{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T23:06:28Z","timestamp":1781219188079,"version":"3.54.1"},"reference-count":59,"publisher":"Elsevier BV","license":[{"start":{"date-parts":[[2018,8,1]],"date-time":"2018-08-01T00:00:00Z","timestamp":1533081600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/tdm\/userlicense\/1.0\/"},{"start":{"date-parts":[[2018,7,3]],"date-time":"2018-07-03T00:00:00Z","timestamp":1530576000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"name":"Mundipharma Research GmbH & Co.KG"}],"content-domain":{"domain":["elsevier.com","sciencedirect.com"],"crossmark-restriction":true},"short-container-title":["European Journal of Pharmacology"],"published-print":{"date-parts":[[2018,8]]},"DOI":"10.1016\/j.ejphar.2018.06.022","type":"journal-article","created":{"date-parts":[[2018,6,19]],"date-time":"2018-06-19T18:58:27Z","timestamp":1529434707000},"page":"370-378","update-policy":"https:\/\/doi.org\/10.1016\/elsevier_cm_policy","source":"Crossref","is-referenced-by-count":29,"special_numbering":"C","title":["Administration of a co-crystal of tramadol and celecoxib in a 1:1 molecular ratio produces synergistic antinociceptive effects in a postoperative pain model in rats"],"prefix":"10.1016","volume":"833","author":[{"given":"Manuel","family":"Merlos","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Enrique","family":"Portillo-Salido","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alex","family":"Brenchat","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bertrand","family":"Aubel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jordi","family":"Buxens","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angels","family":"Fisas","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xavier","family":"Codony","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luz","family":"Romero","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel","family":"Zamanillo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jos\u00e9 Miguel","family":"Vela","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"78","reference":[{"key":"10.1016\/j.ejphar.2018.06.022_bib1","doi-asserted-by":"crossref","first-page":"1182","DOI":"10.1007\/s00464-004-8254-x","article-title":"Preoperative use of selective COX-II inhibitors for pain management in laparoscopic Nissen fundoplication","volume":"19","author":"Alanoglu","year":"2005","journal-title":"Surg. Endosc."},{"key":"10.1016\/j.ejphar.2018.06.022_bib2","doi-asserted-by":"crossref","first-page":"1884","DOI":"10.1021\/acs.cgd.6b01848","article-title":"Co-crystal of Tramadol Hydrochloride-Celecoxib (ctc): a novel API-API Co-crystal for the treatment of pain","volume":"17","author":"Almansa","year":"2017","journal-title":"Cryst. Growth Des."},{"key":"10.1016\/j.ejphar.2018.06.022_bib3","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1016\/j.addr.2007.05.011","article-title":"Crystal engineering of active pharmaceutical ingredients to improve solubility and dissolution rates","volume":"59","author":"Blagden","year":"2007","journal-title":"Adv. Drug Deliv. Rev."},{"key":"10.1016\/j.ejphar.2018.06.022_bib4","first-page":"592","article-title":"Tramadol\/acetaminophen tablets in the treatment of postsurgical orthopedic pain","volume":"34","author":"Bourne","year":"2005","journal-title":"Am. J. Orthop."},{"key":"10.1016\/j.ejphar.2018.06.022_bib5","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/0304-3959(95)01441-1","article-title":"Characterization of a rat model of incisional pain","volume":"64","author":"Brennan","year":"1996","journal-title":"Pain"},{"key":"10.1016\/j.ejphar.2018.06.022_bib6","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1097\/ACO.0b013e328330373a","article-title":"Multimodal analgesia for controlling acute postoperative pain","volume":"22","author":"Buvanendran","year":"2009","journal-title":"Curr. Opin. Anaesthesiol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib7","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/0165-0270(94)90144-9","article-title":"Quantitative assessment of tactile allodynia in the rat paw","volume":"53","author":"Chaplan","year":"1994","journal-title":"J. Neurosci. Methods"},{"key":"10.1016\/j.ejphar.2018.06.022_bib8","doi-asserted-by":"crossref","first-page":"269","DOI":"10.2147\/CEOR.S61602","article-title":"Opioid-induced constipation in patients with chronic noncancer pain in the USA, Canada, Germany, and the UK: descriptive analysis of baseline patient-reported outcomes and retrospective chart review","volume":"6","author":"Coyne","year":"2014","journal-title":"Clin. Outcomes Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib9","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/S0014-2999(02)02920-5","article-title":"Enhancement of antinociception by co-administration of an opioid drug (morphine) and a preferential cyclooxygenase-2 inhibitor (rofecoxib) in rats","volume":"460","author":"D\u00e9ciga-Campos","year":"2003","journal-title":"Eur. J. