An integrated microfluidic device for solid-phase extraction and spectrophotometric detection of opium alkaloids in urine samples.

A novel lab-on-chip integrated microfluidic device for solid-phase extraction (SPE) and spectrophotometric detection of morphine (MOR), codeine (COD), and papaverine (PAP) was developed. The extracted analytes were analyzed with a miniature UV-Vis spectrophotometer. The SPE adsorptive phase composed of polyurethane/polyaniline (PU/PANI) nanofibers was fabricated by electrospinning and in situ oxidative polymerization techniques. The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The main factors of extraction such as desorption conditions, pH, salt effect, and extraction time were investigated. The partial least square (PLS) regression was applied to improve the quantification of analytes. The linear dynamic ranges (LDRs) for MOR, COD, and PAP were 4-240, 4-210, and 1-150 ng mL-1, respectively. Finally, the proposed method was successfully applied for the determination of MOR, COD, and PAP in human urine samples and the extraction recoveries were obtained in the range of 66.7-85.0% with RSDs < 8.3%.

Using Papaverine and Its Metabolites, 6-Desmethyl Papaverine and 4',6-Didesmethyl Papaverine as Biomarkers to Improve the Detection Time of Heroin Use.

Opioid usage in the USA has increased over the past decade, with prescriptions increasing from 76 million in 1991 to 207 million in 2013. New regulations have curbed the number of prescriptions, leading to an increase in heroin use. Heroin-related overdoses have quadrupled between 2000 and 2015. The traditional urinary biomarkers for indicating heroin use are a combination of morphine and 6-acetyl morphine (6-AM). Morphine is detectable in urine for several days. 6-AM is detected in urine for 2-8 hours. Papaverine has been proposed as an alternative heroin biomarker. It has been reported to have a 1-2 day detection window. Papaverine metabolites have been reported to have up to a 3-day detection window. Presented is a method for the detection of papaverine and its metabolites, 6-desmethyl papaverine (6-DMP) and 4', 6-didesmethyl papaverine (4,6-DDMP), in urine using a modified Waters® MCX™ microelution method. An ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS-MS), with a Waters' BEH C18 column, and 20 mM ammonium formate water: 20 mM ammonium formate methanol mobile phase was employed. Calibration curves were linear from 0.1 to 50 ng/mL. No interferences were observed from the analysis of multicomponent therapeutic drug or drugs of abuse control materials; intra- and inter-run precision tests were acceptable. A total of 428 genuine urine specimens where heroin use was suspected were analyzed. These included 101 6-AM and 179 morphine only positive samples as well as 6 morphine-negative samples where papaverine and/or metabolites were detected. The determined concentrations in these samples for papaverine, 6-DMP and 4,6-DDMP ranged from 0.10 to 994, 0.10 to 462 and 0.12 to 218 ng/mL, respectively. The method was rugged and robust for the analysis of papaverine and metabolites, 6-DMP and 4,6-DDMP. The use papaverine and metabolites, 6-DMP and 4,6-DDMP has the potential to increase the detection window of heroin use.

Coupling of micro-solid-phase extraction and internal extractive electrospray ionization mass spectrometry for ultra-sensitive detection of 1-hydroxypyrene and papaverine in human urine samples.

Quantification of ultra-trace analytes in complex biological samples using micro-solid-phase extraction followed by direct detection with internal extractive electrospray ionization mass spectrometry (µSPE-iEESI-MS) was demonstrated. 1-Hydroxypyrene (1-OHP) and papaverine at attomole levels in human raw urine samples were analyzed under negative and positive ion detection mode, respectively. The µSPE was simply prepared by packing a disposable syringe filter with octadecyl carbon chain (C18)-bonded micro silica particles, which were then treated as the "bulk sample" after the analytes were efficiently enriched by the C18 particles. Under the optimized experimental conditions, the analytes were readily eluted by isopropanol/water (80/20, V/V) at a high voltage of ± 4.0 kV, producing analyte ions under ambient conditions. The limit of detection (LOD) was 0.02 pg/L (9.2 amol) for 1-hydroxypyrene and 0.02 pg/L (5.9 amol) for papaverine. The acceptable linearity (R2 > 0.99), signal stability (RSD ≤ 10.7%), spike recoveries (91-95%), and comparable results for real urine samples were also achieved, opening up possibilities for quantitative analysis of trace compounds (at attomole levels) in complex bio-samples. Graphical abstract.

Direct Analysis of Free Aqueous and Organic Operational Solutions as a Tool for Understanding Fundamental Principles of Electromembrane Extraction.

