Toddalia asiatica (Linn) Lam (T. asiatica) as a traditional Miao medicine was investigated to find rational alternative medicinal parts for T. asiatica root bark and its antitumor chemical constituents by quantitative pharmacognostic microscopy, high performance liquid chromatography (HPLC) fingerprint and multivariate statistical analysis. A bivariate correlation analysis method based on microscopic characteristics and content of chemical constituents was established for the first time, there were some regular discoveries between powder microscopic characteristics and common chromatographic peaks of T. asiatica through quantitative pharmacognostic microscopy, cork cells, calcium oxalate square crystal, brown clump, starch granule and phloem fiber, as powder microscopic characteristics may be placed where the main chemical constitutes were enriched. Scores plot of principal component analysis (PCA) and dendrogram of hierarchical clustering analysis (HCA) showed that 18 T. asiatica samples were distinguished correctly, clustered clearly into two main groups as follows: S01∼S03 (root bark) and S07∼S09 (stem bark) in cluster 1, S04∼S06 and S10∼S18 in cluster 2. Nineteen common peaks were obtained in HPLC fingerprint of T. asiatica, loadings plot of PCA indicated seven compounds played important roles in different part of samples (P10 > P08 > P07 > P14 > P16 > P17 > P19), peaks 04, 06, 07, 08, 10 were identified as hesperidin, 4-methoxycinnamic acid, toddalolactone, isopimpinlline and pimpinellin. MTT assay was used to determine the inhibitory activity of different medicinal parts of T. asiatica on human breast cancer MCF-7 cells, all parts of T. asiatica had different inhibitory effects on MCF-7 cell lines, root and stem barks of T. asiatica showed the best inhibitory activity. The relationship between chemical constituents and the inhibitions on MCF-7 cell had been established, significant antitumor constituents of T. asiatica were identified by correlation analysis, the order of the antitumor effect of the main compounds was P07 (toddalolactone) > P16 > P06 (4-methoxycinnamic acid), P11 > P18 > P10 (pimpinellin) > P08 (isopimpinellin) > P01 > P19 > P14 > P04 (hesperidin) > P17, which were antitumor chemical constituents of T. asiatica root bark. T. asiatica stem bark was the most rational alternative medicinal part for T. asiatica root bark.
Sodium polystyrene sulfonate (SPS) powder is in use for over 50 years for the treatment of hyperkalemia. SPS powder is official in United States Pharmacopoeia, British Pharmacopoeia and European Pharmacopoeia. However, till date, no study has been published on the assessment of organic impurities for this drug. The organic impurities in bulk drug and finished product are associated with their safety, efficacy and stability. A simple, rapid, specific, precise and an accurate HPLC method has been developed for the estimation of toxic organic impurities like styrene, naphthalene, divinyl benzene (DVB) and ethylvinyl benzene (EVB) from SPS bulk drug and finished product. The developed method was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantitation (LOQ), solution stability, ruggedness and robustness. The influence of acid, alkali, oxidative stress, photolytic stress, thermal stress and humidity stress conditions on SPS bulk powder and finished product has been studied and reported. The proposed method can be successfully employed for the impurity testing of commercial batches of the bulk drug and finished products of both sodium salt and calcium salt of polystyrene sulfonate.
Mono- and bis-pyridinium quaternary aldoximes (K-oximes) have long been employed as cholinesterase reactivator components of antidotes against lethal cholinesterase-inhibiting organophosphorous chemicals. Their positive charge poses difficulties in their chromatographic analysis, resulting in the publication of different approaches for each K-oxime. A multiplexed method is presented for the rapid quantitation of 10 K-oximes in blood with its utility demonstrated in vivo. Liquid chromatography with absorbance detection was employed. Reversed-phase separation was achieved on a highly nonpolar stationary phase. Method validation was based on the respective guideline of the European Medicines Agency. Times to peak concentrations and 120-min areas under the time–concentration curves were determined in rats following intraperitoneal administration. Adequate retention and separation of K-oximes with acceptable peak shapes in short isocratic runs was achieved by adjusting ionic strength, organic content and the concentration of the ion-pairing agent of the mobile phase. Chromatographic properties were governed by optimizing the concentration of dissolved ions. Accurate adjustment of the organic content was indispensable for avoiding peak drifting and splitting. Dose-adjusted exposure to K-347 and K-868 was exceptionally low, while exposure to K-48 was the highest. The method is suitable for screening systemic exposure to various K-oximes and can be extended.
