Current Pharmaceutical Analysis - Volume 15, Issue 5, 2019

Introduction: Schizophrenia is seizures accompanied by severe psychotic symptoms, and a steady state of continuation in the form of periods of stagnation. Antipsychotics are now the basis of treatment for schizophrenia and there is no other molecule that is antipsychotic priority in treatment. Antipsychotics can be classified into two groups; dopamine receptor antagonists such as promazine, fluphenazine etc. and serotonin-dopamine antagonists including risperidone, olanzapine, ziprasidone, aripiprazole etc. Materials and Methods: Electrochemical methods have been used for the determination of antipsychotic agent just as used in the determination of many drug agents. Nearly all of the antipsychotics are electroactive and can be analyzed by electrochemical methods. Electroanalytical methods offer generally high sensitivity, are compatible with modern techniques, have low cost, low requirements, and compact design. Among the most commonly used types, there are cyclic voltammetry, differential pulse voltammetry, square wave voltammetry and linear sweep voltammetry. Conclusion: The aim of this review is to evaluate the main line and the advantages and uses of electroanalytical methods that employed for the determination of antipsychotic medication agents used in schizophrenia. Moreover, applications of the methods to pharmaceutical analysis of Antipsychotics upto- date is also summarized in a table.

Background: Cinnarizine, an antihistaminic drug, is commonly formulated in combination with domperidone and with paracetamol for treatment and prevention of motion sickness and migraine. Objective: The aim of this work was to develop new, simple, precise and selective chromatographic methods (RP-HPLC and TLC-densitometric methods) for the determination of these drugs. These methods can be used as analytical tools in the routine examination in quality control laboratories. Methods: The first method was RP-HPLC method, the separation was carried out on an Inertsil® ODS- 3V C18 column (250 mm 4.6 mm, 5 μm) using a mobile phase composed of methanol: acetonitrile (45: 55, v/v) at a flow rate of 1 ml/min. The detection was carried out at 220 nm. The second method was a TLC-densitometric method where the studied components were separated using a developing system composed of toluene: ethyl acetate: methanol: triethylamine (5: 4.3: 0.7: 0.5, v/v/v/v) on TLC silica gel 60 F254 plates, followed by densitometric scanning at 270 nm. Results: In RP-HPLC method, the peaks were sharp and well separated, the retention times were 5.25, 3.48 and 2.78 min, for cinnarizine, domperidone and paracetamol, respectively. Linearity was obtained over the concentration ranges 1-22, 0.75-16.5 and 25-550 μg/ml, for cinnarizine, domperidone and paracetamol, respectively. In TLC-densitometric method, good separation of spots and linear relationships were achieved over the concentration ranges of 0.2-2, 0.15-1.5 and 5-50 μg/spot, for cinnarizine, domperidone and paracetamol, respectively. Method validation was conducted according to ICH guidelines in terms of linearity, accuracy, selectivity, precision and robustness. Conclusion: The developed methods were applied for the determination of the cited drugs in tablets containing binary drug mixtures. The methods are simple and precise and can be used for routine analysis of the labelled drugs in combined dosage forms in quality control laboratories.

Introduction: This study aimed at developing a technology to measure the hardness of Ibuprofen (IBU) tablets and optimize the IBU formulation using Near-infrared (NIR) spectroscopy. Materials and Methods: Tablets (400 mg±5%, 10mm in diameter) consisting of IBU, microcrystalline cellulose SH-103, carboxymethyl starch sodium, magnesium stearate, silicon dioxide were formed of various hardness (2kg, 4kg, 6kg, 8kg, 10kg, 12kg). The reflectance NIR spectra of various tablets were employed to establish 9 calibrations models, which were further used to predict tablet hardness by Partial least squares (PLS) and principal component regression (PCR) analysis. Results and Conclusion: Cross-validation with independent samples shows that PLS is the optimal predictive model. Which R2=0.9832, RSECV=0.334 and RSE=0.0669. This study established a new, simple, rapid, nondestructive and reliable methodology to optimize the IBU tablet hardness.

