Method of treating pain using topical naproxen and pregabalin conjugate formulations

Abstract

Described herein are method of treating neuropathic pain using topical naproxen and pregabalin conjugate formulations.

Description

METHOD OF TREATING PAIN USING TOPICAE NAPROXEN AND PREGABALINCONJUGATE FORMUEATIONSCROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 653,165 filed May 29, 2024; which is hereby incorporated by reference in its entirety.BACKGROUND

[0002] A number of treatments involving the administration of single drugs are currently recommended for relief of pain including neurological pain. The single administration of narcotic analgesics, gamma (y)-aminobutyric acid (GABA) analogs such as gabapentin, pregabalin and baclofen, antidepressants, and non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to display pain alleviating properties in the clinic and in various animal models.SUMMARY OF THE INVENTION

[0003] Disclosed herein is a method of reducing pain associated with a disease or disorder in a subject in need thereof; the method comprising topically administering a compound that is (3S)-3-((((l-(((S)-2-(6- methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid:

[0004] In some embodiments, the compound is (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :

[0005] In some embodiments, the compound is (S)-3-(((((R)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :

[0006] In some embodiments, the compound penetrates into deep tissues following topical administration of the compound.

[0007] In some embodiments, the compound penetrates into subcutaneous tissues following topical administration of the compound.

[0008] In some embodiments, the compound penetrates into muscle layer following topical administration of the compound.

[0009] In some embodiments, the compound penetrates into tendons following topical administration of the compound.

[0010] In some embodiments, the compound penetrates into the nerves following topical administration of the compound.

[0011] In some embodiments, the compound cleaves to release naproxen and pregabalin into deep tissues following topical administration of the compound.

[0012] In some embodiments, the compound cleaves to release naproxen and pregabalin into subcutaneous tissues following topical administration of the compound.

[0013] In some embodiments, the compound cleaves to release naproxen and pregabalin into muscle layer following topical administration of the compound.

[0014] In some embodiments, the compound cleaves to release naproxen and pregabalin into tendons following topical administration of the compound.

[0015] In some embodiments, the compound cleaves to release naproxen and pregabalin into nerves following topical administration of the compound.

[0016] In some embodiments, the disease or disorder is migraine.

[0017] In some embodiments, the migraine is episodic migraine, chronic migraine, hemiplegic migraine, retinal migraine, menstrual migraine, migraine-associated vertigo, migraine with aura, or migraine without aura.

[0018] In some embodiments, the compound administration reduces muscle tension, muscle tenderness, and / or trigeminal nerve excitation, thereby reducing the pain associated with the migraine.

[0019] In some embodiments, the pain is neck pain.

[0020] In some embodiments, the neck pain is caused by paraspinal muscle spasm.

[0021] In some embodiments, the neck pain is caused by the compression of spinal nerves.

[0022] In some embodiments, the disease or disorder is cervical radiculopathy.

[0023] In some embodiments, the pain is back pain.

[0024] In some embodiments, the back pain is caused by sciatica.

[0025] In some embodiments, the disease or disorder is frozen shoulder.

[0026] In some embodiments, the disease or disorder is rotator cuff tearing.

[0027] In some embodiments, the rotator cuff tearing involves the joint capsule.

[0028] In some embodiments, the disease or disorder is deep tendonitis.

[0029] In some embodiments, the disease or disorder is muscle tearing.

[0030] In some embodiments, the disease or disorder is tennis elbow.

[0031] In some embodiments, the disease or disorder is peripheral nerve entrapment.

[0032] In some embodiments, the peripheral nerve entrapment is cubital tunnel syndrome, carpal tunnel syndrome, Guyon’s cannel syndrome, or tarsal tunnel syndrome.

[0033] In some embodiments, the disease or disorder is plantar fasciitis.

[0034] In some embodiments, the disease or disorder is rheumatoid arthritis.

[0035] In some embodiments, the pain is joint pain.

[0036] In some embodiments, the compound penetrates into the epidermis following topical administration of the compound.

[0037] In some embodiments, the compound penetrates into the dermis following topical administration of the compound.

[0038] In some embodiments, the compound cleaves to release naproxen and pregabalin into the epidermis following topical administration of the compound.

[0039] In some embodiments, the compound cleaves to release naproxen and pregabalin into the dermis following topical administration of the compound.

[0040] In some embodiments, the pain is neuralgia.

[0041] In some embodiments, the neuralgia is trigeminal neuralgia.

[0042] In some embodiments, the neuralgia is postherpetic neuralgia.

[0043] In some embodiments, the neuralgia is diabetic peripheral neuralgia.

[0044] In some embodiments, the disease or disorder is neuropathy.

[0045] In some embodiments, the disease or disorder is small fiber neuropathy.

[0046] In some embodiments, the pain is scar pain.

[0047] Also disclosed herein is a method of preventing a migraine episode in a subject in need thereof; the method comprising topically administering a compound that is (3S)-3-((((l-(((S)-2-(6- methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid:

[0048] In some embodiments, the compound is (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :

[0049] In some embodiments, the compound is (S)-3-(((((R)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :

[0050] In some embodiments, the compound penetrates into deep tissues following topical administration of the compound.

[0051] In some embodiments, the compound penetrates into subcutaneous tissues following topical administration of the compound.

[0052] In some embodiments, the compound penetrates into muscle layer following topical administration of the compound.

[0053] In some embodiments, the compound penetrates into tendons following topical administration of the compound.

[0054] In some embodiments, the compound penetrates into the nerves following topical administration of the compound.

[0055] In some embodiments, the compound cleaves to release naproxen and pregabalin into deep tissues following topical administration of the compound.

[0056] In some embodiments, the compound cleaves to release naproxen and pregabalin into subcutaneous tissues following topical administration of the compound.

[0057] In some embodiments, the compound cleaves to release naproxen and pregabalin into muscle layer following topical administration of the compound.

[0058] In some embodiments, the compound cleaves to release naproxen and pregabalin into tendons following topical administration of the compound.

[0059] In some embodiments, the compound cleaves to release naproxen and pregabalin into nerves following topical administration of the compound.

[0060] In some embodiments, the disease or disorder is migraine.

[0061] In some embodiments, the migraine is episodic migraine, chronic migraine, hemiplegic migraine, retinal migraine, menstrual migraine, migraine-associated vertigo, migraine with aura, or migraine without aura.

[0062] In some embodiments, the compound administration reduces muscle tension, muscle tenderness, and / or trigeminal nerve excitation, thereby preventing the migraine.

[0063] In some embodiments, the compound is administered once a day. In some embodiments, the compound is administered not more than once a day. In some embodiments, the compound is administered twice a day. In some embodiments, the compound is administered not more than twice a day. In some embodiments, the compound is administered thrice a day. In some embodiments, the compound is administered not more than thrice a day.BRIEF DESCRIPTION OF THE FIGURES

[0064] The novel features of the disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosure are utilized, and the accompanying drawings of which:

[0065] FIG. 1 graphs patient assessment of pain, stiffness, and physical function after Compound 1 topical application compared to a placebo.

[0066] FIG. 2 graphs patient daily walking pain after use of Compound 1.

[0067] FIG. 3 graphs patient sleep quality after use of Compound 1.

[0068] FIG. 4 graphs patient global impression of change (PGIC) after use of Compound 1.

[0069] FIG. 5 graph assessment of patient pain, stiffness, physical function using painDETECT tool to dichotomize into nociceptive and neuropathic pain, after use of Compound 1.

[0070] FIG. 6A shows the mean tissues (comeum, dermis, epidermis, subcutaneous and muscle) concentration profiles of Compound 1 in male Barna minipigs following single dermal application, 10 cm x 10 cm administration of Compound 1 topical gel at 3.5 mL / animal Gel (175 mg / animal API)

[0071] FIG. 6B shows the mean tissues (comeum, dermis, epidermis, subcutaneous and muscle) concentration profiles of Pregabalin (XC001) in male Bama minipigs following single dermal application, 10 cm x 10 cm administration of Compound 1 topical gel at 3.5 mL / animal Gel (175 mg / animal API).