This study presents the optimization and validation of methods for the analysis of retinol, thiamine, niacin, pyridoxine, folic acid, cyanocobalamin, zinc, and iron in fortified kernels (coated and extruded) and in fortified rice. The analyses were performed by HPLC-UV/FLD/MS and ICP-OES. The optimized methods showed good resolution of the analyte peaks, excellent recovery (87–108%), reproducibility with relative standard deviation (SD) of analyte content between 1.8 and 11% and high correlation coefficient of the calibration curves (R2 > 0.997). Limit of detection was from 2.8 E-4 mg/kg for pyridoxine to 1.26 mg/kg for zinc and limit of quantification was from 9.2 E-4 mg/kg for pyridoxine to 4.21 mg/kg for zinc. Thereby the optimized methods demonstrated reliability and sensitivity in the detection and quantification of these micronutrients and that they are suitable for routine analysis of fortified kernels (coated and extruded) and fortified rice.
This study describes the development and validation of a simple, specific, accurate, and precise method for quantitative determination of Esomeprazole in human serum using Pantoprazole as internal standard (IS). After the addition of internal standard, Esomeprazole from serum samples was extracted simply by protein precipitation method followed by centrifugation and the supernatants were directly injected into the high performance liquid chromatography (HPLC). The chromatographic separation of the compounds was obtained on Hitachi Lachrom C8 column (5 µm, 250 × 4.6 mm) with a mobile phase consisting of 5 mM potassium dihydrogen phosphate pH 7.4 and acetonitrile in a ratio of 70:30 with UV detection at 302 nm with a flow rate of 1 mL/min. The method was sensitive and specific, and validated over a concentration range of 0.06–6.0 µg/mL. The limit of detection (LOD) and lower limit of quantification (LOQ) was 0.03 µg/mL and 0.06 µg/mL, respectively. The precision and accuracy expressed as relative standard deviation were less than 15%. The average recovery of Esomeprazole from serum was 97.08%.
A rapid and sensitive High-Performance Liquid Chromatography-tandem Mass Spectrometry (HPLC/MS/MS) method for determining apremilast in beagle dog plasma and urine samples was developed and validated using clopidogrel as the internal standard (IS). Apremilast was extracted from the plasma and urine samples by liquid–liquid extraction using methyl tert-butyl ether. Chromatographic separation was performed using a C8 column with gradient elution and a mobile phase containing methanol and 0.1% formic acid. Quantification was achieved in multiple reaction monitoring (MRM) mode with a transition of m/z 461.3→178.2 for apremilast and m/z 322.2→184.1 for clopidogrel (IS). This method was validated regarding its specificity, linearity, precision, accuracy, and stability. The lower limit of quantification (LLOQ) for this method was 5 ng/mL, and the calibration curve was linear over 5–1,000 ng/mL. The intra- and inter-run coefficients of variance (CV) of aprelimast in plasma samples were less than 12.92% and 10.64%, respectively, while in urine samples, the CV were less than 11.84% and 10.20%, respectively. The samples were stable under the tested conditions. This method was successfully applied to a pharmacokinetic study in beagle dogs following oral administration of 10 mg of apremilast.
Calycanthine is an important class of alkaloids extracted and isolated from the roots, leaves, flowers and fruits of Chimonanthus praecox. In this work, the UPLC-MS/MS method was used for determination of calycanthine in rat plasma, and the pharmacokinetics in rats were investigated. Midazolam was used as an internal standard (IS), and methanol precipitation method was used to pretreatment the rat plasma samples. Chromatographic separation was achieved on a UPLC BEH C18 (50 × 2.1 mm, 1.7 μm) column with the mobile phase of methanol- 0.1% formic acid aqueous solution with gradient elution. Multiple reaction monitoring (MRM) mode with positive ionization was applied for quantitative analysis, m/z 347.3 → 246.7 and 326.2 → 291.4 for calycanthine and IS, respectively. The results indicated that within the range of 1–200 ng/mL, linearity of calycanthine in rat plasma was good (r > 0.995), and the lower limit of quantification (LLOQ) was 1 ng/mL. Accuracy range was between 90.6 and 109.4%, precision (RSD) of calycanthine was less than 14%. The matrix effect was between 97.9% and 105.4%, the recovery was better than 85.6%. The developed UPLC-MS/MS method was successfully applied in the pharmacokinetics of calycanthine in rats after oral and intravenous administration. The absolute bioavailability of the calycanthine was 37.5% in rats.
