Determination of loratadine and pheniramine from human serum by gas chromatography-mass spectrometry

Rapid Characterization of Undeclared Pharmaceuticals in Herbal Preparations by Ambient Ionization Mass Spectrometry for Emergency Care

In Asia, some herbal preparations have been found to be adulterated with undeclared synthetic medicines to increase their therapeutic efficiency. Many of these adulterants were found to be toxic when overdosed and have been documented to bring about severe, even life-threatening acute poisoning events. The objective of this study is to develop a rapid and sensitive ambient ionization mass spectrometric platform to characterize the undeclared toxic adulterated ingredients in herbal preparations. Several common adulterants were spiked into different herbal preparations and human sera to simulate the clinical conditions of acute poisoning. They were then sampled with a metallic probe and analyzed by the thermal desorption-electrospray ionization mass spectrometry. The experimental parameters including sensitivity, specificity, accuracy, and turnaround time were prudently optimized in this study. Since tedious and time-consuming pretreatment of the sample is unnecessary, the toxic adulterants could be characterized within 60 s. The results can help emergency physicians to make clinical judgments and prescribe appropriate antidotes or supportive treatment in a time-sensitive manner.

Simultaneous Determination of Montelukast Sodium and Loratadine by Eco-Friendly Densitometry and Spectrophotometric Methods

Recently, the aim of analytical community is to reduce the usage of hazardous chemicals; so eco-friendly, rapid, selective and cost-effective methods were developed for simultaneous determination of montelukast sodium (MKT) and loratadine (LRT). The first method was based on chromatographic separation performed on precoated silica gel 60 GF254 plates with ethyl acetate-ethanol 9: 1 (v/v) as the mobile phase. The developed plates were scanned and quantified at 260 nm. The method gives linear correlation over concentration ranges of 0.3-3.6 μg/spot and 0.2-4.0 μg/spot for MKT and LRT, respectively. It was also successfully applied to analysis of both drugs in their pharmaceutical preparation and human plasma. The other methods are UV-spectrophotometric methods based on smart spectra manipulating to zero order spectrum of each drug. These methods are named response correlation (RC), a-centering and ratio derivative methods. RC and a-centering methods were dependent on the presence of an isosbestic point between the overlapped spectra of both drugs. While ratio derivative method based on manipulation of the ratio spectra of both drugs. The two drugs obey Beer-Lambert law over the concentration ranges of 3.0-30.0 μg/mL in the three spectrophotometric methods. Moreover, the greenness of the developed methods is assessed using suitable analytical Eco-Scale and Green Analytical Procedure Index.

Thermal desorption ambient ionization mass spectrometry for emergency toxicology

In the emergency department, it is important to rapidly identify the toxic substances that have led to acute poisoning because different toxicants or toxins cause poisoning through different mechanisms, requiring disparate therapeutic strategies and precautions against contraindicating actions, and diverse directions of clinical course monitoring and prediction of prognosis. Ambient ionization mass spectrometry, a state-of-the-art technology, has been proved to be a fast, accurate, and user-friendly tool for rapidly identifying toxicants like residual pesticides on fruits and vegetables. In view of this, developing an analytical platform that explores the application of such a cutting-edge technology in a novel direction has been initiated a research program, namely, the rapid identification of toxic substances which might have caused acute poisoning in patients who visit the emergency department and requires an accurate diagnosis for correct clinical decision-making to bring about corresponding data-guided management. This review includes (i) a narrative account of the breakthrough in emergency toxicology brought about by the advent of ambient ionization mass spectrometry and (ii) a thorough discussion about the clinical implications and technical limitations of such a promising innovation for promoting toxicological tests from tier two-level to tier one level.