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s40122-014-0026-2","article-title":"Oxycodone\/naloxone: role in chronic pain management, opioid-induced constipation, and abuse deterrence","volume":"3","author":"DePriest","year":"2014","journal-title":"Pain Ther."},{"key":"10.1016\/j.ejphar.2018.06.022_bib11","doi-asserted-by":"crossref","first-page":"711","DOI":"10.2165\/11205830-000000000-00000","article-title":"Tramadol\/paracetamol fixed-dose combination: a review of its use in the management of moderate to severe pain","volume":"30","author":"Dhillon","year":"2010","journal-title":"Clin. Drug. Investig."},{"key":"10.1016\/j.ejphar.2018.06.022_bib12","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/S0165-0270(97)00097-6","article-title":"Characterization of variables defining hindpaw withdrawal latency evoked by radiant thermal stimuli","volume":"76","author":"Dirig","year":"1997","journal-title":"J. Neurosci. Methods"},{"key":"10.1016\/j.ejphar.2018.06.022_bib13","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1146\/annurev.pa.20.040180.002301","article-title":"Efficient analysis of experimental observations","volume":"20","author":"Dixon","year":"1980","journal-title":"Annu. Rev. Pharmacol. Toxicol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib14","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/S0885-3924(01)00404-3","article-title":"Combination analgesic efficacy: individual patient data meta-analysis of single-dose oral tramadol plus acetaminophen in acute postoperative pain","volume":"23","author":"Edwards","year":"2002","journal-title":"J. Pain. Symptom Manag."},{"key":"10.1016\/j.ejphar.2018.06.022_bib15","doi-asserted-by":"crossref","first-page":"846","DOI":"10.1111\/j.1476-5381.1992.tb14423.x","article-title":"Modulation by opioids and by afferent sensory neurones of prostanoid protection of the rat gastric mucosa","volume":"106","author":"Esplugues","year":"1992","journal-title":"Br. J. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib16","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1016\/S0149-2918(02)80010-8","article-title":"A double-blind, single-dose comparison of the analgesic efficacy of tramadol\/acetaminophen combination tablets, hydrocodone\/acetaminophen combination tablets, and placebo after oral surgery","volume":"24","author":"Fricke","year":"2002","journal-title":"Clin. Ther."},{"key":"10.1016\/j.ejphar.2018.06.022_bib17","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.pain.2004.01.004","article-title":"A double-blind placebo-controlled comparison of tramadol\/acetaminophen and tramadol in patients with postoperative dental pain","volume":"109","author":"Fricke","year":"2004","journal-title":"Pain"},{"key":"10.1016\/j.ejphar.2018.06.022_bib18","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1016\/j.pbb.2007.05.007","article-title":"Co-administration of rofecoxib and tramadol results in additive or sub-additive interaction during arthritic nociception in rat","volume":"87","author":"Garc\u00eda-Hern\u00e1ndez","year":"2007","journal-title":"Pharmacol. Biochem. Behav."},{"key":"10.1016\/j.ejphar.2018.06.022_bib19","doi-asserted-by":"crossref","first-page":"879","DOI":"10.2165\/00003088-200443130-00004","article-title":"Clinical pharmacology of tramadol","volume":"43","author":"Grond","year":"2004","journal-title":"Clin. Pharmacokinet."},{"key":"10.1016\/j.ejphar.2018.06.022_bib20","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/0304-3959(88)90026-7","article-title":"A new and sensitive method for measuring thermal nociception in cutaneous hyperalgesia","volume":"32","author":"Hargreaves","year":"1988","journal-title":"Pain"},{"key":"10.1016\/j.ejphar.2018.06.022_bib21","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1159\/000090321","article-title":"NSAID-associated dyspepsia and ulcers: a prospective cohort study in primary care","volume":"24","author":"Hollenz","year":"2006","journal-title":"Dig. Dis."},{"key":"10.1016\/j.ejphar.2018.06.022_bib22","first-page":"1039","article-title":"Preoperative oral rofecoxib reduces postoperative pain and tramadol consumption in patients after abdominal hysterectomy","volume":"98","author":"Karamanho\u011flu","year":"2004","journal-title":"Anesth. Analg."