Aqueous and organic phases in microelectromembrane extraction (µ-EME) were formed as adjacent plugs of free immiscible solutions in narrow-bore polymeric tubing, and each single phase was recovered and analyzed after µ-EME. A three-phase µ-EME setup was employed for investigation of time-dependent distribution of model basic drugs among aqueous and organic phases. Exact concentrations of nortriptyline and papaverine in donor solution, acceptor solution, and free liquid membrane (FLM) were determined by capillary electrophoresis with ultraviolet detection (CE-UV). At typical µ-EME conditions (acceptor, 1 µL of 25 mM HCl; FLM, 1 µL of 4-nitrocumene; donor, 1 µL of basic drugs in 10 mM HCl; and extraction potential, 250 V), experimentally determined distribution of the drugs confirmed the kinetic model for electrically mediated transfer of charged analytes. Rapid depletion of the drugs from donor solution (0-180 s) and rapid saturation of FLM with the drugs (15-60 s) were followed by gradual transfer of the drugs across FLM and gradual liberation into acceptor solution (30-240 s). Exhaustive transfer of the drugs from donor to acceptor solution was obtained in 15 min. A good correlation between the analytes' distribution and µ-EME electric currents was observed; the currents increased during drugs' transfer across FLM, were concentration dependent, and demonstrated transfer of the drugs across FLM in their ionized forms. Proper understanding of the fundamental principles of µ-EME transfer enabled further fine-tuning of the µ-EME process. Transfer of the drugs across FLM was controlled by optimizing the composition and pH of acceptor solution, and quantitative fractionation of nortriptyline into aqueous acceptor (96%) and of papaverine into organic FLM (95%) was achieved based on their different pKa values. µ-EME fractionation of the two drugs was compatible with raw human urine and excellent repeatability (RSD ≤ 3.9%), linearity (r2 ≥ 0.9989), and limits of detection (≤ 0.15 µg/mL) were achieved for µ-EME-CE-UV of the drugs in standard solutions and urine samples.

Embutramide, a Component of Tanax(®) (T-61) as a New Drug of Abuse?

Tanax(®) (T-61) is a euthanasia solution commonly used in veterinary medicine in Europe. It consists of three active components: embutramide, mebezonium iodide, and tetracaine hydrochloride. Human consumption of Tanax(®) (T-61) is usually associated with suicide attempts. In our 15-year-long practice, embutramide was detected only three times but within a short period. First, it was found in the urine of a 42-year-old veterinarian, and the other two observations were made in a 16-year-old young man. Urine samples were analyzed using Shimadzu Prominence TOX.I.S.II. HPLC-DAD system with online SPE extraction system. Both of the two patients denied any intention to die. These cases show that this veterinary drug may also be considered as potential drugs of abuse.

Cathodic adsorptive stripping voltammetry of drotaverine hydrochloride and its determination in tablets and human urine by differential pulse voltammetry.

The stripping voltammetric behaviour of drotaverine hydrochloride (DvCl) was studied using a hanging mercury drop electrode (HMDE). The adsorptive stripping response has been evaluated with respect to pH, accumulation time, accumulation potential, scan rate and other variables. Differential pulse DP mode; over the potential range -400 to -1200 mV, is used in the presence of 0.04 M Britton-Robinson buffer pH 2. Cyclic voltammetric study indicates that the reduction process is irreversible and controlled by adsorption. The response of DP technique is linear over the concentration range 21.70-257.34 ng/ml. Limit of detection and limit of quantification were 3.15 and 10.50 ng/ml, respectively. The proposed method was successfully applied for the determination of the drug in commercial tablets and spiked human urine samples.

The significance of putative urinary markers of illicit heroin use after consumption of poppy seed products.

After consumption of poppy seeds various substances were detected in urine or blood samples using an immunoassay and a sophisticated liquid chromatographic-tandem mass spectrometric procedure. These compounds are widely considered to be putative markers of heroin (HER) abuse whereas acetylcodeine was regarded as a marker for illicit preparations ("street HER"). Besides positive urinary opiate immunoassay results during a 48 hours monitoring period, peak concentrations of morphine (MOR), codeine and their glucuronides appeared 4 to 8 hours after ingestion of poppy seeds, and concentrations of total MOR higher than 10 microg/mL were observed. Also, in serum samples taken up to 6 hours after consumption, MOR glucuronides were found. Free MOR was only detected in traces (1 to 3 ng/mL) within 2 hours of consumption. In addition, 3 of 6 onsite opiate sweat tests revealed positive results 6.5 hours after ingestion. Furthermore, it was demonstrated that neither noscapine (NOS) nor papaverine (PAP) was detectable in urine or blood samples after the consumption of poppy seeds containing up to 94 microg NOS and up to 3.3 mug PAP. NOS and PAP were rapidly metabolized, whereas desmethylpapaverine and, especially, its glucuronide were found in urine samples of poppy seed consumers even 48 hours after consumption. According to these results PAP metabolites should not be regarded as markers of illicit HER abuse. In conclusion, only acetylcodeine can be regarded as a specific marker but has the problem of a short half-life. Therefore, we suggest that NOS and PAP, but not their metabolites, might be used cautiously as additional markers of illicit HER abuse as they have not been detected after oral intake of poppy seeds in normal doses. But it must be kept in mind that in some cases poppy seeds with an unusually high content of these alkaloids could be available, and that these substances are also agents in some pharmaceuticals.