Loratadine

Loratadine, 4-(8-Chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylic acid ethyl ester, is an antihistamine drug with long-acting effects and has limited selectivity for peripheral H1 receptors. It is widely used for the prevention of allergic diseases such as rhinitis chronic urticaria, and asthma. This chapter discusses, by a critical extensive review of the literature, the description of loratadine in terms of its names, formulae, elemental composition, appearance, methods of preparation. The profile contains physicochemical properties of Loratadine, including pKa value, solubility and X-ray powder diffraction. In addition, it involves Fourier transform infrared spectrometry, nuclear magnetic resonance spectroscopy and mass spectroscopy for functional groups and structural confirmation of. The chapter also includes methods of analysis of the drug such as compendial, titrimetric, electrochemical, spectroscopic, chromatographic and capillary electrophoretic methods. The chapter also covers clinical applications of the drug such as its uses, doses, ADME profiles and mechanism of action.

Assessment of medication use during pregnancy by Web-based questionnaires, pharmacy records and serum screening

OBJECTIVE

To compare assessment of early pregnancy medication exposure using three methods of data collection.

METHODS

Serum samples were obtained from 752 women participating in the PRegnancy and Infant DEvelopment (PRIDE) Study before gestational week 17. For 52 women using medication at the date of blood sampling according to Web-based questionnaires or pharmacy records, we analysed serum samples using untargeted liquid chromatography time-of-flight spectrometry.

RESULTS

Medication was detected in 18 serum samples (35%). Medications taken orally for chronic conditions reported in the questionnaire were detected in serum and vice versa. Pharmacy records did not identify additional exposed women, but missed exposure in 5 women mainly due to unavailability. We observed substantial discordance between the three methods for inhaled medication, dermatological preparations, and medications for short-term use, which went often undetected in serum.

CONCLUSIONS

It remains challenging to assess medication use in large-scale studies as no 'gold standard' is currently available.

Rapid point-of-care identification of oral medications in gastric lavage content by ambient mass spectrometry in the emergency room

RATIONALE

Acute poisoning should be handled with high efficiency in order to minimize morbidity and mortality in the emergency room. Unfortunately, history-taking and physical examination are not always reliable. Mis-swallowing of oral medications is common in the pediatric group. This study aimed at developing a rapid point-of-care ambient mass spectrometric method for the early identification of ingested oral medications in gastric lavage content.

METHODS

Four different types of oral medications that are most commonly mis-swallowed by children were diluted to different concentrations. Each of these chemical solutions was mixed with human gastric lavage content. A direct metallic sampling probe was dipped into the solution. It was then inserted promptly into the thermal desorption electrospray ionization source to carry out ionization and subsequent mass spectrometric analysis of the medications. The corresponding compounds were identified through matching of the obtained mass spectrometric data with those provided by well-established databases.

RESULTS

Since no pretreatment of the specimen was required, the sampling step, and the subsequent thermal desorption electrospray ionization and mass spectrometric detection of the medications were completed within 30 s. Mass spectra were obtained for four different kinds of oral medication. The limit-of-detection of the four tested oral medications in gastric lavage content is at sub-ppm level, which is sensitive enough for emergency medicine applications since the quantities of medications ingested by pediatric patients are usually much higher.

CONCLUSIONS

Thermal desorption electrospray ionization mass spectrometry, with informational support provided by an online mass spectral database, allows for early point-of-care identification of mis-swallowed oral medications in the evacuated gastric lavage contents obtained from gastric lavage of patients in the emergency room, and it is promising in providing important toxicological information to ensure the appropriateness of the subsequent medical management. Copyright © 2016 John Wiley & Sons, Ltd.