},{"key":"10.1016\/j.ejphar.2018.06.022_bib23","doi-asserted-by":"crossref","first-page":"e1000412","DOI":"10.1371\/journal.pbio.1000412","article-title":"Improving bioscience research reporting: the ARRIVE guidelines for reporting animal research","volume":"8","author":"Kilkenny","year":"2010","journal-title":"PLoS Biol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib24","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1002\/ddr.430330105","article-title":"Surface of synergistic interaction between dipyrone and morphine in the PIFIR model","volume":"33","author":"L\u00f3pez-Mu\u00f1oz","year":"1994","journal-title":"Drug Dev. Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib25","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1002\/ddr.430290408","article-title":"Analgesic effects of combinations contain opioid drugs with either aspirin or acetaminophen in the rat","volume":"29","author":"L\u00f3pez-Mu\u00f1oz","year":"1993","journal-title":"Drug Dev. Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib26","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.ejphar.2003.11.005","article-title":"Analysis of the analgesic interactions between ketorolac and tramadol during arthritis nociception in rat","volume":"484","author":"L\u00f3pez-Mu\u00f1oz","year":"2004","journal-title":"Eur. J. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib27","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.pbb.2008.07.007","article-title":"The antinociceptive efficacy of morphine, metamizol, or their combination in an experimental rat model with different levels of inflammatory pain","volume":"91","author":"L\u00f3pez-Mu\u00f1oz","year":"2008","journal-title":"Pharmacol. Biochem. Behav."},{"issue":"32","key":"10.1016\/j.ejphar.2018.06.022_bib28","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1002\/ddr.430320108","article-title":"Analgesic interactions produced by dypirone and either morphine or d-propoxyphene in the pain induced functional impairment model in rat","volume":"1994","author":"L\u00f3pez-Mu\u00f1oz","year":"1994","journal-title":"Drug Dev. Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib29","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.phrs.2007.04.003","article-title":"Tramadol is more effective than morphine and amitriptyline against ischaemic pain but not thermal pain in rats","volume":"56","author":"Loram","year":"2007","journal-title":"Pharmacol. Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib30","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.jpain.2010.07.006","article-title":"Combination drug therapy for chronic pain: a call for more clinical studies","volume":"12","author":"Mao","year":"2011","journal-title":"J. Pain"},{"key":"10.1016\/j.ejphar.2018.06.022_bib31","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1097\/00000542-199405000-00018","article-title":"Ketorolac potentiates morphine antinociception during visceral nociception in the rat","volume":"80","author":"Maves","year":"1994","journal-title":"Anesthesiology"},{"key":"10.1016\/j.ejphar.2018.06.022_bib32","doi-asserted-by":"crossref","first-page":"2457","DOI":"10.2165\/11208240-000000000-00000","article-title":"Celecoxib: a review of its use for symptomatic relief in the treatment of osteoarthritis, rheumatoid arthritis and ankylosing spondylitis","volume":"71","author":"McCormack","year":"2011","journal-title":"Drugs"},{"key":"10.1016\/j.ejphar.2018.06.022_bib33","doi-asserted-by":"crossref","first-page":"861","DOI":"10.14219\/jada.archive.2002.0300","article-title":"The efficacy of combination analgesic therapy in relieving dental pain","volume":"133","author":"Mehlisch","year":"2002","journal-title":"J. Am. Dent. Assoc."},{"key":"10.1016\/j.ejphar.2018.06.022_bib34","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.pbb.2012.07.011","article-title":"Antinociceptive effects of tramadol in co-administration with metamizol after single and repeated administration in rats","volume":"103","author":"Moreno-Rocha","year":"2012","journal-title":"Pharmacol. Biochem. Behav."},{"key":"10.1016\/j.ejphar.2018.06.022_bib35","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.pbb.2007.07.003","article-title":"Evaluation of the interaction between acemetacin and opioids on the Hargreaves model of thermal hyperalgesia","volume":"88","author":"Ortiz","year":"2007","journal-title":"Pharmacol. Biochem. Behav."