Detection of non-prescription heroin markers in urine with liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

The planned introduction of a prescription heroin program in Germany created a need for differentiation between non-prescription and prescribed diamorphine use. The following substances were chosen as markers of non-prescription heroin: acetylcodeine (AC); its metabolites codeine (C) and codeine 6-glucuronide (C6G); papaverine (P); and noscapine (N). Typical heroin markers diamorphine (DAM) and its metabolites monoacetylmorphine (MAM) and morphine (M) were also determined. The drugs were extracted from urine samples with solid-phase extraction (C18) using standard 200-mg columns and 96-well microplates (100 mg). The extracts were examined with liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (positive ionization) in two isocratic systems. Selected ion monitoring procedures were applied for protonated molecular masses and characteristic fragments of drugs involved. The limits of detection were in the range of 0.5-1 ng/mL urine. The occurrence of selected heroin markers was investigated in 25 urine samples collected from heroin abusers (road traffic offenders and overdosed patients). C6G was found in all samples, C in 24 samples, N in 22 samples, MAM in 16 samples, P in 14 samples, DAM in 12 samples, and AC in 4 samples. The appearance of these compounds in urine reflects their pharmacokinetic properties and the composition of non-prescription heroin.

Gas chromatographic/mass spectrometric detection of narcotine, papaverine, and thebaine in seeds of Papaver somniferum.

In addition to codeine and morphine, three more compounds: narcotine (noscapine), papaverine, and thebaine were found in Indian and Netherlands poppy seeds (Papaver somniferum L). The compounds were detected by a GC/MS technique and the identities were confirmed by comparing retention times and ion ratios with the known references. The concentrations of codeine, morphine, thebaine, papaverine, and narcotine were 44, 167, 41, 67, and 230 micrograms/g in Indian poppy seeds, and were 1.8, 39, 1.0, 0.17, 0.84 micrograms/g in Netherlands poppy seeds, respectively. Because these compounds may be urinary products after poppy seed consumption, the lowest detectable concentrations of codeine, morphine, thebaine, papaverine, and narcotine in urine are of interest and were found to be 4, 4, 5, 0.4, and 4 ng/ml, respectively. The detection of urinary narcotine, papaverine, or thebaine may be utilized to differentiate poppy seed consumption from illicit codeine, morphine, or heroin use.

[A combination of chromatographic analysis methods in determining narcotic analgesics in biological fluids]. / Sochetanie khromatograficheskikh metodov analiza pri opredelenii narkoticheskikh anal'getikov v biologicheskikh zhidkostiakh.

A combination of instrumental chromatographic methods high pressure liquid chromatography in the isocratic mode and reverse phase thin-layer chromatography with densitometric ending on Russian Sorbton-RP-2 plates--is conducive to a fuller and more reliable identification of narcotic analgesics in biological fluids (blood and urine).

High-performance liquid chromatographic method for the determination of drotaverine in human plasma and urine.

A simple and sensitive HPLC method for the determination of drotaverine in human plasma and urine has been developed. Alkalinized plasma or urine was extracted with organic solvent and the basic components in the organic phase were back-extracted into 0.1 M HCl. An aliquot of the aqueous layer was injected onto the column and the eluent was monitored at 254 nm. Separation was performed on a C18-column with 0.02 M sodium dihydrogen phosphate-methanol (30:70, v/v) containing perchlorate ion at pH 3.2 as mobile phase. Drotaverine was well resolved from the plasma constituents and internal standard. An excellent linearity was observed between peak-height ratios and plasma concentrations and the intra- and inter-assay coefficients of variation were always < 10%. The lowest limit of detection (signal-to-noise ratio 3:1) was 6 ng/ml. The method is suitable for therapeutic monitoring and pharmacokinetic studies of drotaverine in humans as well as in animal models.