Determination of loratadine and its active metabolite in human plasma by high-performance liquid chromatography with mass spectrometry detection

A new sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS/MS) method for quantification of loratadine (LOR) and its active metabolite descarboethoxyloratadine (DSL) in human plasma was validated. After addition of the internal standard, metoclopramide, the human plasma samples (0.3 ml) were precipitated using acetonitrile (0.75 ml) and the centrifuged supernatants were partially evaporated under nitrogen at 37 degrees C at approximately 0.3 ml volume. The LOR, DSL and internal standard were separated on a reversed phase column (Zorbax SB-C18, 100 mmx3.0 mm i.d., 3.5 microm) under isocratic conditions using a mobile phase of an 8:92(v/v) mixture of acetonitrile and 0.4% (v/v) formic acid in water. The flow rate was 1 ml/min and the column temperature 45 degrees C. The detection of LOR, DSL and internal standard was in MRM mode using an ion trap mass spectrometer with electrospray positive ionisation. The ion transitions were monitored as follows: 383-->337 for LOR, 311-->(259+294+282) for DSL and 300-->226.8 for internal standard. Calibration curves were generated over the range of 0.52-52.3 ng/ml for both LOR and DSL with values for coefficient of determination greater than 0.994 by using a weighted (1/y) quadratic regression. The lower limits of quantification were established at 0.52 ng/ml LOR and DSL, respectively, with an accuracy and precision less than 20%. Both analytes demonstrated good short-term, long-term, post-preparative and freeze-thaw stability. Besides its simplicity, the sample treatment allows obtaining a very good recovery of both analytes, around 100%. The validated LC/MS/MS method has been applied to a pharmacokinetic study of loratadine tablets on healthy volunteers.

Enantioselective determination of pheniramine in pharmaceuticals by capillary electrophoresis with charged cyclodextrin

Cyclodextrin (CD)-mediated capillary zone electrophoresis (CZE) in hydrodynamically closed separation system was developed for the separation and quantitation of pheniramine (PHM) enantiomers. Several parameters affecting the separation were studied, including the type and concentration of chiral selector, carrier cation and counterion, and the pH of the buffer. A high effectivity of oppositely migrating carboxyethyl-beta-cyclodextrin (CE-beta-CD) to separate the PHM enantiomers was demonstrated in detail. The optimized chiral analysis of the antihistamine drug was performed in a buffer consisted of 20 mmol/l epsilon-aminocaproic acid adjusted to pH 4.5 with acetic acid, containing negatively charged CE-beta-CD (2.5 mg/ml) as chiral selector and 0.2% (w/v) methylhydroxyethylcellulose (m-HEC) as an electro-osmotic flow (EOF) suppressor. Acceptable validation criteria for sensitivity, linearity, precision, accuracy/recovery were included. The proposed CZE method was successfully applied to the assay of PHM in pharmaceutical formulations using dioxopromethazine as an internal standard.

Rapid determination of loratadine in small volume plasma samples by high-performance liquid chromatography with fluorescence detection

A simple and rapid high-performance liquid chromatographic method with fluorescence detection was developed for the determination of loratadine in small volume plasma samples. Liquid-liquid extraction of loratadine and diazepam (as internal standard) from plasma samples was performed with n-butyl alcohol/n-hexane (2:98, v/v) in alkaline condition followed by back-extraction into diluted perchloric acid. Chromatography was carried out using a C8 column (250 x 4.6 mm, 5 microm) under isocratic elution with acetonitrile-20 mM sodium dihydrogen phosphate-triethylamine (43:57:0.02, v/v), pH 2.4. Analyses were run at a flow-rate of 1.0 ml/min at room temperature. The method was specific and sensitive with a quantitation limit of 0.62 ng/ml and a detection limit of 0.2 ng/ml at a signal-to-noise ratio of 3:1. The mean absolute recovery of loratadine from plasma was 84%, while the intra-and inter-day coefficient of variation and percent error values of the assay method were all less than 9.7%. Linearity was assessed in the range of 0.62-20 ng/ml in plasma with a correlation coefficient of greater than 0.999. The method has been used to analyze several hundred human plasma samples for bioavailability studies.

