Ultrasonication-aided synthesis of nanoplates-like iron molybdate: Fabricated over glassy carbon electrode as an modified electrode for the selective determination of first generation antihistamine drug promethazine hydrochloride.

The innovation of novel and proficient nanostructured materials for the precise level determination of pharmaceuticals in biological fluids is quite crucial to the researchers. With this in mind, we synthesized iron molybdate nanoplates (Fe2(MoO4)3; FeMo NPs) via simple ultrasonic-assisted technique (70 kHz with a power of 100 W). The FeMo NPs were used as the efficient electrocatalyst for electrochemical oxidation of first-generation antihistamine drug- Promethazine hydrochloride (PMH). The as-synthesized FeMo NPs were characterized and confirmed by various characterization techniques such as XRD, Raman, FT-IR, FE-SEM, EDX and Elemental mapping analysis and electron impedance spectroscopy (EIS). In addition, the electrochemical characteristic features of FeMo NPs were scrutinized by electrochemical techniques like cyclic voltammetry (CV) and differential pulse voltammetry technique (DPV). Interestingly, the developed FeMo NPs modified glassy carbon electrode (FeMo NPs/GCE) discloses higher peak current with lesser anodic potential on comparing to bare GCE including wider linear range (0.01-68.65 µM), lower detection limit (0.01 µM) and greater sensitivity (0.97 µAµM-1cm-2). Moreover, the as-synthesized FeMo NPs applied for selectivity, reproducibility, repeatability and storage ability to investigate the practical viability. In the presence of interfering species like cationic, anionic and biological samples, the oxidation peak current response doesn't cause any variation results disclose good selectivity towards the detection of PMH. Additionally, the practical feasibility of the FeMo NPs/GCE was tested by real samples like, commercial tablet (Phenergan 25 mg Tablets) and lake water samples which give satisfactory recovery results. All the above consequences made clear that the proposed sensor FeMo NPs/GCE exhibits excellent electrochemical behavior for electrochemical determination towards oxidation of antihistamine drug PMH.

A Study of Opiate, Opiate Metabolites and Antihistamines in Urine after Consumption of Cold Syrups by LC-MS/MS.

Studying the origin of opiate and/or opiate metabolites in individual urine specimens after consumption of cold syrups is vital for patients, doctors, and law enforcement. A rapid liquid chromatography-tandem mass spectrometry method using "dilute-and-shoot" analysis without the need for extraction, hydrolysis and/or derivatization has been developed and validated. The approach provides linear ranges of 2.5-1000 ng mL-1 for 6-acetylmorphine, codeine, chlorpheniramine, and carbinoxamine, 2.5-800 ng mL-1 for morphine and morphine-3-ß-d-glucuronide, and 2.5-600 ng mL-1 for morphine-6-ß-d-glucuronide and codeine-6-ß-d-glucuronide, with excellent correlation coefficients (R2 > 0.995) and matrix effects (< 5%). Urine samples collected from the ten participants orally administered cold syrups were analyzed. The results concluded that participants consuming codeine-containing cold syrups did not routinely pass urine tests for opiates, and their morphine-codeine concentration ratios (M/C) were not always < 1. In addition, the distribution map of the clinical total concentration of the sum of morphine and codeine against the antihistamines (chlorpheniramine or carbinoxamine) were plotted for discrimination of people who used cold syrups. The 15 real cases have been studied by using M/C rule, cutoff value, and distribution map, further revealing a potential approach to determine opiate metabolite in urine originating from cold syrups.

Bioanalysis of antihistamines for clinical or forensic purposes.

Antihistamines are a class of drugs that inhibit the action of histamine and are used to alleviate symptoms associated with allergic reactions, but some of them can cause side effects, the most unpleasant and dangerous of which are the sedative effects that may hinder important psychological functions and impair skilled performance. These side effects could decrease safety in certain common and critical tasks, such as driving or operating machinery, leading to accidents. Antihistamines can also cause intoxications, sometimes lethal, especially when co-administered with alcohol or other sedative drugs. Thus, the development of analytical methods for their determination in biological fluids is considered to be useful for the investigation of clinical and forensic cases. These methodologies could also be used for pharmacokinetic studies. Several liquid and a few gas chromatographic methods have been developed for the determination of antihistamines in biological matrices after proper pretreatment procedures. This article reviews the published analytical methodologies that were gathered through the search in PubMed database and the recent developments on isolation or determination of antihistamines in biological materials. Current trends and future perspectives on bioanalysis of antihistamines are also discussed. Copyright © 2016 John Wiley & Sons, Ltd.

