Comprehensive overview of analytical and bioanalytical methodologies for the opioid analgesics - Tramadol and combinations

Synthetic opioids like Tramadol are used to treat mild to moderate pain. Its ability to relieve pain is about a tenth that of morphine. Furthermore, Tramadol shares similar effects on serotonin and norepinephrine to several antidepressants known as serotonin-norepinephrine reuptake inhibitors (SNRIs), such as venlafaxine and duloxetine. The present review paper discusses the recent developments in analytical methods for identifying drugs in pharmaceutical preparations and toxicological materials, such as blood, saliva, urine, and hair. In recent years, a wide variety of analytical instruments, including capillary electrophoresis, NMR, UV-visible spectroscopy, HPTLC, HPLC, LC-MS, GC, GC-MS, and electrochemical sensors, have been used for drug identification in pharmaceutical preparations and toxicological samples. The primary quantification techniques currently employed for its quantification in various matrices are highlighted in this research.

Simultaneous Quantification of Opioids in Blood and Urine by Gas Chromatography-Mass Spectrometer with Modified Dispersive Solid-Phase Extraction Technique

Common methodologies such as liquid-liquid extraction and solid-phase extraction are applied for the extraction of opioids from biological specimens i.e., blood and urine. Techniques including LC-MS/LC-MSMS, GC-MS, etc. are used for qualitative or quantitative determination of opioids. The goal of the present work is to design a green, economic, rugged, and simple extraction technique for famous opioids in human blood and urine and their simultaneous quantification by GC-MS equipped with an inert plus electron impact (EI) ionization source at SIM mode to produce reproducible and efficient results. Morphine, codeine, 6-acetylmorphine, nalbuphine, tramadol and dextromethorphan were selected as target opioids. Anhydrous Epsom salt was applied for dSPE of opioids from blood and urine into acetonitrile extraction solvent with the addition of sodium phosphate buffer (pH 6) and n-hexane was added to remove non-polar interfering species from samples. BSTFA was used as a derivatizing agent for GC-MS. Following method validation, the LOD/LLOQ and ULOQ were determined for morphine, codeine, nal-buphine, tramadol, and dextromethorphan at 10 ng/mL and 1500 ng/mL, respectively, while the LOD/LLOQ and ULOQ were determined for 6-acetylmorphine at 5 ng/mL and 150 ng/mL, respectively. This method was applied to real blood and urine samples of opioid abusers and the results were found to be reproducible with true quantification.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Development and validation of a new GC-MS method for the detection of tramadol, O-desmethyltramadol, 6-acetylmorphine and morphine in blood, brain, liver and kidney of Wistar rats treated with the combination of heroin and tramadol

Heroin is one of the most dangerous abused drugs in the world. Tramadol is an additive recently found at high concentration levels in street heroin seizures in Egypt. This substance could affect the usual analytical method for the detection of heroin and metabolites, as well as the pharmacokinetic and disposition of single analytes. One shortfall regarding this issue is present in the literature. This study describes a validated, simple, sensitive and selective method to determine tramadol, O-desmethyltramadol, 6-acetylmorphine and free morphine in the blood, brain, liver and kidney of Wistar rats, intraperitoneally treated with a combination of heroin and tramadol (10 and 70 mg/kg, respectively) using liquid-liquid extraction and gas chromatography-mass spectrometry detection. The calibration curves of tramadol, O-desmethyltramadol and 6-acetylmorphine in blood were linear in the concentration range from 25-5,000 ng/mL and morphine was found in the concentration range 50-5,000 ng/mL. The analytes were detected in all tested matrices, except 6-acetylmorphine, which was not detected in liver. The highest concentrations of tramadol and O-desmethyltramadol were observed in kidney (22,9381 and 28,498 ng/g), while 6-acetylmorphine and morphine were found at the highest levels in brain (3,280 and 3,899 ng/g, respectively). The present method is simple, rapid and sensitive and can be used to study the pharmacokinetics, disposition and interaction of these drugs in several animal models.