Determination of loratadine in human plasma by liquid chromatography electrospray ionization ion-trap tandem mass spectrometry

A sensitive and specific liquid chromatography electrospray ionization ion-trap mass spectrometry (LC-ESI-IT-MS/MS) method has been developed and validated for the identification and quantitation of loratadine in human plasma. After the addition of the internal standard (IS), plasma samples were extracted using isooctane:isoamyl alcohol mixture. The compounds were separated on a prepacked Zorbax phenyl column using a mixture of acetonitrile, 0.20% formic acid as mobile phase. A Finnigan LCQ(DUO) ion-trap mass spectrometer connected to a Waters Alliance high performance liquid chromatography (HPLC) was used to develop and validate the method. The results were within the accepted criteria as stated in the FDA bioanalytical method validation guidance. The method was proved to be sensitive and specific by testing six different plasma batches. Linearity was established for the range of concentrations 0.10-10.0 ng/ml with a coefficient of determination (r(2)) of 0.9998. Accuracy for loratadine ranged from 105.00 to 109.50% at low, mid and high levels. The intra-day precision was better than 10.86%. The lower limit of quantitation (LLOQ) was identifiable and reproducible at 0.10 ng/ml with a precision of 9.84%. The proposed method enables the unambiguous identification and quantitation of loratadine for pharmacokinetic, bioavailability or bioequivalence studies.

Reliable and specific high-performance liquid chromatographic method for simultaneous determination of loratadine and its metabolite in human plasma

A high-performance liquid chromatographic (HPLC) method with fluorescence detection has been developed for the simultaneous determination of loratadine (L) and its metabolite, descarboethoxyloratadine (DCL), in human plasma. Following a two-step liquid-liquid extraction with toluene, the analytes were separated using a gradient mobile phase consisting of methanol-acetonitrile-phosphate buffer. The linearity for L and DCL was within the concentration range of 0.5-16 ng/ml. The coefficient of variation of intra- and inter-day assay was <8.3%, with accuracy ranging from 98.3 to 105.7%. The lower limit of quantification was 0.5 ng/ml for both L and DCL. This method has been demonstrated to be reliable, and is an improvement over existing methods due to its capability for determining L and DCL simultaneously in a single chromatographic run.

Validation of a reversed-phase HPLC method for 1,10-phenanthroline-5,6-dione and analysis of its impurities by HPLC-MS

A reversed-phase HPLC analytical method for the assay of 1,10-phenanthroline-5,6-dione (I) has been developed and validated. A C18 column (150 x 4.6 mm; 5 microm) was employed together with a mobile phase of methanol-water (50:50, v/v) containing 0.1% triethylamine. UV detection was performed at 254 nm. Dione (I) eluted as a spectrally pure peak resolved from its impurities allowing the method to be applied to the purity evaluation of samples obtained via two synthetic routes. In addition, 4,5-diazafluoren-9-one (V) was identified as the main impurity by employing the method in HPLC-MS mode with photodiode array UV detection.

A sensitive LC/MS/MS method using silica column and aqueous-organic mobile phase for the analysis of loratadine and descarboethoxy-loratadine in human plasma

A sensitive method using liquid chromatography with tandem mass spectrometric detection (LC/MS/MS) was developed and validated for the simultaneous analysis of antihistamine drug loratadine (LOR) and its active metabolite descarboethoxy-loratadine (DCL) in human plasma. Deuterated analytes, i.e. LOR-d(3) and DCL-d(3) were used as the internal standards (I.S.). Analytes were extracted from alkalized human plasma by liquid/liquid extraction using hexane. The extract was evaporated to dryness under nitrogen, reconstituted with 0.1% (v/v) of trifluoroacetic acid (TFA) in acetonitrile, and injected onto a 50 x 3.0 mm I.D. 5 microm, silica column with an aqueous-organic mobile phase consisted of acetonitrile, water, and TFA (90:10:0.1, v/v/v). The chromatographic run time was 3.0 min per injection and flow rate was 0.5 ml/min. The retention time was 1.2 and 2.0 min for LOR and DCL, respectively. The tandem mass spectrometric detection was by monitoring singly charged precursor-->product ion transitions: 383-->337 (m/z) for LOR, 311-->259 (m/z) for DCL, 388-->342 (m/z) for LOR-d(3), and 316-->262 (m/z) for DCL-d(3). The low limit of quantitation (LLOQ) was 10 pg/ml for LOR and 25 pg/ml for DCL. The inter-day precision of the quality control (QC) samples was 3.5-9.4% relative standard deviation (R.S.D.). The inter-day accuracy of the QC samples was 99.0-107.9% of the nominal values.