},{"key":"10.1016\/j.ejphar.2018.06.022_bib36","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/S0304-3959(97)00128-0","article-title":"Ketorolac potentiates morphine in postoperative patient-controlled analgesia","volume":"73","author":"Picard","year":"1997","journal-title":"Pain"},{"key":"10.1016\/j.ejphar.2018.06.022_bib37","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1080\/08897077.2012.735216","article-title":"Topical review on the abuse and misuse potential of tramadol and tilidine in Germany","volume":"34","author":"Radbruch","year":"2013","journal-title":"Subst. Abus."},{"key":"10.1016\/j.ejphar.2018.06.022_bib38","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1111\/j.1365-2710.2008.00897.x","article-title":"Basic pharmacology relevant to drug abuse assessment: tramadol as example","volume":"33","author":"Raffa","year":"2008","journal-title":"J. Clin. Pharm. Ther."},{"key":"10.1016\/j.ejphar.2018.06.022_bib39","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1016\/j.jpain.2009.12.010","article-title":"The determination and application of fixed-dose analgesic combinations for treating multimodal pain","volume":"11","author":"Raffa","year":"2010","journal-title":"J. Pain"},{"key":"10.1016\/j.ejphar.2018.06.022_bib40","doi-asserted-by":"crossref","first-page":"103","DOI":"10.2147\/JPR.S16760","article-title":"Tramadol\/paracetamol combination tablet for postoperative pain following ambulatory hand surgery: a double-blind, double dummy, randomized, parallel-group trial","volume":"4","author":"Rawal","year":"2011","journal-title":"J. Pain Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib41","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1002\/ddr.430360304","article-title":"Synergistic antinociceptive interaction between aspirin and tramadol, the atypical opioid analgesic, in the rat","volume":"36","author":"Salazar","year":"1995","journal-title":"Drug Dev. Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib42","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/S0014-2999(98)00496-8","article-title":"Acetylsalicylic acid potentiates the antinociceptive effect of morphine in the rat: involvement of the central serotonergic system","volume":"355","author":"Sandrini","year":"1998","journal-title":"Eur. J. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib43","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1007\/s000110050434","article-title":"The potentiation of analgesic activity of acetaminophen plus morphine involves the serotonergic system in rat brain","volume":"48","author":"Sandrini","year":"1999","journal-title":"Inflamm. Res."},{"key":"10.1016\/j.ejphar.2018.06.022_bib44","doi-asserted-by":"crossref","first-page":"1859","DOI":"10.1111\/j.1526-4637.2010.00983.x","article-title":"Causes and consequences of inadequate management of acute pain","volume":"11","author":"Sinatra","year":"2010","journal-title":"Pain Med."},{"key":"10.1016\/j.ejphar.2018.06.022_bib45","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/j.amjsurg.2003.12.038","article-title":"Combination tramadol plus acetaminophen for postsurgical pain","volume":"187","author":"Smith","year":"2004","journal-title":"Am. J. Surg."},{"key":"10.1016\/j.ejphar.2018.06.022_bib46","doi-asserted-by":"crossref","first-page":"865","DOI":"10.1016\/S0022-3565(24)29450-7","article-title":"Drug synergism: its detection and applications","volume":"298","author":"Tallarida","year":"2001","journal-title":"J. Pharmacol. Exp. Ther."},{"key":"10.1016\/j.ejphar.2018.06.022_bib47","first-page":"23","article-title":"Testing for synergism over a range of fixed ratio drug combinations: replacing the isobologram","volume":"58","author":"Tallarida","year":"1996","journal-title":"Life Sci."},{"key":"10.1016\/j.ejphar.2018.06.022_bib48","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/S0014-2999(98)00298-2","article-title":"Metamizol potentiates morphine effects on visceral pain and evoked c-fos immunoreactivity in spinal cord","volume":"351","author":"Taylor","year":"1998","journal-title":"Eur. J. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib49","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1016\/j.drudis.2016.02.001","article-title":"Multidrug cocrystals: towards the development of effective therapeutic hybrids","volume":"21","author":"Thipparaboina","year":"2016","journal-title":"Drug Discov. Today"},{"key":"10.1016\/j.ejphar.2018.06.022_bib50","doi-asserted-by":"crossref","first-page":"460","DOI":"10.1016\/j.jpain.2006.12.005","article-title":"PEMI study group. Pain in the emergency department: results of the pain and emergency medicine initiative (PEMI) multicenter study","volume":"8","author":"Todd","year":"2007","journal-title":"J. Pain"},{"key":"10.1016\/j.ejphar.2018.06.022_bib51","doi-asserted-by":"crossref","first-page":"2226","DOI":"10.1016\/S0140-6736(11)60402-9","article-title":"Treatment of chronic non-cancer pain","volume":"377","author":"Turk","year":"2011","journal-title":"Lancet"},{"key":"10.1016\/j.ejphar.2018.06.022_bib52","doi-asserted-by":"crossref","first-page":"1479","DOI":"10.1038\/sj.bjp.0701818","article-title":"Enhancement of opioid inhibition of GABAergic synaptic transmission by cyclooxygenase inhibitors in rat periaqueductal grey neurons","volume":"123","author":"Vaughan","year":"1998","journal-title":"Br. J. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib53","unstructured":"Videla, S., L\u00f3pez-Cedr\u00fan, J., Burgue\u00f1o, M., Ju\u00e1rez, I., Aboul-Hosn, S., Mart\u00edn-Granizo, R., Grau, J., Puche, M., Gil-Diez, J., Hueto, J., Vaqu\u00e9, A., Sust, M., Plata-Salam\u00e1n, C., Monner, A., 2016. Co-crystal of tramadol-celecoxib: efficacy and safety results from a dose-finding, randomised, double-blind, multicentre, phase II clinical trial in patients with moderate to severe acute pain due to an oral surgical procedure. In: Proceedings of IASP 16th World Congress of Pain, Yokohama, Toyko, September 26\u201330, PW0293."},{"key":"10.1016\/j.ejphar.2018.06.022_bib54","doi-asserted-by":"crossref","first-page":"2718","DOI":"10.1111\/bcp.13395","article-title":"Single-dose pharmacokinetics of co-crystal of tramadol-celecoxib: results of a four-way randomized open-label phase I clinical trial in healthy subjects","volume":"83","author":"Videla","year":"2017","journal-title":"Br. J. Clin. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib55","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1111\/bcp.13428","article-title":"Pharmacokinetics of multiple doses of co-crystal of tramadol-celecoxib: findings from a four-way randomized open-label phase I clinical trial","volume":"84","author":"Videla","year":"2018","journal-title":"Br. J. Clin. Pharmacol."},{"key":"10.1016\/j.ejphar.2018.06.022_bib56","doi-asserted-by":"crossref","first-page":"995","DOI":"10.1213\/00000539-199910000-00032","article-title":"Patient-controlled analgesia with morphine plus lysine acetyl salicylate","volume":"89","author":"Wei-wu","year":"1999","journal-title":"Anesth. Analg."},{"key":"10.1016\/j.ejphar.2018.06.022_bib57","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/S0009-9236(99)70123-2","article-title":"Analgesic efficacy of a combination of hydrocodone with ibuprofen in postoperative pain","volume":"65","author":"Wideman","year":"1999","journal-title":"Clin. Pharmacol. Ther."},{"key":"10.1016\/j.ejphar.2018.06.022_bib58","doi-asserted-by":"crossref","first-page":"359","DOI":"10.4103\/0250-474X.57283","article-title":"Co-crystals: a novel approach to modify physicochemical properties of active pharmaceutical ingredients","volume":"71","author":"Yadav","year":"2009","journal-title":"Indian J. Pharm. Sci."},{"key":"10.1016\/j.ejphar.2018.06.022_bib59","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/0304-3959(83)90201-4","article-title":"Ethical guidelines for investigations of experimental pain in conscious animals","volume":"16","author":"Zimmermann","year":"1983","journal-title":"Pain"}],"container-title":["European Journal of Pharmacology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0014299918303534?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0014299918303534?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2025,7,5]],"date-time":"2025-07-05T06:17:01Z","timestamp":1751696221000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/S0014299918303534"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,8]]},"references-count":59,"alternative-id":["S0014299918303534"],"URL":"https:\/\/doi.org\/10.1016\/j.ejphar.2018.06.022","relation":{},"ISSN":["0014-2999"],"issn-type":[{"value":"0014-2999","type":"print"}],"subject":[],"published":{"date-parts":[[2018,8]]},"assertion":[{"value":"Elsevier","name":"publisher","label":"This article is maintained by"},{"value":"Administration of a co-crystal of tramadol and celecoxib in a 1:1 molecular ratio produces synergistic antinociceptive effects in a postoperative pain model in rats","name":"articletitle","label":"Article Title"},{"value":"European Journal of Pharmacology","name":"journaltitle","label":"Journal Title"},{"value":"https:\/\/doi.org\/10.1016\/j.ejphar.2018.06.022","name":"articlelink","label":"CrossRef DOI link to publisher maintained version"},{"value":"article","name":"content_type","label":"Content Type"},{"value":"\u00a9 2018 The Authors. Published by Elsevier B.V.","name":"copyright","label":"Copyright"}]}}