Introduction: A sensitive analytical method based on functionalized multi walled carbon nanotubes reinforced hollow fiber solid/liquid phase microextraction (F-MWCNTs-HF-SLPME) forwarded with HPLC-DAD for analyzing phenazopyridine from urine is presented. Materials and Methods: The extraction of phenazopyridine is performed using specially designed FMWCNTs- HF-SLPME device constructed as follows: the functionalized multi walled carbon nanotubes (F-MWCNTs) were immobilized into the pores of 2.5 cm hollow fiber micro-tube using capillary forces and ultrasonication, then, the lumen of the micro-tube was filled with 1-octanol with two ends sealed. Subsequently, the device was placed into 10-mL of urine sample containing the analyte with agitation. After ending extraction, the device was removed, rinsed, sonicated in 250 μL of organic solvent and analyzed directly by the separation system. Results and Conclusion: Different parameters affecting the performance of the developed method were optimized. The method showed good linearity with (R2) 0.999 and good repeatability with (RSDs) from 3.7 to 0.9% at analyte concentration ranged from 0.01 to 10 μg L-1 of spiked urine samples. The limit of detection/ quantitation, LODs/LOQs was 0.02/0.09 μg L-1. In comparison with reference methods, the developed method is considered as a promising microextraction technique for determination of trace phenazopyridine in human urine using a common HPLC without further cleanup procedures.

Background: The quality control indexes detected by the existing methods are less and lack specificity, and cannot truly reflect their intrinsic quality because of the similarity of Schisandra chinensis and Schisandra sphenanthera in both their appearance and their main chemical composition. Therefore, it is urgent to establish an effective method for the quality control of the both. High-performance capillary electrophoresis (HPCE) method was used to establish the fingerprints of Schisandra medicinal materials. Methods: The HPCE was performed, in which a 50μm x 50cm (the effective length was 41.5cm) uncoated fused silica capillary column was applied, the buffer solution was 10 mM phosphate buffer (pH 8)-37.5 mM SDS-35% acetonitrile (v/v), the working voltage was 28 kV, the temperature was 25°C, the samples were injected at 50mbar pressure for 3s, and the detection wavelength was 214nm. The chromatographic fingerprints of samples were analyzed using “traditional Chinese medicine chromatographic fingerprint similarity evaluation system 2004A version” software and cluster analysis. Results: 10 common peaks were confirmed and 8 components were identified in the HPCE fingerprints of 20 batches of Schisandra chinensis and Schisandra sphenanthera, and the results of clustering were consistent with those of similarity evaluation. Conclusion: This method should be accurate and reliable, and can provide a scientific basis for the quality evaluation of Schisandra medicinal materials.

Background: Erding granule (EDG) widely used as an agent with the effect of heat-clearing, detoxifying, eliminating dampness, relieving jaundice and upper respiratory tract disease in clinical application, but the systematic chemical information and anti-hyperuricemia effect of EDG was still unclear. Methods: An ultra-high performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC/ESI-Q-TOF-MS/MS) method was utilized to rapidly identify the chemical constituents of EDG. The anti-hyperuricemia effect of EDG was evaluated based on the effect on xanthine oxidase inhibitory activity (in vitro) and lowering uric acid (in vivo). Results: 198 compounds were tentatively separated and identified or characterized within 30 min by UHPLC/ESI-Q-TOF MS/MS. These compounds were categorized as 22 coumarins, 38 flavones, 67 alkaloids, 36 organic acids, 16 sesquiterpenes, 14 lignans and 5 the others constituents. Meanwhile, EDG significantly decreases the serum urate level of hyperuricemic mice induced by potassium oxonate, while EDG did not significantly decrease the serum urate level of hyperuricemic mice induced by hypoxanthine and activity of xanthine oxidase in vitro. Conclusion: The method developed was rapid and sensitive to characterize the chemical constituents of EDG, and provide a systematic view of chemical information for EDG. Furthermore, we first discovered the anti-hyperuricemia effect of EDG and it would further provide the reference for clarifying the mechanism of EDG on lowering uric acid.