Impurity profile study of loratadine

Three unknown impurities in loratadine bulk drug at levels below 0.1% (ranging from 0.05 to 0.1%) were detected by a simple isocratic reversed-phase high performance liquid chromatography (HPLC). These impurities were isolated from mother liquor sample of loratadine using reversed-phase preparative HPLC. Based on the spectral data (IR, NMR and MS) the structures of these impurities were characterized as 11-(N-carboethoxy-4-piperidylidene)-6,11-dihydro-5H-benzo(5,6) cyclopenta(1,2-b)-pyridine (I), 8-bromo-11-(N-carboethoxy-4-piperidylidene)-6,11-dihydro-5H-benzo(5,6) cyclopenta (1,2-b)-pyridine (II) and 8-chloro-11-(N-carboethoxy-4-piperidylidene)-5H-benzo(5,6) cyclopenta (1,2-b)-pyridine (III). The synthesis of these impurities was discussed.

Capillary electrophoresis determination of loratadine and related impurities

While HPLC has traditionally been the method of choice for purity determination of pharmaceutical substances, capillary electrophoresis (CE) offers a different selectivity and hence it is a complementary technique to HPLC. Loratadine, an antihistamine, could include in its raw material seven impurities that ought to be separated, identified and quantified for drug development and quality control. As a complementary tool for undoubtful identification, a CE method has been developed. The separation was carried out with an uncoated fused-silica capillary (57 cm x 50 microm ID) and was operated at 20 kV potential. Temperature was maintained at 25 degrees C. The final separation buffer was prepared with 100 mM H(3)PO(4) made up to pH 2.5 with NaOH and with 10% acetonitrile added (v/v). Impurities can be detected at the 0.1% level of the active and validation parameters for linearity accuracy and precision are adequate for all the analytes and that permits to consider the method reliable and suitable for application to long-term stability and purity studies.

LC determination of loratadine and related impurities

Loratadine, an antihistamine, could include in its raw material seven impurities that ought to be separated identified and quantified for drug development and quality control. A HPLC method employing a SymmetryShield RP8 column has been developed and validated for loratadine and related compounds measurement, the last ones under the 0.1% level. The mobile phase consisted of methanol-buffer A (65:35, v/v), being buffer A: H(3)PO(4) 10 mM (H(2)O) brought up to pH 7.00 with triethylamine. UV detection was performed at 244 nm. Validation parameters for linearity, accuracy and precision are in agreement with ICH guidelines for all the analytes and that permits to consider the method reliable and suitable for application to long-term stability and purity studies.

Stability indicating methods for the determination of loratadine in the presence of its degradation product

Four stability-indicating procedures have been suggested for determination of the non sedating antihistaminic agent loratadine. Loratadine being an ester undergoes alkaline hydrolysis and the corresponding acid derivative is produced as a degradation product. Its identity was confirmed using IR and MS. The first procedure is based on determination of loratadine by HPLC with detection at wavelength, 250 nm. Mobile phase is acetonitrile:orthophosphoric acid (35:65) using benzophenone as an internal standard. Sensitivity range is 5.00-50.00 microg/ml. Second determination is a densitometric procedure based on determination of loratadine in the presence of its degradate at lambda 246 nm using the mobile phase; methanol:ammonia (10:0.15). Sensitivity range is 1.25-7.50 microg per spot. The third procedure is a spectrophotometric one where a mixture of loratadine and its degradate are resolved by first derivative ratio spectra. Sensitivity range is found to be 3.00-22.00 microg/ml, upon carrying out the measurements at wavelengths 236, 262.4 and 293.2 nm. The fourth procedure is based on second derivative spectrophotometry, where D(2) measurements are carried out at lambda 266 nm. The sensitivity range is 3.00-22.00 microg/ml. The validity of the described procedures was assessed by applying the standard addition technique. Statistical analysis of the results have been carried out revealing high accuracy and good precision. The suggested procedures could be used for determination of loratadine both in pure and dosage forms, as well as in the presence of its degradate.