The fate of drotaverine-acephyllinate in rat and man. II. Human pharmacokinetics of drotaverine-14C-acephyllinate.

Pharmacokinetics of Drotaverine-Acephyllinate, Chinoin was investigated in seven male volunteers using 14C labelled drug. Drotaverine-Acephyllinate was administered at a 100 mg single oral dose. Measurements of total radioactivity showed that the drug was absorbed completely and was eliminated by renal and biliary routes. Within 72 hours 39.9 +/- 9.9% and 47.1 +/- 4.9% of the dose were recovered in the urine and faeces respectively. Experimental results were interpreted on the basis of a complex linear compartment model. The structural identifiability of the model was proved by computer analysis, and the pharmacokinetic parameters were determined.

The fate of drotaverine-acephyllinate in rat and man. I. Absorption, distribution and excretion in the rat.

Two different labelled forms were used for the pharmacokinetic investigations: the carbon 1 in the isoquinoline ring (Drotaverine-14C-Acephyllinate) and the carboxyl group of theophylline-7-acetic acid (Drotaverine-Acephylline-14C-ate). Drotaverine-14C-Acephyllinate was rapidly absorbed from duodenal and ileal segments. Biliary excretion was substantial after oral administration and radioactivity was excreted mostly in the feces. Absorption of Drotavenine-Acephylline-14-C-ate from the gastrointestinal tract was very poor and radioactivity was therefore excreted for the most part in the feces. The results of the study were confirmed by whole body autoradiography.

Metabolism of papaverine IV. Urinary elimination of papaverine metabolites in man.

1. A gas chromatographic method is described for the quantitative determination of the metabolites of papaverine in urine. 2. The urinary excretion of papaverine metabolites was studied in man. About 50% of the metabolites of papaverine are excreted in the urine within 48 h. 6-Desmethylpapaverine is the major metabolite in the urine. The metabolites are excreted almost completely in conjugated form.

Absorption, distribution and elimination of drotaverine.

14C-drotaverine [1(3',4'-diethoxybenzale)-6, 7-diethoxy-1, 2,3, 4-tetrahydroisoquinoline. HCl; No-SpaR] is well absorbed after subcutaneous and oral administration in mice. Its distribution is not specific. After intravenous administration the drug penetrates rapidly into every organ as indicated by whole body autoradiography. In the first hours the concentration of drotaverine was higher in the intestinal wall than in the other tissues. The concentrations of drotaverine in the organs decrease soon after administration and the drug is excreted mainly with the bile as beta-glucuronide; 60% of the dose was in the bile collected during 5 hours. During 96 hours of observation, 67% of the radioactivity administered was found in the stools while only 20% of it was eliminated with urine.

Determination of papaverine in blood samples by gas-liquid chromatography and mass fragmentography.

The measurement of papaverine in blood samples by using either a glass capillary column with a flame-ionization detector or a packed column with mass fragmentographic detection is described. The two methods permit the determination of the normal range of concentrations of papaverine in blood (2-500 ng/ml). Owing to its high specificity, mass fragmentography is greatly superior to capillary chromatography, which is sometimes subject to interferences by solvent impurities.

Metabolism of papaverine. II. Species differences.

1. The urinary and biliary excretion of radioactive products in a 6 hr period after intravenous administration of [3H]papaverine was studied in rat, guinea-pig, rabbit, cat and dog. All species excreted metabolites extensively in the bile; only in rabbit and guinea-pig is urinary excretion important. 2. Metabolites in urine and bile of all species studied are mainly monophenolic compounds conjugated to glucuronic or sulphuric acid. Differences in the excretion patterns of the metabolites between different species are only quantitative. 3. Blood or plasma levels of papaverine after intravenous injection decreased with half-lives of approximately 12, 15, 22, 60 and 60 min for rabbit, rat, guinea-pig, cat and dog, respectively. The metabolites disappeared much more slowly than papaverine from the plasma. 4. Binding of papaverine to plasma proteins, as studied by equilibrium dialysis, was more than 90% in all species.

Data on the metabolism of benzylisoquinoline derivatives. The metabolism of drotaverin.

Studying the metabolism of drotaverin (No-Spa¿), we have elaborated a method for the isolation, purification and separation of metabolites and of drotaverin excreted in unchanged form in the urine and feces. The structure of the chief metabolites was cleared by t.l.c., polarography, UV spectrophotometry, and mass spectrometry. It was stated that beside drotaverin excreted in unchanged form, the biotransformation of the molecule results in the formation of oxidation and desalkylation products.