Background: Aminoglycosides are non-chromophoric antibiotics. The official method of assay in pharmacopoeias is microbiological. Bioassay methods are potency-semi-quantitative, laborious and time-consuming. In contrast, spectrophotometric methods are rapid, convenient, specific, sensitive and selective. The presence of NH2 and -OH functional groups in aminoglycosides makes them susceptible to redox reaction. Objective: A simple, cheap, quick, accurate and reliable spectrophotometric method for aminoglycoside analysis using neomycin as prototype via oxidation by ammonium molybdate reagent is proposed. Methods: Four aminoglycosides - amikacin, gentamicin, neomycin and streptomycin, were oxidized using ammonium molybdate (pH<2). These were scanned to obtain visible-spectrophotometric fingerprints. Two assay methods were developed. Method I involved the determination of the drug via the linear proportionality between neomycin and residual molybdate measured at 780nm and 850nm. Method II, an indirect determination using ion-pair reaction of excess molybdate and methyl orange measured at 430nm and 480nm. Results: All aminoglycosides formed blue complex, with distinct spectra peaks at 500nm, 640nm, 780nm and 850nm.The limit of detection and limit of quantification were from 0.33 to 2.32 μgmL-1 and 1.00 to 7.03 μgm L-1 respectively for both methods. Percentage recoveries ranged from 89.60 and 113.05 %, while precision and accuracy as RSD ranged from 0.23 to 3.55%. The regression coefficient (R2) ranged from 0.9968 to 0.9995. Percentage neomycin in dosage forms ranged from 95.67- 104.16% and 96.04 - 99.46% for methods I and II, respectively. Conclusion: The methods were successfully applied for neomycin sulphate determination in tablets and drops, therefore aminoglycosides could be assayed via the proposed methods.

Background: Magnoliae Officinalis Cortex is a well-known traditional Chinese herbal medicine with vast clinical consumption owing to its positive effects. However, little attention has been devoted to analyzing the dynamic changes of the chemical constituents of Magnoliae Officinalis Cortex in different growth periods. Methods: In this study, all analyses were performed on UFLC -20ADXR system and a SynergiTM Hydro-RP 100 Å column (100 mmx2.0 mm, 2.5μm). The mobile phase consisted of water containing 0.1% formic acid (A) and acetonitrile containing 0.1% formic acid (B). The target constituents, including two lignans, two alkaloids, two flavonoids, one phenylpropanoid glycoside, and one organic acid, were analyzed in both positive and negative ion modes with accurate and sensitive multiple reaction monitoring (MRM) mode. Results: The correlation coefficients of all the calibration curves were higher than 0.9992. Relative standard deviations of intra- and inter-day precisions of the eight analytes were all lower than 4.01% and the recoveries were in the range from 98.62% to 102.46%. Grey relational analysis was performed to evaluate the samples according to the contents of 8 constituents. The results showed that the quality of Magnoliae Officinalis Cortex collected at traditional harvest time was much better, and the higher the age, the better the quality. Conclusion: The proposed method is useful for the assessment on the quality of Magnoliae Officinalis Cortex, and this study provides the basis for exploring the quality forming mechanism of Magnoliae Officinalis Cortex medicinal materials and choosing the suitable harvesting period.

Introduction: A rapid, and accurate Ultra Performance Liquid Chromatography (UPLC) method was developed to simultaneously analyze Methocarbamol, Paracetamol and the related substances. Materials and Methods: Waters ACQUITY UPLC® BEH Phenyl C18 column was used in conjunction with UV detection at 225nm. Gradient elution with 0.05M, pH 6 phosphate buffer and acetonitrile flow at 0.3mL /min rate were used to separate the substances. The retention times for 4-Aminopheno, Paracetamol, Guaifenesin, Methocarbamol, and 4-Chloroacetanilide were 1.319 minute, 2.224 minute, 4.467 minute, 4.769 minute and 5.433 minute respectively. The concentration was linear in the range of 2-100 μg/ml for Methocarbamol, and 1-100 μg/mL for Paracetamol. The percentage recoveries were between 99.28±1.23% to 100.57±0.99% for Methocarbamol, and between 99.08±1.23% to 101.23±1.39% for Paracetamol. Results and Discussion: The validated optimal protocol is robust and accurate for simultaneous analysis of Methocarbamol, Paracetamol and the related substances, applicable for bulk powder as well as pharmaceutical formulation. Conclusion: In this paper, a highly sensitive, accurate, and precise UPLC method with UV-Vis detection was developed and validated for quality control of MET and PAR in bulk as well as in pharmaceutical preparations.