[0072] FIG. 6C shows the mean tissues (comeum, dermis, epidermis, subcutaneous and muscle) concentration profiles of Naproxen (XC002) in male Bama minipigs following single dermal application, 10 cm x 10 cm administration of Compound 1 topical gel at 3.5 mL / animal Gel (175 mg / animal API).

[0073] FIG. 7A shows the mean tissues (comeum, dermis, epidermis, subcutaneous and muscle) concentration profiles of Compound 2 in male Bama minipigs following single dermal application, 10 cm x 10 cm administration of Compound 2 topical gel at 3.5 mL / animal Gel (175 mg / animal API).

[0074] FIG. 7B shows the mean tissues (comeum, dermis, epidermis, subcutaneous and muscle) concentration profiles of pregabalin (XC001) in male Bama minipigs following single dermal application, 10 cm x 10 cm administration of Compound 2 topical gel at 3.5 mL / animal Gel 175 mg / animal API).

[0075] FIG. 7C shows the tissues (comeum, dermis, epidermis, subcutaneous and muscle) concentration profiles of Naproxen (XC002) in male Bama minipigs following single dermal application, 10 cm x 10 cm administration of Compound 2 topical gel at 3.5 mL / animal Gel (175 mg / animal API).DETAILED DESCRIPTION

[0076] A number of treatments involving the administration of single drugs are currently recommended for relief of pain including neurological pain. The single administration of narcotic analgesics, gamma (y)-aminobutyric acid (GABA) analogs such as gabapentin, pregabalin and baclofen, antidepressants, and non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to display pain alleviating properties in the clinic and in various animal models.

[0077] Despite the benefits derived from the current single drug pain relief regimens, these regimens have disadvantages. One area of concern relates to the incidence of unwanted side effects caused by many of the pain treatment regimens available today. Narcotic analgesics, such as morphine, are sparingly prescribed for chronic pain because of the well-known addictive effects and central nervous system (CNS) side effects and gastrointestinal side effects resulting from their single administration.

[0078] Another concern of the current pain treatment regimens relates to their effectiveness. Many single active ingredients such as antidepressant agents or GABA analogs employed in current pain relief regimens cannot achieve adequate pain alleviation even at their maximum approved therapeutic doses in certain severe pain states. In addition to not achieving adequate pain alleviation, increasing the drug dose may produce an increase in unwanted side effects such as cognitive impairment, dizziness, somnolence, nausea, and constipation.

[0079] Furthermore, other concerns of GABA analogs and many narcotic analgesics relate to their less favorable pharmacokinetic and physiological properties. Many orally administrated opioid molecules are extensively metabolized by digestive organs before reaching systemic circulation. Rapid systemic clearance and saturable absorption of some of the GABA analogs have limited these drugs to reach their full potential in treatment of pain and other CNS disorders. These sub-optimal properties often lead to less than adequate efficacy and unwanted side effects in patients.

[0080] Additionally, the extreme hydrophilicity of GABA analogs such as pregabalin with log P of -1.34 prevents their topical use. The desired characteristics for topical dosing are 1) skin penetration; 2) stay at local tissue maintaining therapeutic drug concentration without diffusing away; 3) deeper penetration to reach the tissues, e.g., muscle, etc.

[0081] Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for the management of pain often as first line therapy. Naproxen, approved by the United States (US) Food and Drug Administration (FDA) in 1976 and approved as Over-the-Counter (OTC) drug in 1994 is one of the most commonly used NSAIDs for the management of both acute and chronic pain. Though generally well tolerated, the oral use of NSAIDs such as naproxen with systemic exposure is often associated with serious gastrointestinal (GI) side effects such as ulcers or bleeding (Aleve USPI ref; Kyremateng 2019; Solomon 2017).

[0082] In view of these concerns, it is evident that there is a need for an improved pain regimen that provides an improved therapeutic benefit (i.e., reduced severity and / or frequency of pain) and / or reduces the incidence of unwanted side effects caused by many of the current regimens. In addition, improving pharmacokinetic profile of GABA analogs will also lead to more customized dosing regimens accordingto patients’ need. Furthermore, topical administration of NSAIDs via naproxen will eliminate gastrointestinal (GI) and systemic exposure and improve overall safety.

[0083] Neuropathic pain is actual injury to the nerves and nervous system itself. Neuropathic pain, also known as nerve pain, is a type of chronic pain that occurs when nerves in the central nervous system become injured or damaged. Neuropathic Pain is a complex, chronic pain state that usually is accompanied by tissue injury or damage. In neuropathic pain, the nerve fibers themselves might be damaged, dysfunctional, or injured. These damaged nerve fibers send out pain signals when there might, in fact, be no actual tissue injury, other than to the nerve fibers. Nerve fiber injury can include a change in nerve function both at the site of injury and areas around the injury.

[0084] Naproxen is marketed products for the treatment of various types of pain (due to rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, tendinitis, bursitis, and acute gout) and pregabalin is marketed for the treatment of neuropathic pain, neuralgia, and fibromyalgia. Naproxen was initially approved by the United States (US) Food and Drug Administration (FDA) in 1976 and approved as over- the-counter (OTC) drug in 1994. Naproxen is a propionic acid derivative related to the arylacetic acid group of non-steroidal anti-inflammatory drugs (NSAIDs). Uike other NSAIDs, naproxen non- selectively and reversibly inhibits both COX-1 and COX-2 enzymes, resulting in the inhibition of prostaglandin synthesis and leukocyte activation. Through inhibiting COX- 1 / 2, naproxen induces an antiinflammatory and analgesic effect.

[0085] Pregabalin was initially approved by the US FDA in 2004, and generic versions are available since 2018. The topical formulation of naproxen that aimed to delivery naproxen topically has been developed to reduce the side effects and improving patient compliance (Patwardhan et al. 2017). Topical formulation of naproxen gel 10% w / v (Momendol Gel) is approved in several European countries. Similarly, the various product formulation development studies for pregabalin were completed to develop pregabalin controlled transdermal alternative to the conventional oral route (Arafa and Ayoub 2017 Arafa and Ayoub 2017; Bhatia et al. 2012) to minimize its CNS side effects. It could be a useful treatment option to avoid or minimize the central nervous system (CNS)-mediated side effects of orally administered pregabalin (Fukasawa et al. 2014). However, there is no topical pregabalin product on market thus far likely due to its hydrophilic chemical nature making topical delivery of pregabalin very challenging.

[0086] Multimodal therapeutic approaches for pain are recommended to minimize the adverse effects of individual drugs as well as to target different mechanisms of pain, including nociception, inflammation, and neuropathic (Finnerup 2019; American Pain Society monograph on pain; Hsu et al. 2019). Using such an approach may lead to better efficacy and lower opioid use for pain management in both acute and chronic pain syndromes. Addition of pregabalin, an agent known to target neuropathic pain to a NSAID may result in improved pain control in both acute (Wang et al. 2010, bunionectomy model) and chronic pain (Sofat et al. 2017 - hand osteoarthritis, Derry et al 2017-acute and chronic neuropathic pain, Eambrechts et al. 2013 - chronic post thoracotomy pain).

[0087] Described herein are topical formulations which are stable, non-aggregating suspensions of the Compound 1 or Compound 2, which enable the delivery of Compound 1 or Compound 2 for the effective topical delivery of the two active metabolites, pregabalin and naproxen.