Trace analysis of three antihistamines in human urine by on-line single drop liquid-liquid-liquid microextraction coupled to sweeping micellar electrokinetic chromatography and its application to pharmacokinetic study.

A rapid and efficient dual preconcentration method of on-line single drop liquid-liquid-liquid microextraction (SD-LLLME) coupled to sweeping micellar electrokinetic chromatography (MEKC) was developed for trace analysis of three antihistamines (mizolastine, chlorpheniramine and pheniramine) in human urine. Three analytes were firstly extracted from donor phase (4 mL urine sample) adjusted to alkaline condition (0.5 M NaOH). The unionized analytes were subsequently extracted into a drop of n-octanol layered over the urine sample, and then into a microdrop of acceptor phase (100 mM H(3)PO(4)) suspended from a capillary inlet. The enriched acceptor phase was on-line injected into capillary with a height difference and then analyzed directly by sweeping MEKC. Good linear relationships were obtained for all analytes in a range of 6.25 × 10(-6) to 2.5 × 10(-4)g/L with correlation coefficients (r) higher than 0.987. The proposed method achieved limits of detections (LOD) varied from 1.2 × 10(-7) to 9.5 × 10(-7)g/L based on a signal-to-noise of 3 (S/N=3) with 751- to 1372-fold increases in detection sensitivity for analytes, and it was successfully applied to the pharmacokinetic study of three antihistamines in human urine after an oral administration. The results demonstrated that this method was a promising combination for the rapid trace analysis of antihistamines in human urine with the advantages of operation simplicity, high enrichment factor and little solvent consumption.

Chemometrics optimization of six antihistamines separations by capillary electrophoresis with electrochemiluminescence detection.

This work expanded the knowledge of the use of chemometric experimental design in optimizing of six antihistamines separations by capillary electrophoresis with electrochemiluminescence detection. Specially, central composite design was employed for optimizing the three critical electrophoretic variables (Tris-H(3)PO(4) buffer concentration, buffer pH value and separation voltage) using the chromatography resolution statistic function (CRS function) as the response variable. The optimum conditions were established from empirical model: 24.2mM Tris-H(3)PO(4) buffer (pH 2.7) with separation voltage of 15.9 kV. Applying theses conditions, the six antihistamines (carbinoxamine, chlorpheniramine, cyproheptadine, doxylamine, diphenhydramine and ephedrine) could be simultaneous separated in less than 22 min. Our results indicate that the chemometrics optimization method can greatly simplify the optimization procedure for multi-component analysis. The proposed method was also validated for linearity, repeatability and sensitivity, and was successfully applied to determine these antihistamine drugs in urine.

Electro-oxidation and determination of antihistamine drug, cetirizine dihydrochloride at glassy carbon electrode modified with multi-walled carbon nanotubes.

A multi-walled carbon nanotube (MWCNT) film-modified glassy carbon electrode (GCE) was constructed for the determination of an antihistamine drug, cetirizine dihydrochloride (CTZH) using cyclic voltammetry (CV). Owing to the unique structure and extraordinary properties of MWCNT, the MWCNT film has shown an obvious electrocatalytic activity towards oxidation of CTZH, since it facilitates the electron transfer and significantly enhances the oxidation peak current of CTZH. All experimental parameters have been optimized. Under the optimum conditions, the oxidation peak current was linearly proportional to the concentration of CTZH in the range from 5.0×10(-7) to 1.0×10(-5)M. The detection limit was 7.07×10(-8)M with 180s accumulation. Finally, the proposed sensitive and simple electrochemical method was successfully applied to CTZH determination in pharmaceutical and urine samples.

Simple analysis of diphenylmethane antihistaminics and their analogues in bodily fluids by headspace solid-phase microextraction-capillary gas chromatography.

Thirteen antihistaminic drugs and their analogues are tested for their extraction by headspace solid-phase microextraction from human whole blood and urine. Their determination is made by using capillary gas chromatography with flame ionization detection. Relatively high recoveries are obtained for terodiline, diphenhydramine, diphenylpyraline, and orphenadrine in urine; but the recoveries in blood extracts are 4-51 times lower than those in urine extracts for all drugs. Benactyzine and piperilate are not suited for the extraction method. The calibration curves are drawn for four drugs spiked to whole blood and for eleven drugs spiked to urine; excellent linearity is confirmed for the drugs. The detection limits for the drugs are 76-473 ng/mL in blood and 13-186 ng/mL in urine. Diphenhydramine is determined for whole blood obtained from a male subject who had received oral administration of 30 mg diphenhydramine-HCl 150 min before the sampling; the concentrations of the drug are 0.12 and 1.22 micrograms/mL for blood and urine, respectively.