Background: Amikacin sulfate (AMK) belongs to the class of aminoglycoside antibiotics. It is effective against the infections caused by Gram-negative and positive bacteria. AMK lacks a chromophore group in its structure and, therefore, it does not absorb light in the 200-800 nm region which makes it a difficult molecule to analyze by UV detector using high performance liquid chromatography (HPLC). Objective: This study has been carried out to develop and validate a relatively simple, accurate, precise, rapid, economical, and stability-indicating pre-column derivatization HPLC method for the determination of AMK in pure and parenteral dosage forms. Methods: The stock solution of AMK was derivatized prior to its analysis. The mobile phase used for the analysis was acetonitrile and water in the ratio of 50:50 (v/v) at pH 6.0. The method has been validated according to the guideline of International Council for Harmonization (ICH) and different parameters such as linearity, range, accuracy, precision, sensitivity, robustness, solution stability, specificity and system suitability have been studied. AMK was subjected to stress degradation studies including thermolysis, humidity exposure, acid-base hydrolysis, and oxidation in order to determine the specificity of the test method. Results: The retention time of AMK has been found to be 4.7 min. The results indicated that the method is linear in the concentration range of 12.5-125% and possesses high accuracy (99.88±0.42%), precision (<1.2%) and robustness (<0.5%). The obtained results are compared statistically with a reference method. Conclusion: It was observed that the stress degradation studies do not affect the accuracy of the method. Hence the proposed method can be used for the assay of AMK and its parenteral dosage form.

Background: Topiramate (TPM), an anticonvulsant drug, was determined in human serum and in umbilical cord blood. TPM can produce severe damage to the fetus (baby into mother´s uterus), and it is not always possible that epileptic women change their drug during pregnancy, because some antiepileptic drugs are not effective on some people. Using pregnant-mother serum blood, we can estimate drug levels in fetus serum, and by umbilical cord blood, is possible estimate drug levels in serum babies, without the ethic aspects to withdrawal blood of them. Methods: Quantitation was achieved by LC/DAD, using liquid-liquid extraction for isolation of TPM from both biological fluids, using dichloromethane as extraction solvent, and dabsyl chloride as derivatizing agent. Results: The method was linear over the concentration range of 5.0 to 20.0 μg/mL for TPM in human serum, and between 1.6-50.0 μg/mL for TPM in umbilical cord blood (r=0.999 and r= 0.998, respectively). RSD, for intra-assay study, was between 0.64%- 1.22% (n=3), and between 0.57% -1.86% (n=9) for inter-assay, when the biological fluid was human serum, and between 0.33% - 3.44%, and 3.38% -3.73%, respectively, when the matrix was umbilical cord blood. LOD was 0.40 μg/mL and 0.39 μg/mL for TPM in human serum and in umbilical cord, respectively, whereas LOQ was 1.20 μg/mL and 1.18 μg/mL, in each biological fluid. Recovery percentage for the accuracy study was between 94.0% and 109.8% (RSD ≤0.191). Conclusion: The method is precise, accurate, reproducible and selective for level analysis of TPM in both matrices.

Background: Monitoring of DA, in the presence of other chemical analogues such as epinephrine, norepinephrine, serotonin, ascorbic acid, uric acid, catechol, phenethylamine, tyramine, and tyrosine, is crucial in the diagnosis and mechanistic understanding of human neuropathology. Therefore, the determination of DA at trace levels has become a very important analytical task, as part of health safety and forensic analysis. Introduction: A cloud point extraction (CPE) process was developed for the isolation and detection of dopamine in food, urine, and pharmaceutical samples. Methods: In this procedure, dopamine was derivatized with o-phthalaldehyde (OPA) and sodium sulphite in aqueous solution. The isoindole derivative was synthesized by the reaction of OPA and sodium sulphite with the amino group of dopamine and the resulted isoindole derivatives were extracted by cloud point extraction. After extraction process, the concentration of enriched analyte was measured by UV-VIS spectrophotometry. The parameters affecting the CPE such as concentration of surfactant and electrolyte, equilibration temperature and time and pH of sample solution were investigated. Results: After optimization of the CPE conditions, the linear range of 8-80 μM (without extraction 100- 1000 μM) was established for dopamine with detection limit at 2.6 μM. Conclusion: The developed extraction procedure was applied to the quantification of dopamine in chocolate, urine, and pharmaceutical samples. The study ensures a promising strategy for the detection of dopamine in the presence of biological constituents, e.g. ascorbic acid, uric acid, and serotonin.