Polarographic behaviour of loratadine and its direct determination in pharmaceutical formulation and human plasma by cathodic adsorptive stripping voltammetry

The polarographic behaviour of the antihistaminic drug loratadine has been investigated in B.R. buffer solution of different pH values. Contradictory to that mentioned before in a previously published work, loratadine is electro-active at the mercury electrode. In B.R. buffer solution of pH values > or =6 it is reduced via a single 2-electrons irreversible wave corresponding to saturation of carbon-nitrogen double bond of the pyridine ring. The electrode reaction pathway was proposed and discussed. A sensitive differential pulse stripping voltammetric method based on controlled adsorptive accumulation of loratadine on a hanging mercury drop electrode has been developed for its direct determination at nanomolar concentrations without nitration of the drug. The optimized conditions for the direct cathodic adsorptive stripping voltammetric determination of the drug are: 0.1 M sodium hydroxide solution as a supporting electrolyte, accumulation potential, -1.2 V; accumulation time, 30 s; scan rate, 2-5 mV x s(-1) and pulse amplitude 100 mV. The proposed procedure was applied for the assay of loratadine in pharmaceutical formulation and human plasma. The average recoveries were 99.32-99.44 and 100.33-102.99% with the RSD 0.27-0.42 and 0.39-0.90% in pharmaceutical formulation and human plasma, respectively. The limits of detection of 1.60x10(-7) and 1.25x10(-7) M loratadine were found in pharmaceutical formulation and human plasma, respectively.

Determination of loratadine in human plasma by high-performance liquid chromatographic method with ultraviolet detection

A HPLC-UV determination of loratadine in human plasma is presented. After simple liquid-liquid extraction with 2-methylbutane-hexane (2:1) and evaporation of organic phase the compounds were re-dissolved in 0.01 M HCl, evaporated again and finally separated on a Supelcosil LC-18-DB column. The analyses were done at ambient temperature under isocratic conditions using the mobile phase: CH3CN-water-0.5 M KH2PO4-H3PO4 (440:480:80:1, v/v). UV detection was performed at 200 nm with a limit of quantification of 0.5 ng/ml. The precision was found to be satisfactory over the whole range tested (0.5-50 ng/ml) with relative standard deviations of 2.3-6.3 and 5.2-14.1% for intra- and inter-assays, respectively.

Sensitive liquid chromatography–tandem mass spectrometry method for the determination of loratadine and its major active metabolite descarboethoxyloratadine in human plasma

A sensitive method for the simultaneous determination of loratadine and its major active metabolite descarboethoxyloratadine (DCL) in plasma was developed, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted from plasma with toluene followed by back-extraction into formic acid (2%) for DCL after which the toluene containing the loratadine was evaporated, the analyte reconstituted and combined with the DCL back-extract. Chromatography was performed on a Phenomenex Luna C18 (2) 5-microm, 150x2.1-mm column with a mobile phase consisting of acetonitrile-0.1% formic acid using gradient elution (10 to 90% acetonitrile in 2 min) at a flow-rate of 0.3 ml/min. Detection was achieved by a Perkin-Elmer API 2000 mass spectrometer (LC-MS-MS) set at unit resolution in the multiple reaction monitoring mode. TurbolonSpray ionisation was used for ion production. The mean recovery for loratadine and descarboethoxyloratadine was 61 and 100%, respectively, with a lower limit of quantification at 0.10 ng/ml for both the analyte and its metabolite. This is the first assay method described for the simultaneous determination of loratadine and descarboethoxyloratadine in plasma using one chromatographic run. The method is sensitive and reproducible enough to be used in pharmacokinetic studies.