Application of radioreceptor assays for systematic toxicological analysis--1. Procedures for radioreceptor assays for antihistaminics, anticholinergics and benzodiazepines.

Radioreceptor assays can be a useful tool for systematic toxicological analysis in that they can be applied for the detection of an entire pharmacological class of drugs. In the present paper procedures for radioreceptor assays for benzodiazepines, anticholinergics and antihistaminics have been described in detail. The development of the assay for antihistaminics in urine is given in order to illustrate the prerequisites for these types of assays with regard to the incubation conditions. In part 2 the applicability of the three assays for systematic toxicological analysis will be evaluated on the basis of testing a large number of urine samples after administration of a selected number of drugs to healthy volunteers and patients.

Application of radioreceptor assays for systematic toxicological analysis--2. Theoretical considerations and evaluation.

In this paper the applicability of radioreceptor assays for systematic toxicological analysis will be evaluated on a theoretical basis as well as on the basis of the outcomes of the analysis of a large number of urine samples collected after administration of a selected number of drugs to healthy volunteers and patients. Many drugs and other substances of toxicological relevance exert their action through an interaction with one or more receptor (sub)types. Whether the number of persons are using particular drugs intentionally or unintentionally, radioreceptor assays can be a useful tool for systematic toxicological analysis in that they can be applied to the identification of entire pharmacological classes of substances as well as pharmacologically active metabolites. In part 1 of this paper detailed procedures for radioreceptor assays for benzodiazepines, anticholinergics and antihistaminics have been described in detail in order to illustrate not only the potentials but also the limitations of assay conditions. Fifteen drugs were administered to patients and volunteers and urine samples were collected and determined with the three radioreceptor assays. The results of this study underline the theoretical applicability of receptor assays in systematic toxicological analysis though sample pretreatment procedures may contribute to an improvement in sensitivity and applicability to other biofluids.

Positive- and negative-ion mass spectrometry of diphenylmethane antihistaminics and their analogues and rapid clean-up of them from biological samples.

Positive-ion electron impact (PIEI), positive-ion chemical ionization (PICI) and negative-ion chemical ionization (NICI) mass spectra are presented for 15 compounds of diphenylmethane antihistaminics and their analogues, and each fragmentation pathway was analyzed. In the PIEI mode, molecular peaks were very small or missing for most compounds. Peaks at m/z 58, due to a dimethylaminomethyl group liberated, constituted base peaks in five compounds. Peaks at m/z 165 and/or 167, due to diaromatic rings plus a methyl group, appeared in most compounds. In the PICI mode, peaks due to M+H and M+C2H5 appeared in all compounds. Peaks due to diaromatic rings plus a methyl or ethyl group constituted base peaks in five compounds, which had an ether bond in their structures. In the NICI mode, anions at m/z M-H appeared in most compounds. Peaks at m/z 35 were observed for compounds having a chlorine group in their structures. Detection limits for total ion monitoring of these compounds were 20-50 ng on column in the PIEI mode, 100-200 ng in the PICI mode and 500-1000 ng in the NICI mode. A rapid and simple clean-up procedure of these drugs with use of Sep-Pak C18 cartridges is also presented. The drugs could be detected by gas chromatography with DB-1 and DB-17 capillary columns with satisfactory separation from impurities in their underivatized forms. The recovery of the drugs, which had been added to whole blood and urine, was more than 60% except for meclizine.

[Biotransformation and pharmacokinetics of bamipine in rats. 1. biotransformation]. / Biotransformation und Pharmakokinetik von Bamipin an Ratten. 1. Mitteilung: Untersuchungen zur Biotransformation.

Biotransformation and Pharmacokinetics of Bamipine in Rats/1st Communication: Biotransformation studies. The metabolism of the antihistaminic N-phenyl-N-benzyl-4-amino-1-methylpiperidine (bamipine) was investigated after oral application in Wistar rats. The major metabolites in the urine were the ether glucuronides of N-p-hydroxy-phenyl-N-benzyl-4-amino-1-methylpiperidine and of N-p-hydroxyphenyl-N-benzyl-4-amino-piperidine. Unchanged drug was not detected. In vitro studies showed, in good correlation with in vivo studies, a oxidative demethylation of bamipin.