Background: Developing a simple analysis method for quantification of drug concentration is one of the essential issues in pharmacokinetic and therapeutic drug monitoring studies. Objective: A fast and reliable dispersive liquid-liquid microextraction procedure was employed for preconcentration of verapamil in exhaled breath condensate (EBC) samples and this was followed by the determination with high-performance liquid chromatography-ultraviolet detection. Methods: A reverse-phase high-performance liquid chromatography (RP-HPLC) combined with a dispersive liquid-liquid microextraction method (DLLME) was applied for quantification of verapamil in the EBC samples. The developed method was validated according to FDA guidelines. Results: Under the optimum conditions, the method provided a linear range between 0.07 and 0.8 μg.mL-1 with a coefficient of determination of 0.998. The intra- and inter-day relative standard deviation and relative error values of the method were below 15%, which indicated good precision and accuracy. The proposed method was successfully applied for the analysis of verapamil in two real samples with concentrations of 0.07 and 0.09 μg.mL-1. Conclusion: The established HPLC-UV-DLLME method could be applied for the analysis of verapamil in human EBC samples.

Background: Xanthium sibiricum is a well-known traditional Chinese medicine (TCM) that has been commonly used to treat rhinitis and related nasal diseases. The aim of this study was to develop a comprehensive analytical method based on high-performance liquid chromatographyelectrospray ionization coupled with triple quadrupole-linear ion trap mass spectrometry (LC-ESIQTRAP- MS/MS) for the simultaneous determination of phenolic acids, anthraquinones, and flavonoids in the aerial part and fruit of Xanthium sibiricum. Methods: The separation was completed on Agilent ZORBAX SB-C18 column (250 × 4.6 mm, 5μm) using methanol and 0.2% (v/v) aqueous formic acid as the mobile phase. The target components were analyzed in negative ion mode with accurate and sensitive multiple reaction monitoring (MRM) mode. Results: The correlation coefficients of all the calibration curves were higher than 0.9994. Relative standard deviations of intra- and inter-day precisions of the eighteen components were all lower than 2.87% and the recoveries were in the range from 97.73% to 101.82%. The validated method was successfully applied to possess forty Xanthium sibiricum samples (Xanthii Herba, Xanthii Fructus, and processed Xanthii Fructus) collected from different places in P. R. China. Furthermore, principal component analysis (PCA) was performed to evaluate and classify the samples according to the contents of the eighteen bioactive components. Conclusion: All the results demonstrated that the developed method was useful and could be applied for the overall assessment of the quality of Xanthii Herba and Xanthii Fructus.

Introduction: Macitentan is an endothelin receptor antagonist drug used in the treatment of pulmonary arterial hypertension. Materials and Methods: A new, sensitive, simple, accurate and rapid ultra-performance liquid chromatography in combination with tandem triple quadruple mass spectrometry (UPLC-MS/MS) method has been developed and validated for the determination of macitentan in pharmaceutical formulations. Macitentan and bosentan which are used as internal standard (IS) were detected using atmospheric pressure chemical ionization (APCI) in positive ion, multiple reaction monitoring (MRM) mode by monitoring mass transitions (precursor to product) m/z 589.1→203.3 and 552.6→311.5, respectively. Chromatographic separation was carried out on reverse phase C18 column (5 μm, 4.6 * 150 mm). Water containing 0.2 % acetic acid in acetonitrile (10:90, v/v) was used as the mobile phase in the isocratic elution. The system was optimized with injection volume of 10 μL, column temperature of 35 °C and flow rate of 1 mL min-1 Retention times were 1.97 min for macitentan and 1.72 min for IS. Results and Discussion: The calibration curve with a high correlation coefficient (0.9997) was linear range 0.5-500 ng mL-1. The lower limit of quantitation (LLOQ) and average recovery values were determined as 0.5 ng mL-1 and 99.7 %, respectively. The developed novel method has been successfully applied for the determination of macitentan in pure form and pharmaceutical formulations. Conclusion: The present method is the first study developed and validated for the determination of macitentan from the pharmaceutical preparations and pure form by UPLC-MS/MS method in the literature.