[0088] (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid is a drug conjugate of pregabalin and naproxen. This drug conjugate is being developed for the management of both acute and chronic pain syndromes. Pre-clinical animal models have demonstrated improved efficacy with drug conjugate for pain and inflammation compared with naproxen alone. Topical (S)-3-(((((S)-l-(((S)-2-(6- methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid is expected to fulfill an unmet clinical need for improved management of both acute and chronic pain and reduce the need for opioids. As the naproxen and pregabalin are covalently bound by a linker moiety, while in the gastrointestinal (GI) track, there may be significant reduction in GI issues from minimal exposure of the gut to the free naproxen and free pregabalin.Compound 1

[0089] Compound 1 is (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :

[0090] In some embodiments, Compound 1 has a faster enzymatic cleavage as compared to Compound 2. In some embodiments, the faster enzymatic cleavage of Compound 1, as compared to Compound 2, provides higher amount of pregabalin and naproxen in skin and local muscle tissues. In some embodiments, Compound 1 has a better topical permeability as compared to Compound 2.Compound 2

[0091] Compound 2 is (S)-3-(((((R)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :

[0092] Pregabalin is (S)-3-(aminomethyl)-5-methylhexanoic acid

[0093] Naproxen is (S)-2-(6-methoxynaphthalen-2-yl)propanoic acidDefinitions

[0094] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs.

[0095] As used in the specification and claims, the singular form “a”, “an” and “the” includes plural references unless the context clearly dictates otherwise.

[0096] “Drug conjugate” refers to the biologically active drugs linked by chemical linkers with labile chemical bonds. Typically, the linker will be attached to the drugs via bond(s) that are cleaved by enzymatic or non-enzymatic means in vivo.

[0097] ‘ ‘Solvate” refers to a compound (e.g., a compound as described herein or a pharmaceutically acceptable salt thereof) in physical association with one or more molecules of a pharmaceutically acceptable solvent.Pharmaceutical Compositions

[0098] Described herein are formulations (e.g., topical formulation) for delivery of the active pharmaceutical ingredients (API; e.g., Compound 1, Compound 2) to specific sites or local sites for directed therapeutic effects. In some embodiments, a directed therapeutic effect includes, but is not limited to, relief of pain. Described herein are formulations comprising Compound 1 or Compound 2 and one or more excipients (e.g., a penetration enhancer, a preservative, a solvent / solubilizing agent, a suspending agent a pH adjusting agent). Without wishing to be bound to any theory, an excipient in a formulation described herein do not interfere with binding of the Compound 1 or Compound 2 active site of cleaving enzyme or in any other way interfere with the enzymatic process to cleave Compound 1 or Compound 2 into pregabalin and naproxen.

[0099] Described herein are topical formulations of compounds described herein. Exemplary topical formulations include, but are not limited to, gels (e.g., hydrogels), creams, suspensions, or solutions (e.g., aqueous solutions).Method of Treating

[0100] Described herein are methods of reducing pain associated with a disease or disorder in a subject in need thereof. In some embodiments, topically administering a formulation or a compound described herein refers to application of the formulation or the compound to the skin of a subject. In some embodiments, the method comprises topically administering a formulation described herein or the compound that is (3S)-3-((((l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid. In some embodiments, the compound is (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acidIn some embodiments, the compound is (S)-3-(((((R)-l-(((S)-2-(6-methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5- methylhexanoic acid

[0101] Described herein are methods of reducing pain associated with a disease or disorder in a subject in need thereof, wherein the methods comprise topically administering the conjugates, Compound 1 or Compound 2, for the effective topical delivery of the two active metabolites, pregabalin and naproxen. In some embodiments, the conjugates, Compound 1 or Compound 2, ensure the presence of both active metabolites, pregabalin and naproxen, at same time in local tissue. In contrast, using a fixed dose combination formulation (comprising both pregabalin and naproxen) will not be able to be delivered in the same way due to the difference of their physiological and chemical properties.

[0102] In some embodiments, a formulation or a compound described herein penetrates into stratum comeum following topical administration of the formulation or the compound described herein. In some embodiments, a formulation or a compound described herein penetrates into deep tissues following topical administration of the formulation or the compound described herein. In some embodiments, a formulation or a compound described herein penetrates into subcutaneous tissues following topical administration of the formulation or the compound described herein. In some embodiments, a formulation or a compound described herein penetrates into a muscle layer following topical administration of the formulation or the compound described herein. In some embodiments, a formulation or a compound described herein penetrates into a tendon following topical administration of the formulation or the compound described herein. In some embodiments, a formulation or a compound described herein penetrates into the epidermis following topical administration of the formulation or the compound described herein. In some embodiments, a formulation or a compound described herein penetrates into the dermis following topical administration of the formulation or the compound described herein.

[0103] In some embodiments, a formulation or a compound described herein penetrates into a nerve following topical administration of the formulation or the compound described herein. In some embodiment, a nerve can include any component thereof, included, but not limited to axons, dendrites, perineurium, epineurium, or synaptic terminals. In some embodiments, a nerve may be a sensory nerve or a motor nerve. In some embodiments, a formulation or a compound described herein cleaves to releaseinto a nerve following topical administration of the formulation or the compound described herein. In some embodiments, the pregabalin blocks voltage gate calcium channel at pre -synaptic sites.

[0104] In some embodiments, a compound described herein cleaves to release naproxen and pregabalin on top of the skin following topical administration of a formulation or the compound described herein. In some embodiments, a compound described herein cleaves to release naproxen and pregabalin into the stratum comeum following topical administration of a formulation or the compound described herein. In some embodiments, a compound described herein cleaves to release naproxen and pregabalin into deep tissues following topical administration of a formulation or the compound described herein. In some embodiments, a compound described herein cleaves to release naproxen and pregabalin into subcutaneous tissues following topical administration of a formulation or the compound described herein. In some embodiments, a compound described herein cleaves to release naproxen and pregabalin into a muscle layer following topical administration of a formulation or the compound described herein. In some embodiments, a compound described herein cleaves to release naproxen and pregabalin into a tendon following topical administration of a formulation or the compound described herein. In some embodiments, a formulation or a compound described herein cleaves to release naproxen and pregabalin into the epidermis following topical administration of the formulation or the compound described herein. In some embodiments, a formulation or a compound described herein cleaves to release naproxen and pregabalin into the dermis following topical administration of the formulation or the compound described herein.

[0105] Described herein are methods of treating osteoarthritis. In some embodiments, osteoarthritis can refer to, but not limited to, the joint or sites around the joints. In some embodiments, the osteoarthritis is osteoarthritis of a knee, a hand, a shoulder, a wrist, an ankle, an elbow, a joint (e.g., temporomandibular joint (jaw), sacroiliac (pelvis)), a hip, the neck, back or lumbar vertebrate, or any part thereof. In some embodiments, the method comprises administering a formulation described herein topically to a knee, a hand, a shoulder, a wrist, an ankle, an elbow, a joint (e.g., temporomandibular joint, sacroiliac), a hip, the neck, back or lumbar vertebrate, or any part thereof. In some embodiments, the osteoarthritis is osteoarthritis of a knee. In some embodiments, the osteoarthritis is osteoarthritis of the back. In some embodiments, osteoarthritis can result in pain, such as, but not limited to, inflammatory nociceptive pain, neuropathic pain, and / or mixed pain phenotype.

[0106] In some embodiments, osteoarthritis is primary osteoarthritis or secondary osteoarthritis. Symptoms of osteoarthritis include, but are not limited to, joint pain, joint stiffness, lower movement of the joint, or grinding of the bones at the joint. In some embodiments, methods described herein relieves a pain associated with a symptom of osteoarthritis.

[0107] In some embodiments, a pain in a subject can arise from a knee, a hand, a shoulder, a wrist, an ankle, an elbow, a joint (e.g., temporomandibular joint (jaw), sacroiliac (pelvis)), a hip, the neck, back or lumbar vertebrate, or any part thereof of the subject. In some embodiments, a disease or disorder is temporomandibular joint syndrome (TMJ).

[0108] In some embodiments, a disease or disorder is rheumatoid arthritis. In some embodiments, a pain in subject is joint pain from rheumatoid arthritis. In some embodiments, the pain associated from rheumatoid arthritis is caused by inflammation. In some embodiments, the joint pain from rheumatoid arthritis can arise from a knee j oint, a hand j oint, a should j oint, a wrist j oint, an ankle j oint, an elbow joint, a hip joint, or any part thereof.

