (1 capsule) DCUKA and low dose oxycodone or methadone was evaluated. Rats received DCUKA+vehicle, oxycodone+vehicle, methadone+vehicle, or DCUKA+oxycodone or DCUKA+methadone using doses determined from the early stages of the study. FIG. 11 demonstrates that the combination of doses of DCUKA (1 capsule) and oxycodone (0.1 mg/kg), each of which is not effective to produce anti-hyperalgesia, results in relief of inflammation-induced chronic pain. These data demonstrate that the combination of DCUKA and oxycodone has a greater than additive effect of each drug alone, as determined by all four of the “effect-based strategy” approaches discussed by Foucquier and Guedj (2015). This is consistent with the conclusion that it is effective. This figure illustrates a "subthreshold combination" approach, where combinations of ineffective doses of drugs result in a sufficient effect. Solid lines are for animals treated with Freund's adjuvant and vehicle. Baseline organic pain threshold ratios are shown. An increase above this line indicates a (non-significant) effect of DCUKA or oxycodone alone. Dashed lines indicate the expected additive effects of drug combinations. An increased effect of the drug combination (i.e., DCUKA + oxycodone 0.1 mg/kg) above the dashed line indicates a “positive combination effect” (Foucquier and Guedj, 2015).

Figure 12 demonstrates that DCUKA (1 capsule) potentiates the effect of methadone (1.5 or 3.5 mg/kg) on reducing inflammation-induced chronic pain. Data are expressed as the mean ± SEM ratio of organic pain threshold in the treated paw after drug or vehicle (VEH) treatment to organic pain threshold before treatment with Freund's adjuvant (FA). ^* P < 0.05 compared to DCUKA/VEH or methadone 1.5 mg/kg alone; ^** P < 0.05 compared to DCUKA/VEH or methadone 3.5 mg/kg alone +P<0.05 compared to VEH (n=8/group, analysis of variance and post hoc comparison).

These data demonstrate that the combination of DCUKA and methadone has a greater effect than the additive effects of each drug alone, as determined by each of the “effects-based strategy” approaches discussed by Foucquier and Guedj (2015). This is consistent with the conclusion that For 1.5 mg/kg of methadone, this figure illustrates a "subthreshold combination" approach in which combinations of ineffective doses of the drugs result in full effect. The solid black line indicates the baseline organic pain threshold ratio in animals treated with front adjuvant and vehicle. Increases above this line represent a (non-significant) effect of DCUKA or methadone (1.5 mg/kg) alone. The gray line shows the predicted additive effect of the combination of DCUKA and 1.5 mg/kg methadone. The increased efficacy of the combination of DCUKA and methadone 1.5 mg/kg indicates a “positive combination effect” (Foucquier and Guedj, 2015). For 3.5 mg/kg methadone, the figure illustrates a "best single agent" approach where the effect of the drug combination is greater than the effect produced by the individual components. The dashed line indicates the expected additive effect of 3.5 mg/kg methadone and DCUKA. The increased efficacy of drug combinations above this line reflects a “positive combination effect” (Foucquier and Guedj, 2015).

Example 6 DCUKA increases the effectiveness of tramadol in treating MIA-induced neuropathic pain.
The following data demonstrate that low doses of DCUKA, along with low doses of another narcotic analgesic (tramadol), synergistically reduce hyperalgesia in another model of chronic pain, the MIA osteoarthritis model. do. Tramadol acts at m-opiate receptors and is also a serotonin and norepinephrine reuptake inhibitor.

As described in Example 3, the acute effects of different doses of DCUKA in rats after administration of MIA were first tested 21 days after MIA treatment. The results are shown in FIG. Administration of one capsule of DCUKA (approximately 50 mg/kg) had no significant effect on MIA-induced pain. Blood levels of DCUKA 2-2.5 hours after dosing were then determined to be <500 ng/ml (<1.1 μM). This blood level of DCUKA was not thought to be effective in alleviating MIA-induced neuropathic pain. Rats were again tested for organic pain thresholds 29 days after treatment with MIA (pain thresholds were re-evaluated on day 28 and determined to be no significant difference between initial testing and day 20. did). Rats were administered vehicle, 1 capsule (low dose) of DCUKA, p.p. as described in Example 3. o. , 5 mg/kg (low dose) p. o. Tramadol or 1 capsule of DCUKA + 5 mg/kg tramadol was given 90 minutes before the measurement of organic pain thresholds and after testing for evaluation of DCUKA levels by the LC-MS/MS method described in Example 2. Blood was collected from the carotid artery.

Data analysis. Data are expressed as the ratio of baseline organic pain threshold for no-MIA, no-drug treatment to organic pain threshold after drug treatment. Two outlier data in the DCUKA+tramadol group are removed from the analysis. Animals with blood levels of DCUKA <500 ng/ml (a level previously found not to be effective in reversing MIA-induced neuropathic pain) are considered to be receiving a "low dose" of DCUKA. . Data from these animals were used for analysis of differences between groups by one-way analysis of variance and Holm-Sidak test for all pairwise comparisons.

