UR-144 N-5-Hydroxypentyl is a potent synthetic cannabinoid designed by Abbott Laboratories as a CB2 selective agonist for pain management. UR-144 N-5-Hydroxypentyl is a metabolite of another CB2-selective cannabinoid UR-144. Pre-clinical studies of nociceptive and neuropathic pain have shown that CB2-selective ligands are analgesics without causing the adverse side effects linked with CB1 receptor activation. However, nor UR-144 nor UR-144 N-5-Hydroxypentyl has no therapeutic application.

P-88-8991 (Hydroxy Iloperidone, 4-[3-[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl] propoxy]- 3-methoxy-methylbenzenemethanol) is the major active metabolite of Iloperidone an atypical antipsychotic that used for the acute treatment of schizophrenia in adults. Metabolic reduction of Iloperidone carbonyl group leads to P-88-8991 in rats, dogs, and humans. The receptor affinity profile of P-88-8991 is comparable to that of iloperidone: this metabolite binds to the serotonin 5-HT2A receptors, adrenergic alpha1 and alpha2C receptors, and D2A receptors and with lower affinity to other monoamine (dopamine, serotonin, and histamine H1 ) receptors. The comparable receptor binding profile of P-88-8991 indicates that it is likely to contribute to the clinical profile of iloperidone. Preclinical experiments, such as the mouse apomorphine climbing test, the rat self-stimulation, and the pole climb avoidance task, indicate antipsychotic activity of P88-8991 and confirm that this metabolite crosses the blood–brain barrier

(S)-ketorolac is the enantiomer of ketorolac, a nonsteroidal anti-inflammatory drug. (S)-ketorolac exhibited potent cyclooxygenase (COX1 and COX2) enzyme inhibition. (S)-ketorolac is considered to be active enantiomer of racemic ketorolac.

AH-7921 (3,4-Dichloro-N-([1-(dimethylamino)cyclohexyl] methyl)benzamide) is an N-substituted cyclohexylmethylbenzamide classified as an opioid analgesic with high addictive liability. The compound acts as an agonist of μ-opioid receptors, although at high doses it can also stimulate κ-opioid receptors. In animal studies, AH-7921 produced typical morphine-like actions, i.e., antinociception, respiratory depression, sedation, miosis, inhibition of gut propulsion, and lowered body temperature, with a potency almost equipotent to that of morphine. There is limited information available on the routes of administration and the doses of AH-7921 used. The compound is taken orally, nasally, by smoking, and, less commonly, by intravenous injection. Minimal oral effective doses for complete pain suppression by AH 7921 are 1.25 and 13.8 mg/kg for canine and rhesus monkey, respectively.

Racemic phenibut (beta-phenyl-gamma-aminobutyric acid or 4-amino-3-phenylbutyric acid) is a neuropsychotropic drug that was discovered and introduced into clinical practice in Russia in the 1960s. In pharmacological tests of locomotor activity, antidepressant and pain effects, S-phenibut was inactive. In contrast, R-phenibut turned out to be two times more potent than racemic phenibut in most of the tests. Racemic phenibut and R-phenibut demonstrated an affinity for GABAB receptors, in contrast, S-phenibut was not able to bind receptors. Pharmacological activity of racemic phenibut relies on R-phenibut and this correlates to the binding affinity of enantiomers of phenibut to the GABAB receptor. Both S- and R-phenibut bind to the α2-δ subunit of voltage-dependent calcium channels and exert gabapentin-like anti-nociceptive effects. In addition S-isomer was found to be a substrate of gamma-aminobutyric acid aminotransferase, however, the R-isomer is a competitive inhibitor.

A-967079 is a potent, selective, and orally bioavailable inhibitor of the TRPA1 channel, developed by developed by Abbott Laboratories for treatment pain disorder. A-967079 potently blocks human and rat TRPA1 channels. A-967079 is 1000-fold selective over other TRP channels and is 150-fold selective over 75 other ion channels, enzymes, and G-protein-coupled receptors. Oral dosing of A-967079 produces robust drug exposure in rodents and exhibits analgesic efficacy in allyl isothiocyanate-induced nocifensive response and osteoarthritic pain in rats. A-967079 attenuates cold allodynia produced by nerve injury but does not alter noxious cold sensation in naive animals, suggesting distinct roles of TRPA1 in physiological and pathological states. Unlike TRPV1 antagonists, A-967079 does not alter body temperature. It also does not produce locomotor or cardiovascular side effects.

A-987306 is a new histamine H(4) antagonist. A-987306 is potent in H(4) receptor binding assays (rat H(4), K(i) = 3.4 nM, human H(4) K(i) = 5.8 nM) and demonstrated potent functional antagonism in vitro at human, rat, and mouse H(4) receptors in cell-based FLIPR assays. A-987306 also demonstrated H(4) antagonism in vivo in mice, blocking H(4)-agonist induced scratch responses, and showed anti-inflammatory activity in mice in a peritonitis model. Most interesting was the high potency and efficacy of this compound in blocking pain responses, where it showed an ED(50) of 42 umol/kg (ip) in a rat post-carrageenan thermal hyperalgesia model of inflammatory pain. A-987306 inhibited the scratching response (IC50 = 0.4 umoles/kg, i.p.) with (85%) inhibition seen at 30 umoles/kg, i.p. A-987306 is a potent and selective H4R antagonist with robust antipruritic activity and is a useful tool for further exploration of the role of H4R receptors in vivo.

A-943931 is a potent and selective H4R antagonist with high affinity at both human (Kis = 4.6 nM) and rat (Kis = 3.8 nM) receptors. A-943931 competitively and potently antagonizes rat H4R agonist-mediated responses in [35S]GTPγS binding assays (Kbs = 28 nM) and intracellular calcium mobilization at rat and human receptors (Kbs from 5-10 nM). When tested in vivo in a mouse model of clobenpropit (10 nM, i.d.) induced scratching, A-943931 inhibited the scratching response (IC50 = 26 umoles/kg, i.p.) with significant inhibition (69%) at the highest tested dose (30 umoles/kg, i.p.). A-943931 is a potent and selective H4R antagonist with robust antipruritic activity and is a useful tool for further exploration of the role of H4R receptors in vivo.

PHA-543613 was discovered by Pfizer and has been under development primarily as a potential treatment of schizophrenia. PHA-543613 acts as an agonist to the Neuronal acetylcholine receptor protein alpha-7 subunit. A single human trial was conducted in healthy human volunteers, but the compound has been studied extensively in rat models for schizophrenia as well as Parkinson's disease and Alzheimer's disease.

GW-9508 is a small-molecule agonist of the fatty acid receptors GPR40 and GPR120. GW-9508 exerts wide-range activity in animal models: anti-depressant, anti-inflammatory, anti-diabetic and analgetic actions.