[0109] In some embodiments, a pain in a subject is neck pain. In some embodiments, the neck pain is caused by a disease, an injury, a joint, a tissue, or a muscle. In some embodiments, the neck pain is acute neck pain. In some embodiments, the neck pain is caused by paraspinal muscle spasm. In some embodiments, the neck pain is caused by the compression of spinal nerves. In some embodiments, a pain is caused by entrapment of lumbar spinal nerve.

[0110] In some embodiments, a disease or disorder is peripheral nerve entrapment. In some embodiments, the peripheral nerve entrapment is cubital tunnel syndrome, carpal tunnel syndrome, Guyon’s cannel syndrome, or tarsal tunnel syndrome.

[0111] In some embodiments, a disease or disorder is cervical radiculopathy. In some embodiments, a pain is caused by the entrapment of cervical spinal nerve. In some embodiments, a pain is caused a herniated disk or bone spurs of the vertebrae. In some embodiments, a pain is caused by entrapment of a peripheral nerve.

[0112] In some embodiments, a pain in subject is back pain. In some embodiments, the back pain is caused by a disease, an injury, a joint, a tissue, or a muscle. In some embodiments, the back pain is caused by sciatica. In some embodiments, the back pain is caused by inflammation, a herniated disk, or pressure on a sciatic nerve, or overgrowth of a bone.

[0113] In some embodiments, a pain in subject is shoulder pain. In some embodiments, the shoulder pain is caused by a disease, an injury, a joint, a tissue, or a muscle. In some embodiments, a disease or disorder is frozen shoulder. In some embodiments, a disease or disorder is rotator cuff tearing. In some embodiments, the rotator cuff tearing involves the joint capsule.

[0114] In some embodiments, a disease or disorder is deep tendonitis. In some embodiments, a disease or disorder is muscle tearing. In some embodiments, a disease or disorder is tennis elbow.

[0115] In some embodiments, a pain in subject is foot pain. In some embodiments, the foot pain is caused by a disease, an injury, a joint, a tissue, or a muscle. In some embodiments, a disease or disorder is plantar fasciitis. In some embodiments, the foot pain is heel pain. In some embodiments, the foot pain is caused by inflammation.

[0116] In some embodiments, a pain is located on the head of the subject. In some embodiments, the pain located on the head is caused by a disease, an injury, a joint, a tissue, or a muscle. In some embodiments, a pain in subject is neuralgia. In some embodiments, the neuralgia is trigeminal neuralgia. In some embodiments, the neuralgia is postherpetic neuralgia. In some embodiments, the neuralgia is diabetic peripheral neuralgia. In some embodiments, a disease or disorder is neuropathy. In some embodiments, a disease or disorder is small fiber neuropathy. In some embodiments, a pain in subject is scar pain.

[0117] In some embodiments, a disease or disorder is migraine. In some embodiments, a migraine is episodic migraine, chronic migraine, hemiplegic migraine, retinal migraine, menstrual migraine, migraine-associated vertigo, migraine with aura, or migraine without aura. In some embodiments, the migraine is a migraine with brainstem aura. In some embodiments, administration of a formulation or a compound described herein reduces muscle tension, muscle tenderness, and / or trigeminal nerve excitation. In some embodiments, reduction of muscle tension, muscle tenderness, and / or trigeminal nerve excitation results in reducing the pain associated with the migraine. In some embodiments, the migraine is vestibular migraine. In some embodiments, the migraine is a menstrual migraine. In some embodiments, a migraine is caused by an injury to the head or a symptom of an injury to the head (e.g., a concussion).

[0118] Described herein are methods of preventing a migraine episode in a subject in need thereof. In some embodiments, the method comprises topically administering a formulation described herein or a compound that is (3S)-3-((((l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :In some embodiments, the compound is (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5- methylhexanoic acidIn some embodiments, the compound is(S)-3-(((((R)-l-(((S)-2-(6-methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5- methylhexanoic acid

[0119] In some embodiments, a formulation or a compound described herein administration is applied to a diseased area on the subject or an area with pain. In some embodiments, a formulation or a compound described herein is administered once a day. In some embodiments, a formulation or a compound described herein is administered twice a day.

[0120] In some embodiments, a formulation or a compound described herein is administered twice a day. In some embodiments, a formulation or a compound described herein is administered thrice a day. In some embodiments, a formulation or a compound described herein is administered four times a day.

[0121] In some embodiments, a formulation or a compound described herein is administered not more than once a day. In some embodiments, a formulation or a compound described herein is administered not more than twice a day. In some embodiments, a formulation or a compound described herein is administered not more than thrice a day. In some embodiments, a formulation or a compound described herein is administered not more than 4 times a day.

[0122] In some embodiments, topically administering a formulation or a compound described herein provides controlled local administration of the compound and / or pregabalin and naproxen. In some embodiments, topically administering a formulation or a compound described herein does not result in any the compound and / or pregabalin and naproxen in the blood circulation or low amount of the compound and / or pregabalin and naproxen in the blood circulation. In some embodiments, topically administering a formulation or a compound described herein provides results in lower adverse effects compared to system exposure of the compound described herein or an oral formulation of the compound. In some embodiments, topically administering a formulation or a compound described herein results in lower amount of the compound and / or pregabalin and naproxen in systemic circulation provided to a subject.

[0123] In some embodiments, topically administering a formulation or a compound described herein act as a drug depot to provides a therapeutic effect (e.g., pain relief) for about 1 hour to 400 hours. In some embodiments, topically administering a formulation or a compound described herein provides a therapeutic effect (e.g., pain relief) for about 1 hour to 400 hours, about 1 hour to about 300 hours, about 1 hour to about 200 hours, about 1 hour to about 175 hours, about 1 hour to about 150 hours, about 1 bout to about 125 hours, about 1 hour to about 100 hours, about 1 hour to about 75 hours, about 1 hour to about 50 hours, about 1 hour to about 25 hours, about 10 hours to about 400 hours, about 10 hours to about 300 hours, about 10 hours to about 200 hours, about 10 hours to about 175 hours, about 10 hours to about 150 hours, about 10 hours to about 125 hours, about 10 hours to about 100 hours, about 10 hours to about 50 hours, or any range in between, at the administered site.

[0124] While preferred embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.EXAMPLES

[0125] The following examples are provided to further illustrate some embodiments of the present disclosure, but are not intended to limit the scope of the disclosure; it will be understood by their exemplary nature that other procedures, methodologies, or techniques known to those skilled in the art may alternatively be used.Example 1: Single Topical Application of Compound 1 and Compound 2

[0126] This study provides exemplary data on the pharmacokinetic (PK) properties of the drug conjugates Compound 1, Compound 2, and their active metabolites, Pregabalin and Naproxen, following single topical application of Compound 1 and Compound 2 hydrogel in male Barna minipigs (formulation: about 30% of each: IPA, water, propylene glycol with 0.8% Noveon with pH ~5).