Figure 13 shows that the dose of DCUKA (1 capsule, where the blood level of DCUKA is <500 ng/ml) and We demonstrate that tramadol (5 mg/kg) when combined results in a significant reversal of the pain threshold reduction caused by MIA treatment. Data are expressed as mean organic pain thresholds after treatment with low dose DCUKA, low dose (5 mg/kg) tramadol, or a combination of low dose DCUKA and low dose tramadol versus organic pain threshold before MIA treatment. Expressed as ±SEM. ^* P<0.05 (analysis of variance and post hoc comparisons) compared to all other groups.

These data demonstrate that the combination of DCUKA and tramadol has a greater effect than the additive effect of each drug alone, as determined by each of the “effect-based strategy” approaches discussed by Foucquier and Guedj (2015). This is consistent with the conclusion that The figure illustrates a "best single agent" approach where the effect of the drug combination is greater than the effect produced by the individual components. Solid lines indicate baseline organic pain threshold ratios in MIA and vehicle treated animals. A (non-significant) effect of tramadol is indicated by an increase over baseline, which is indicated by the dashed line. The effect of a drug combination above the dashed line reflects a “positive combination effect” (Foucquier and Guedj, 2015).

Example 7 DCUKA increases the effectiveness of aspirin in treating STZ-induced neuropathic pain.
The data below demonstrate that in another model of chronic pain, the STZ diabetic neuropathy model, DCUKA can synergize with another analgesic (aspirin) to reduce allodynia.

After administration of streptozotocin (STZ), rats were placed in a von Frey apparatus as described in Example 3. was used to test for allodynia. Sixty minutes before testing, rats were divided into four groups. Group 1 received vehicle; Group 2 received DCUKA; Group 3 received aspirin; and Group 4 received a combination of DCUKA and aspirin.

FIG. 14 shows that combining doses of DCUKA (12.5 mg/kg) or aspirin (25 mg/kg), which individually have no significant effect on allodynia, completely reverses the hyperresponsiveness, i.e. Demonstrate return of pain threshold to baseline level. These data demonstrate that the combination of DCUKA and aspirin has a greater effect than the additive effect of each drug alone, as determined by each of the “effect-based strategy” approaches discussed by Foucquier and Guedj (2015). This is consistent with the conclusion that This figure illustrates a "subthreshold combination" approach, where combinations of ineffective doses of drugs result in a sufficient effect.

Example 8 DCUKA enhances the efficacy of treating FA-induced neuropathic pain.
The following data demonstrate that a low dose of DCUKA (1 capsule, as described in Example 1) potentiates the effect of low doses of diclofenac in reducing organic allodynia produced by inflammatory agents. Demonstrate. Data are expressed as the mean ± SEM ratio of organic pain threshold in the treated paw after drug or vehicle (VEH) treatment versus organic pain threshold before treatment with Freund's adjuvant (FA). ^* P<0.05 compared to DCUKA or diclofenac 1.5 mg/kg alone; ^** P<0.05 compared to DCUKA or diclofenac 10 mg/kg alone (analysis of variance and post hoc comparisons).

Rats were treated with Freund's adjuvant and tested for organic pain as described in Examples 2 and 5. Groups of rats were given different doses of diclofenac on day 4 to determine the appropriate dose for experiments testing the combined effect of DCUKA and diclofenac. Different groups of rats were tested on day 4 for administration of 1 capsule of DCUKA or low dose of diclofenac alone and in combination. Figure 15 shows that DCUKA potentiates the effect of diclofenac in reducing inflammation-induced chronic pain. These data demonstrate that the combination of DCUKA and diclofenac has a greater effect than the additive effect of each drug alone, as determined by each of the “effect-based strategy” approaches discussed by Foucquier and Guedj (2015). This is consistent with the conclusion that For diclofenac at 1.5 mg/kg, this figure illustrates a "subthreshold combination" approach in which combinations of non-effective doses of drugs result in full effect. The solid black line indicates the baseline organic pain threshold ratio in animals treated with front adjuvant and vehicle. An increase above this line represents a (non-significant) effect of DCUKA or diclofenac (1.5 mg/kg) alone. The gray line shows the predicted additive effect of the combination of DCUKA and 1.5 mg/kg diclofenac. The increased effect of the combination of DCUKA and diclofenac 1.5 mg/kg above the gray line indicates a "positive combination effect". For 10 mg/kg diclofenac, the figure illustrates a "best single agent" approach where the effect of the drug combination is greater than the effect produced by the individual components. The dashed line indicates the expected additive effect of DCUKA and diclofenac 10 mg/kg. An increased effect of a drug combination above this dashed line indicates a “positive combination effect” (Foucquier and Guedj, 2015).

Example 9 Prevention of cisplatin- and CFA-induced neuropathic pain with DCUKA.
The following data show that treatment of animals with DCUKA after injury but before the onset of neuropathic pain can prevent the onset of pain. Rats were treated with cisplatin or CFA and organic pain thresholds were measured as described in Example 3.

Prevention of CFA-induced neuropathic pain by DCUKA. After baseline measurements of organic pain thresholds, rats were treated with CFA as described above. After CFA injection, rats were given vehicle (canola oil/gelatin) (n=7) or 50 mg/kg DCUKA (n=7) orally by intragastric gavage. Rats then received three or more treatments with vehicle or DCUKA at 12 hour intervals. Sixty hours after CFA treatment, organic pain thresholds were tested again.