[0127] Twenty-four naive Barna minipigs were divided into two groups with 12 animals / group. Animals in Group 1 were topically administered with 5% Compound 1 Gel by single topical application, 10 cm x 10 cm at 3.5 mL / animal Gel (5% w / w, 175 mg API of per animal). Animals in Group 2 were topically administered with 5% Compound 2 Gel by single topical application, 10 cm x 10 cm at 3.5 mL / animal Gel (5% w / w, 175 mg of API per animal). Blood samples were collected at 1, 4, 12, 24, 36, 48, 72 and 96 hours post-dose for Groups 1 and 2. Comeum, epidermis, dermis, subcutaneous tissue (including fat) and local muscle samples were collected at 1, 4 (local muscle), 12, 24 (local muscle), 72 (local muscle) and 96 hours post-dose for Groups 1 and 2. Concentrations of Compound 1, Compound 2, Pregabalin and Naproxen in blood, comeum, epidermis, dermis, subcutaneous tissue (including fat) and muscle samples were determined by an LC-MS / MS method.Table 1. Blood PK Parameters After Single Topical Administration of Compound 1 & Compound 2 in MinipigND : not determinedTable 2. Skin PK Parameters After Single Topical Administration of Compound 1 in Minipig“*” The adjusted linear regression coefficient of the concentration value on the terminal phase is less than0.9, TI / 2 might not be accurately estimated.# ng / mL and ng h / mL for the ComeumTable 3. Skin PK Parameters After Single Topical Administration of Compound 2 in Minipig“*” The adjusted linear regression coefficient of the concentration value on the terminal phase is less than0.9, TI / 2 might not be accurately estimated.# ng / mL and ng h / mL for the ComeumTable 4. Skin Mean PK Parameters of Pregabalin After Single Topical Administration of Compound 1 or Compound 2 in MinipigGroup 1: Compound 1; Group 2: Compound 2;ND: not detected (Cmax) or not determined (Tmax, T1 / 2, AUCs);“*” The adjusted linear regression coefficient of the concentration value on the terminal phase is less than 0.9, T1 / 2 might not be accurately estimated.# ng / mL and ng h / mL for the ComeumTable 5. Skin Mean PK Parameters of Naproxen After Single Topical Administration of Compound 1 orCompound 2 in Minipig“ND” means not determined (Parameters not determined due to inadequately defined terminal elimination phase)“*” The adjusted linear regression coefficient of the concentration value on the terminal phase is less than 0.9, T1 / 2 might not be accurately estimated.# ng / mL and ng h / mL for the Comeum

[0128] Topical administration of Compound 1 was able to deliver pregabalin and naproxen in the comeum, epidermis, dermis, subcutaneous tissue, and muscle at a higher concentration than topical administration of Compound 2. For example, topical administration of Compound 1 was able to deliver pregabalin to the muscle while topical administration of Compound 2 did not.

[0129] Following a single topical administration of Compound 1 (5% w / w) and Compound 2 (5% w / w) at 175 mg of API per animal in male Barna minipigs, the AUCo-iast values of Compound 1 and Compound 2 were 1458 and 1648 ng / mL, in blood respectively. The Cmaxvalues were 57.8 and 149 ng / g (cleave slower), while Cmaxwas reached at 50.0 and 38.0 h, respectively.

[0130] Following a single topical administration of Compound 1 (5% w / w) and Compound 2 (5% w / w) at 175 mg of API per animal in male Barna minipigs, the AUCo-iast values of Naproxen were 527±479 and 323 ng h / mL in blood, respectively. The Cmaxvalues were 8.36±7.57 and 5.96 ng / mL in blood, while Cmaxwas reached at 64.0±13.9 and 60.0 h in blood, respectively.

[0131] After a single topical administration of Compound 1 (5% w / w) at 175 mg of API per animal in male Barna minipigs, Compound 1 was found in all tissues until the end of the study (96 hours post dosing except 72 hours for muscle). The highest tissue exposure (AUCo-iast) was observed in epidermis (2032141 ng h / g) and dermis (1347340 ng h / g), followed by muscle (682757 ng h / g), subcutaneous (330549 ng h / g) and comeum (46235 ng h / mL).

[0132] After a single topical administration of Compound 2 (5% w / w) at 175 mg of API per animal in male Barna minipigs, Compound 2 was found in all tissues until the end of the study (96 hours post dosing except 72 hours for muscle). The highest tissue exposure (AUCo-iast) was observed in epidermis (1639204 ng h / g) and dermis (1364835 ng h / g), followed by muscle (1054117 ng h / g), subcutaneous (463269 ng h / g) and comeum (49193 ng h / mL).

[0133] After a single topical administration of Compound 1 at 175 mg of API per animal in male Barna minipigs, pregabalin (XC001) was found in all tissues until the end of the study (96 hours post dosing except 72 hours for muscle). The highest tissue exposure (AUCo-iast) was observed in dermis (107708 ng h / g) and epidermis (68422 ng h / g), followed by subcutaneous (35216 ng h / g), muscle (12143 ng h / g) and comeum (187 ng h / mL).

[0134] After a single topical administration of Compound 2 at 175 mg of API per animal in male Barna minipigs, pregabalin (XC001) was found in all tissues except muscle until the end of the study. The highest tissue exposure (AUCo-iast) was observed in epidermis (20896 ng h / g) and dermis (14909 ng h / g), followed by subcutaneous (7777 ng h / g) and comeum (71.9 ng h / mL). No pregabalin was found in muscle. The result suggested that Compound 1 offers a distinct advantage over Compound 2 by achieving significantly higher pregabalin exposure in muscle tissue (AUCo-iast: 12,143 ng h / g), whereas Compound 2 resulted in no detectable pregabalin in muscle, indicating superior tissue penetration and potential efficacy in deep musculoskeletal pain.

[0135] After a single topical administration of Compound 1 at 175 mg of API per animal in male Barna minipigs, naproxen was found in all tissues until the end of the study (96 hours post dosing except 72 hours for muscle). The highest tissue exposure (AUCo-iast) was observed in dermis (45930 ng h / g) and epidermis (41269 ng h / g), followed by subcutaneous (20313 ng h / g), muscle (7226 ng h / g) and comeum (202 ng h / mL).

[0136] After a single topical administration of Compound 2 at 175 mg of API per animal in male Barna minipigs, naproxen was found in all tissues until the end of the study (96 hours post dosing except 72hours for muscle). The highest tissue exposure (AUCo-iast) was observed in epidermis (53959 ng h / g) and dermis (21410 ng h / g), followed by muscle (4959 ng h / g, lower than from compound 1), subcutaneous (3709 ng h / g) and comeum (333 ng h / mU).

[0137] There was no evident difference between Compound 1 and Compound 2 in tissues following by single topical administration to male Barna minipigs at 175 mg / animal with the AUCo-iast of Compound 1 in comeum, epidermis, dermis, subcutaneous and muscle tissue 0.94, 1.24, 0.99, 0.71 and 0.65 fold of Compound 2, separately. The Cmax of Compound 1 in comeum, epidermis, dermis, subcutaneous and muscle tissue was 0.98, 1.58, 1.05, 0.52 and 1.65 fold of Compound 2, separately.

[0138] The systemic exposure (AUCo-iast and Cmax) of metabolite pregabalin in tissues following by single topical administration of Compound 1 to male Barna minipigs at 175 mg / animal were higher than that administered with Compound 2. The AUCo-iast of pregabalin of minipigs administered with Compound 1 in comeum, epidermis, dermis and subcutaneous tissue were 2.60, 3.27, 7.22 and 4.53 fold of Compound 2, separately. The Cmax of pregabalin of minipigs administered with Compound 1 in comeum, epidermis, dermis and subcutaneous tissue were 5.68, 3.71, 11.69 and 13.55 fold of Compound 2, separately. The AUCo-iast of pregabalin in muscle was not available due to inadequately defined terminal elimination phase and not compared here.

[0139] The systemic exposure (AUCo-iast and Cmax) of metabolite naproxen in tissues following by single topical administration of Compound 1 to male Barna minipigs at 175 mg / animal were higher than that administered with Compound 2 (except comeum and epidermis). The AUCo-iast of pregabalin of minipigs administered with Compound 1 in comeum, epidermis, dermis, subcutaneous and muscle tissue were 0.61, 0.76, 2.15, 5.48 and 1.46 fold of Compound 2, separately. The Cmax of pregabalin of minipigs administered with Compound 1 in comeum, epidermis, dermis, subcutaneous and muscle tissue were 0.65, 0.71, 2.79, 6.27 and 3.39 fold of Compound 2, separately.