Prevention of cisplatin-induced neuropathic pain with DCUKA. One day after baseline measurement of organic pain thresholds, rats were given cisplatin i.p. p. Injected. Cisplatin injections were given again on days 4, 8, and 12. Starting 1 hour after the first cisplatin injection, rats received 50 mg/kg DCUKA or vehicle via intragastric gavage twice daily for 14 days. After the last treatment (day 15), organic pain thresholds were tested again. Pain thresholds were then tested once a week for 4 weeks without further treatment.

Figure 16 shows that DCUKA can prevent the development of CFA-induced neuropathic pain.
Data shows the ratio of pre-organic pain thresholds to CFA baseline organic pain thresholds 60 hours after CFA treatment. CFA treatment significantly lowered pain threshold by approximately 70%. However, when animals received DCUKA daily before testing, thresholds did not decrease (P=0.16) and remained close to baseline pain thresholds. That is, DCUKA has the ability to prevent the development of inflammatory pain when given after administration of an inflammatory drug. Student's t-test was used to compare pain thresholds between groups, and paired t-tests were used to compare pain thresholds within groups.

Figure 17 illustrates that repeated DCUKA treatment over the period between cisplatin administration and pain testing prevented the development of pain in a rat cisplatin-induced neuropathic pain model. Data are expressed as mean ± SEM of organic pain threshold (paw withdrawal threshold). Injection of cisplatin resulted in a significant reduction in organic pain thresholds over many days in chronic vehicle-treated rats. With repeated DCUKA treatments, there was a significant reduction in pain threshold compared to baseline before cisplatin administration. This result indicates that DCUKA has the ability to prevent the development of chemotherapy-induced neuropathic pain, which is obtained after administration of chemotherapeutic agents.

A two-way repeated measures analysis of variance revealed a statistically significant difference (P=0.023) between the two treatments, DCUKA and vehicle. Individual P values shown in the graphs are for DCUKA versus vehicle and were calculated by the multiple comparison method. Also, significant differences were detected in pain thresholds in the cisplatin and vehicle groups (days 15, 19, 25, and 32) compared to day 0 before cisplatin injection, but not on day 0 before cisplatin injection. There were no significant differences in pain thresholds between the cisplatin and DCUKA groups compared to the values.

Preferred embodiments of this invention are described herein above, including the best mode known to the inventors for carrying out the invention. Variations of these preferred embodiments within the scope of the invention will be apparent to those skilled in the art upon reading the above description. Accordingly, this invention includes all modifications and equivalents of the subject matter as defined by the claims appended hereto. Furthermore, any combination of the above-described elements in all possible variations thereof is encompassed by the present invention, unless indicated otherwise herein or the context clearly dictates otherwise. .

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Claims (6)

A pharmaceutical composition for use in enhancing the effect of an analgesic compound in a patient suffering from chronic pain, the composition comprising: a pharmaceutically effective amount of:
(a) The following formula

During the ceremony:
R ⁷ is phenyl;
R ⁸ is phenyl:
E ¹ is -C(=O)OR ⁹ ;
R9 is H ^:
Each X ² and X ³ is independently a halogen
in the free acid form, in the free base form, or as a pharmacologically acceptable addition salt, and
(b) A pharmaceutical composition comprising an analgesic selected from the group consisting of oxycodone, methadone, tramadol, and mixtures thereof. The pharmaceutical composition according to claim 1, wherein the aminoquinoline compound is 5,7-dichloro-4-(3,3-diphenylureido)quinolone-2-carboxylic acid (DCUKA). A pharmaceutical composition for use in augmenting the effects of methadone in a patient suffering from chronic pain, the composition comprising: a pharmaceutically effective amount of methadone;
The following formula

During the ceremony:
R ⁷ is phenyl;
R ⁸ is phenyl:
E ¹ is -C(=O)OR ⁹ And;
R ⁹ is H:
each X ² and X ³ are independently halogen
A pharmaceutical composition comprising an aminoquinoline compound in free acid form, free base form, or as a pharmacologically acceptable addition salt. The pharmaceutical composition according to claim 3, wherein the aminoquinoline compound is 5,7-dichloro-4-(3,3-diphenylureido)quinolone-2-carboxylic acid (DCUKA). A pharmaceutical composition for use in augmenting the effects of tramadol in patients suffering from chronic pain, the composition comprising: a pharmaceutically effective amount of tramadol;
The following formula

During the ceremony:
R ⁷ is phenyl;
R ⁸ is phenyl:
E ¹ is -C(=O)OR ⁹ And;
R ⁹ is H:
each X ² and X ³ are independently halogen
A pharmaceutical composition comprising an aminoquinoline compound in free acid form, free base form, or as a pharmacologically acceptable addition salt. The pharmaceutical composition according to claim 5, wherein the aminoquinoline compound is 5,7-dichloro-4-(3,3-diphenylureido)quinolone-2-carboxylic acid (DCUKA).

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