[0140] All animals tolerated the compound at the dosing levels during the entire course of the study. No adverse effect was observed during the in-life phase of the study.Table 6A. Drug Concentrations in Comeum, Epidermis, and Dermis Over 96 hrs After Single TopicalAdministration of Compound 1 in MinipigNA: Not Available;ND: Not DetectedTable 6B. Drug Concentrations in Subcutaneous Tissue and Muscle Over 96 hrs After Single TopicalAdministration of Compound 1 in MinipigNA: Not Available;ND: Not Detected

[0141] The corresponding graphs are shown in FIG. 6A, FIG. 6B, and FIG. 6C. For each time point, the first bar corresponds to the mean comeum, the second bar corresponds to the mean dermis, the third bar corresponds to the mean epidermis, the 4thbar corresponds to the mean muscle, and the fifth bar corresponds to the mean subcutaneous tissue. Note that there was no muscle measurements at 1, 12, and 96 hrs.Table 7A. Skin PK Parameters of Naproxen & Pregabalin in Comeum, Epidermis, and Dermis After 5 days of Oral Administration of Compound 2 (28.5 mg / kg, BID)ND: Not Determined;# ng / mL and ng h / mL for the ComeumTable 7B. Skin PK Parameters of Naproxen & Pregabalin in Subcutaneous Tissue and Muscle After 5 days of Oral Administration of Compound 2 (28.5 mg / kg, BID)ND: Not Determined# ng / mL and ng h / mL for the Comeum

[0142] The corresponding graphs are shown in FIG. 7A, FIG. 7B, and FIG. 7C. For each time point, the first bar corresponds to the mean comeum, the second bar corresponds to the mean dermis, the third bar corresponds to the mean epidermis, the 4thbar corresponds to the mean muscle, and the fifth bar corresponds to the mean subcutaneous tissue. Note that there was no muscle measurements at 1, 12, and 96 hrs.Example 2: Skin Absorption and Penetration Compound 1 and Compound 2

[0143] This study provides exemplary data on the skin absorption and penetration of Compound 1 and Compound 2. The amounts of Compound 1 and Compound 2 as well as their respective metabolites (naproxen and pregabalin) absorbed in epidermis and dermis layers at 24 hr and penetrated into thereceptor medium at 2, 4, 8, and 24 hr time points were analyzed and reported using a Gottingen Minipig and dermatomed human cadaver skin model.

[0144] Voltaren gel was used as a control formulation, Compound 1 and Compound 2 were formulated separately into an aqueous gel-based formulation at 5% w / w and 10% w / w.FormulationHuman Skin

[0145] Dermatomed human cadaver skin tissue was procured from a tissue bank in the U.S. Two lots of the dermatomed skin tissue were received. Donor demographics: (average thickness: 717 pm): sex = male, age = 47, race = Caucasian, and anatomical site = abdomen; (average thickness: 765 pm): sex = female, age = 49, race = Caucasian, and anatomical site = abdomen. The thickness was measured using a digital snap-gage. Triplicate for each donor (N = 3 per donor). The tissue was received in dry ice packaging. It was stored at -20 °C until use.Frozen Gottingen Minipig Skin

[0146] Gottingen Minipig skin tissue was purchased from Marshall BioResources. Gottingen Minipig skin from back and flank was used. After euthanized, the skin tissues were collected and immediately snap-freeze in a freezer. The tissues were shipped to Zyleris on dry ice. The skin tissues were defatted and hair-trimmed. The thickness was measured using a digital snap gage as 1253 pm. The tissue was received in dry ice packaging. It was stored at -20 °C until use.In Vitro Skin Absorption and Penetration Study

[0147] The formulation screening study was carried out in Zyleris’ High-Throughput Screening (HTS) station. The skin tissue samples (after washed with lx PBS, pH 7.4) were mounted on diffusion cells in HTS station.

[0148] A total of 30 cells per skin model were used in the study. Each cell in the station has a diffusion area of 0.503 cm2(8 mm in diameter). Each individual cell is static Franz-Cell type. The receptor chamber was filled with 3.0 ml of 4% BSA in water, supplemented with 0.02% gentamicin sulfate, which was vigorously and continuously mixed. The temperature was maintained at 32±0.2 °C.

[0149] The tissue samples in the HTS cells were equilibrated at 32±0.2 °C for 1 hour before dosing.The samples were dosed at a level listed below using a positive displacement pipette. Each formulationwas run in six replicates (N=6) per skin model. A dosage of 7.5 pl per cell is equivalent to 15 mg / cm2of skin tissue.

[0150] At time points 2, 4, and 8 hr, entire receptor medium was collected and replaced with a fresh batch of receptor medium (pre-incubated at 32 °C). The samples collected from the receptor medium were processed and stored in a freezer and ready for analysis.

[0151] At 24hr, the skin tissues were removed from the cells. The tissue surface was carefully wiped with Q-tip wetted with distilled water, followed by wiping with dry Q-tip one time; then, wiped with Q- tip wetted with distilled water, followed by wiping with dry Q-tip one more time. Then, two cycles of tape -stripping were performed to remove residual formulation left on the skin surface (un-absorbed / un- penetrated).

[0152] Then, Scotch tape was used in tape-stripping process. The tape-stripping cycle was repeated for additional 15 times. It has been established in our laboratory that 15 -stripping-cycle is sufficient to completely remove the SC layer from human cadaver or pig skin tissue. The collected tape strips were discarded.

[0153] After removal of SC layer, skin was wetted with distilled water to aid separation of epidermis from dermis layer. Epidermis and dermis layer were separated mechanically. Surgical blade #21 was used to scrape epidermis off from dermis layer. The scraped-off epidermis layer was collected from the blade by wiping with lx PBS-wetted paper towels. The paper towels were combined and extracted with 4.0 ml of DMSO / acetonitrile at 50 / 50 (volume) at room temperature overnight under agitation using an orbit shaker. After extraction, the samples were collected and ready for analysis.

[0154] The remaining dermis layer was cut into small pieces and extracted with 4.0 ml of DMSO / acetonitrile at 50 / 50 (volume) at room temperature overnight under agitation using an orbit shaker. The supernatants were collected and ready for analysis.

[0155] The receptor medium at 24 hr was collected and analyzed.Table 8. In Vitro Skin Absorption and Penetration Study in Human Cadaver

[0156] The results show the amounts of Compound 1 and Compound 2 in the receptor medium were significantly lower than those in epidermis and dermis layers. This indicates that the absorbed Compound 1 and Compound 2 is mainly retained in the skin layers rather than quickly permeated into systemic circulation in the in vitro model.

[0157] Data from human skin indicate that the percentages of Compound 1 and Compound 2 in the epidermis and dermis layers are significantly higher than those of diclofenac (from Voltaren). In addition, the 10% gel (both Compound 1 and Compound 2) showed about the twice amount of retention in epidermis layer than the 5% gel. This may indicate that even at such a high API concentration, saturation of skin permeation of both Compound 1 and Compound 2 has not been reached yet, and both Compound 1 and Compound 2 may be very permeable.

[0158] Metabolization of both Compound 1 and Compound 2 are quite minor in epidermis and dermis layer. This may be due to minimal metabolic activities in cadaver skin tissues.

[0159] For Gottingen minipig skin, diclofenac shows slightly greater amounts of retention in epidermis and dermis than Compound 1 and Compound 2. In addition, the 10% gel (both Compound 1 and Compound 2) showed about same amount of retention in epidermis and dermis layer than the 5% gel. This indicated that saturation of skin permeation of both Compound 1 and Compound 2 may have been reached. The amounts permeated into the receptor medium for the pig skin were greater than the human skin, the difference may arise from differences between human and Gottingen minipig skin.

[0160] Metabolization of both Compound 1 and Compound 2 were minor in epidermis and dermis layer. The amount in the skin layers in the minipig model were about same as in the human cadaver model, suggesting minimal metabolic activities in the frozen minipig skin tissues.Conclusion:

[0161] Studies using human cadaver skin demonstrate that Compound 1 penetrates the skin but is retained in the epidermis and dermis, which is advantageous for local dosing (local accumulation). In contrast, Voltaren also penetrates human skin but passes through more quickly, resulting in lower retention and requiring more frequent application, four times a day (QID ).Example 3: Analgesic Effectiveness of Compound 2

[0162] This study provides exemplary data on the evaluated the analgesic effect of Compound 2 via topical administration of Compound 2 in the administration to rats having received the chronic constriction injury (CCI) surgery. As a control, pregabalin was administered orally.

[0163] 33 male Sprague -Dawley rats divided into the four groups listed below in Table 9.Table 9. Dosing and Administration of Compound 2 for Analgesic Effectiveness Evaluation

[0164] Pregabalin was prepared in 0.9% saline at a concentration of 6 mg / ml, while Compound 2 was formulated into an aqueous gel base (0.8% Noveon, 33% propylene glycol, 33% IPA, water (q.s), at 5% concentration).

[0165] The standard CCI Surgery was performed on day 0 and all dosing regimens described were administered on days 14 - 20 post-surgery (for 7 days). Group 2 (Oral) was administered 5 mL / kg once a day from days 14 to day 20 post-surgery. Groups 1, 3, and 4 (topical) were administered 1 mL / kg twice a day from day 14 to day 20 post-surgery. Groups 1, 3 and 4 were topically administered to a 10 x 10 cm shaved region on the back of the animal.

[0166] Animals in Groups 1, 2, and 3 were tested by the Von Frey and Weigh Bearing analgesic tests. They were tested at various time points during the 7 testing days.

[0167] Animals in Group 4 had blood collected for measurement of Compound 2 in the plasma at various time points as show below during the 7 testing days. The plasma samples were assayed by LC- MS / MS for Compound 2, pregabalin and naproxen.Table 10. Compound 2 values in the plasma samples from Group 4Table 11. Naproxen values in the plasma samples from Group 4Table 12. Pregabalin values in the plasma samples from Group 4Von Frey Test for Compound 2

[0168] The Von Frey Test was used to measure the analgesic effect of a test compound.

[0169] Mechanical allodynia of the left hind paw was measured during the course of study by determining withdrawal thresholds to an electronic Von Frey filament. The filament was applied perpendicularly to the plantar surface of the paw with increasing force. The force required to induce a reflex paw withdrawal were calculated by taking the average of 2 repeated stimuli (in g), which induced a reflex paw withdrawal.Results

[0170] At each testing session, the animals received either pregabalin (orally), Compound 2 (topically), or placebo (topical). More increased pressure was required to elicit a response when compared to the most recent baseline (just prior to dosing). The oral dosing with pregabalin and topical dosing with Compound 2 showed very similar analgesic effects. There was little or no analgesic effect from the topical administration of the placebo.Dynamic Weight Bearing Test for Compound 2

[0171] Rats distributed body weight unequally on CCI-induction and contra-lateral paws, which were measured by weight balance changing instrument. The animals were tested to register the weight loadexerted by the hind paws by means of force plate inserted in the floor. The mean weight bearing (in g) between dose-infection paw and contra-lateral paw were determined in 10 seconds.Results

[0172] At each testing session, the animals received either pregabalin (orally), Compound 2 (topically), placebo (topical). More even weight distribution was observed when compared to the most recent baseline (just prior to dosing). Even weight distribution is indicative of less pain, that is, less favoring a particular body part. The oral dosing with pregabalin and topical dosing with Compound 2 showed very similar analgesic effects. There was little or no analgesic effect from the topical administration of the placebo.Example 4: Analgesic Effectiveness of Compound 1

[0173] This study provides exemplary data on the evaluated the analgesic effect of Compound 1 via topical administration of Compound 1 in the administration to rats having received the chronic constriction injury (CCI) surgery. As a control, pregabalin was administered orally.

[0174] The study groups and treatment per group is shown in Table 13.Table 13: Dosing and Administration of Compound 1 for Analgesic Effectiveness Evaluation

[0175] Pregabalin was prepared in 0.9% saline at a concentration of 6 mg / ml, while Compound 1 was formulated into an aqueous gel base (0.8% Noveon, 33% propylene glycol, 33% IPA, water (q.s)) at concentrations of 5% (w / w) and 10% (w / w).

[0176] Plasma PK results indicated that the metabolite concentration of Compound 1 (pregabalin and naproxen) were in a dose dependent fashion.Table 14: Compound 1 blood concentration-time data in Group 3, 5% (50mg / mL)Table 15: Compound 1 blood concentration-time data in Group 4, 10% (lOOmg / mL)Table 16: Pregabalin blood concentration-time data in Group 3, 5% (50mg / mL)Table 17: Pregabalin blood concentration-time data in Group 4, 10% (IQOmg / mL)Table 18: Naproxen blood concentration-time data in Group 3, 5% (50mg / mL)Table 19: Naproxen blood concentration-time data in Group 4, 10% (IQOmg / mL)Von Frey Test for Compound 1

[0177] The Von Frey Test was used to measure the analgesic effect of a test compound.

[0178] Mechanical allodynia of the left hind paw was measured during the course of study by determining withdrawal thresholds to an electronic Von Frey filament. The filament was applied perpendicularly to the plantar surface of the paw with increasing force. The force required to induce a reflex paw withdrawal were calculated by taking the average of 2 repeated stimuli (in g), which induced a reflex paw withdrawal.Dynamic Weight Bearing Test for Compound 1

[0179] Rats distributed body weight unequally on CCI-induction and contra-lateral paws, which were measured by weight balance changing instrument. The animals were tested to register the weight load exerted by the hind paws by means of force plate inserted in the floor. The mean weight bearing (in g) between dose-infection paw and contra-lateral paw were determined in 10 seconds.The Results from the Von Frey Test for Compound 1

[0180] Compound 1 showed analgesic effect on day 14, 18 and 20 based on Von Frey test (table 20A and 20B).Table 20A: Von Frey of Study Groups (Mean ± SD) (g)Table 20B: Von Frey of Study Groups (Mean ± SD) (g)Note: Compared with the CCI+ vehicle (Gl), Statistical analysis was performed separately by one-way ANOVA test at each time point . **P<0.01 , *P<0.05.

[0181] As a control product, Pregabalin showed similar analgesic effect at 1, 3 and 24 hours post dose based on Von Frey and Dynamic Weight bearing measurement on day 14, 18 and 20. There was little or no analgesic effect from the topical administration of the placebo.Example 5: Patient Testing of Topical Formulations of Compound 1

[0182] This study provides exemplary data for topical formulations of Compound 1 tested on human patients. Patients administered 4 mL of placebo, 5% w / w or 10% w / w Compound 1 topical formulationsapplied once daily (QD), twice daily (BID) or thrice daily (TID) for 7 days in the knee area of patients with osteoarthritis of the knee, showed greater pain reduction, function and quality of life improvement compared with placebo treatment. Patients with neuropathic pain at baseline had greater magnitude of improvement from baseline than those without neuropathic pain.

[0183] As shown in FIG. 1, 5% or 10% Compound 1 topical application improved knee OA pain, stiffness, and physical function as assessed with validated Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC) evaluation tool in pooled BID and TID cohorts. The effect size of improvement over placebo was substantial compared with approved O A therapeutics.

[0184] As shown in FIG. 2, in Compound 1 treated patients, their daily walking pain showed steady increased improvement over time, with onset of effect at Day 5, in the pooled BID and TID cohorts.

[0185] As shown in FIG. 3, 5% or 10% Compound 1 topical BID and / or TID treatment greatly improved knee-OA interference on sleep quality with steady increased magnitude overtime and quick onset of effect since Day 2. The magnitude of improvement over placebo is substantial in terms of standard effect size.

[0186] The patient global impression of change (PGIC) was assessed by the end of the trial. More patients reported at least minimal improvement (minimal to marked improvement) in the Compound 1 5% or 10% BID or TID treatment than in the placebo, and less so in terms of percentage of patients got no changes or worsened as shown in FIG. 4.

[0187] The patients were assessed for the presence of neuropathic pain components with validated painDETECT tool at the baseline of trial. painDETECT score of <13 suggested the patient was unlikely to have neuropathic pain, and score of > 13 indicated the patient was likely to have neuropathic pain or the presence of neuropathic pain components. As shown in FIG. 5, 5% or 10% Compound 1 topical QD, BID or TID treatment resulted in greater magnitude of improvement in WOMAC pain, stiffness, physical function and total scores in patients with neuropathic pain components than no application of Compound 1.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method of reducing pain associated with a disease or disorder in a subject in need thereof; the method comprising topically administering a compound that is (3S)-3-((((l-(((S)-2-(6- methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid:

2. The method of claim 1, wherein the compound is (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen- 2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid:

3. The method of claim 1, wherein the compound is (S)-3-(((((R)-l-(((S)-2-(6-methoxynaphthalen- 2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid:

4. The method of any one of claims 1-3, wherein the compound penetrates into deep tissues following topical administration of the compound.

5. The method of any one of claims 1-3, wherein the compound penetrates into subcutaneous tissues following topical administration of the compound.

6. The method of any one of claims 1-3, wherein the compound penetrates into muscle layer following topical administration of the compound.

7. The method of any one of claims 1-3, wherein the compound penetrates into tendons following topical administration of the compound.

8. The method of any one of claims 1-3, wherein the compound penetrates into the nerves following topical administration of the compound.

9. The method of any one of claims 1-3, wherein the compound cleaves to release naproxen and pregabalin into deep tissues following topical administration of the compound.

10. The method of any one of claims 1-3, wherein the compound cleaves to release naproxen and pregabalin into subcutaneous tissues following topical administration of the compound.

11. The method of any one of claims 1-3, wherein the compound cleaves to release naproxen and pregabalin into muscle layer following topical administration of the compound.

12. The method of any one of claims 1-3, wherein the compound cleaves to release naproxen and pregabalin into tendons following topical administration of the compound.

13. The method of any one of claims 1-3, wherein the compound cleaves to release naproxen and pregabalin into nerves following topical administration of the compound.

14. The method of any one of claims 1-13, wherein the disease or disorder is migraine.

15. The method of claim 14, wherein the migraine is episodic migraine, chronic migraine, hemiplegic migraine, retinal migraine, menstrual migraine, migraine-associated vertigo, migraine with aura, or migraine without aura.

16. The method of claim 15, wherein the compound administration reduces muscle tension, muscle tenderness, and / or trigeminal nerve excitation, thereby reducing the pain associated with the migraine.

17. The method of any one of claims 1-13, wherein the pain is neck pain.

18. The method of claim 17, wherein the neck pain is caused by paraspinal muscle spasm.

19. The method of claim 17, wherein the neck pain is caused by the compression of spinal nerves.

20. The method of any one of claims 1-13, wherein the disease or disorder is cervical radiculopathy.

21. The method of any one of claims 1-13, wherein the pain is back pain.

22. The method of claim 21, wherein the back pain is caused by sciatica.

23. The method of any one of claims 1-13, wherein the disease or disorder is frozen shoulder.

24. The method of any one of claims 1-13, wherein the disease or disorder is rotator cuff tearing.

25. The method of claim 24, wherein the rotator cuff tearing involves the joint capsule.

26. The method of any one of claims 1-13, wherein the disease or disorder is deep tendonitis.

27. The method of any one of claims 1-13, wherein the disease or disorder is muscle tearing.

28. The method of any one of claims 1-13, wherein the disease or disorder is tennis elbow.

29. The method of any one of claims 1-13, wherein the disease or disorder is peripheral nerve entrapment.

30. The method of claim 29, wherein the peripheral nerve entrapment is cubital tunnel syndrome, carpal tunnel syndrome, Guyon’s cannel syndrome, or tarsal tunnel syndrome.

31. The method of any one of claims 1-13, wherein the disease or disorder is plantar fasciitis.

32. The method of any one of claims 1-13, wherein the disease or disorder is rheumatoid arthritis.

33. The method of claim 32, wherein the pain is joint pain.

34. The method of any one of claims 1-3, wherein the compound penetrates into the epidermis following topical administration of the compound.

35. The method of any one of claims 1-3, wherein the compound penetrates into the dermis following topical administration of the compound.

36. The method of any one of claims 1-3, wherein the compound cleaves to release naproxen and pregabalin into the epidermis following topical administration of the compound.

37. The method of any one of claims 1-3, wherein the compound cleaves to release naproxen and pregabalin into the dermis following topical administration of the compound.

38. The method of any one of claims 1-3 or 34-37, wherein the pain is neuralgia.

39. The method of any one of claims 1-3 or 34-37, wherein the neuralgia is trigeminal neuralgia.

40. The method of any one of claims 1-3 or 34-37, wherein the neuralgia is postherpetic neuralgia.

41. The method of any one of claims 1-3 or 34-37, wherein the neuralgia is diabetic peripheral neuralgia.

42. The method of any one of claims 1-3 or 34-37, wherein the disease or disorder is neuropathy.

43. The method of any one of claims 1-3 or 34-37, wherein the disease or disorder is small fiber neuropathy.

44. The method of any one of claims 1-3 or 34-37, wherein the pain is scar pain.

45. A method of preventing a migraine episode in a subject in need thereof; the method comprising topically administering a compound that is (3S)-3-((((l-(((S)-2-(6-methoxynaphthalen-2- yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl) -5 -methylhexanoic acid :

46. The method of claim 45, wherein the compound is (S)-3-(((((S)-l-(((S)-2-(6-methoxynaphthalen- 2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid:

47. The method of claim 46, wherein the compound is (S)-3-(((((R)-l-(((S)-2-(6- methoxynaphthalen-2-yl)propanoyl)oxy)ethoxy)carbonyl)amino)methyl)-5-methylhexanoic acid:

48. The method of any one of claims 45-47, wherein the compound penetrates into deep tissues following topical administration of the compound.

49. The method of any one of claims 45-47, wherein the compound penetrates into subcutaneous tissues following topical administration of the compound.

50. The method of any one of claims 45-47, wherein the compound penetrates into muscle layer following topical administration of the compound.

51. The method of any one of claims 45-47, wherein the compound penetrates into tendons following topical administration of the compound.

52. The method of any one of claims 45-47, wherein the compound penetrates into the nerves following topical administration of the compound.

53. The method of any one of claims 45-47, wherein the compound cleaves to release naproxen and pregabalin into deep tissues following topical administration of the compound.

54. The method of any one of claims 45-47, wherein the compound cleaves to release naproxen and pregabalin into subcutaneous tissues following topical administration of the compound.

55. The method of any one of claims 45-47, wherein the compound cleaves to release naproxen and pregabalin into muscle layer following topical administration of the compound.

56. The method of any one of claims 45-47, wherein the compound cleaves to release naproxen and pregabalin into tendons following topical administration of the compound.

57. The method of any one of claims 45-47, wherein the compound cleaves to release naproxen and pregabalin into nerves following topical administration of the compound.

58. The method of any one of claims 45-47, wherein the disease or disorder is migraine.

59. The method of claim 58, wherein the migraine is episodic migraine, chronic migraine, hemiplegic migraine, retinal migraine, menstrual migraine, migraine-associated vertigo, migraine with aura, or migraine without aura.

60. The method of claim 59, wherein the compound administration reduces muscle tension, muscle tenderness, and / or trigeminal nerve excitation, thereby preventing the migraine.

61. The method of any one of claims 1-60, wherein the compound is administered once a day.

62. The method of any one of claims 1-60, wherein the compound is administered not more than once a day.

63. The method of any one of claims 1-60, wherein the compound is administered twice a day.

64. The method of any one of claims 1-60, wherein the compound is administered not more than twice a day.

65. The method of any one of claims 1-60, wherein the compound is administered thrice a day.

66. The method of any one of claims 1-60, wherein the compound is administered not more than thrice a day.

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