Twelve Sprague-Dawley rats were randomly divided into two groups: Citrus suavissima Hort. ex Tanaka group and control group (n = 6). The rats in Citrus suavissima Hort. ex Tanaka group were given Citrus suavissima Hort. ex Tanaka juices (1 mL/100 g) by oral administration each day, continued for 14 days; the rats in control group were given Stroke-physiological saline solution (1 mL/100 g) by oral administration each day, continued for 14 days. The rats of these two groups were given a single oral administration of erlotinib (20 mg/kg) on the 15th day. After blood sampling at different time points and processing, the concentrations of erlotinib in rat plasma were determined by the established ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. Chromatographic separation was achieved using a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with erlotinib-d6 as an internal standard (IS). The initial mobile phase consisted of acetonitrile and water (containing 0.1% formic acid) with gradient elution. Multiple reaction monitoring (MRM) modes were utilized to conduct quantitative analysis. The sensitive, rapid and selective UPLC-MS/MS method was successfully applied to analyse the effect of Citrus suavissima Hort. ex Tanaka on pharmacokinetics of erlotinib in rat plasma. There were no significant differences in AUC(0−t), t1/2, Tmax, CL, Cmax between the two groups (P > 0.05). While MRT(0−t) was decreased (P < 0.05) in Citrus suavissima Hort. ex Tanaka group, compared to the control group. It showed that Citrus suavissima Hort. ex Tanaka could not affect the metabolism of erlotinib.
A simple, inexpensive and sensitive method was developed for the simultaneous determination of three pesticide residues (carbendazim, thiophanate-methyl, and imidacloprid) in fruit and vegetable samples using high performance liquid chromatography (HPLC) based on a combined pretreatment of ultrasound-assisted deep eutectic solvent extraction (UA-DES-E) and liquid-liquid extraction (LLE). In this study, various types of deep eutectic solvents (DESs) were synthesized and the extraction efficiency was compared as extraction solvents. Results showed that glycerol-proline = 9:4 (GP-5) obtained the highest extraction efficiency among different types of DESs. Experiment conditions, including DES volume, extraction time and pH, were systematically optimized using single-factor experiment. Under the optimum conditions, the limits of detection (LODs) and quantification (LOQs) were in the ranges of 0.05–0.2 μg·mL−1 and 0.1–0.5 μg·mL−1, respectively. The relative recoveries of the three pesticides in the fruit and vegetable samples ranged from 85.7 to 113.0% at two spiked levels. Meanwhile, the method achieved excellent linearity with determination coefficients (r) greater than 0.999. Furthermore, the method was successfully applied to the analysis of the pesticides in real fruit and vegetable samples (apple, tomato, and grape).
A simple, accurate and sensitive method of high performance liquid chromatography (HPLC) with diode array detector was established to identify Xinfeng capsules and systematically evaluated its quality, based on chromatographic fingerprint integrated with the similarity analysis, hierarchical cluster analysis and the quantitative analysis of multi-components by single marker (QAMS). In this study, 18 peaks were selected as the common peaks to evaluate the similarities among different batches (S1–S10) of Xinfeng capsules samples, which were manufactured in the First Affiliated Hospital of Anhui University of Chinese Medicine with a three-year span. Compared to control fingerprint, the similarities values for 10 batches of samples were more than 0.90. Moreover, by analyzing the reference of astragalus, the chromatogram of astragalus was developed, and 10 common peaks of astragalus were identified. More importantly, simultaneous quantification of three markers in Xinfeng capsule, including Calycosin-7-glucoside, calycosin and Formononetinaldehyde was performed, the three constituents showed good regression (R > 0.999) within linear ranges, and their recoveries were within the range of 97.6–101.5%. The validation results showed that the developed method was specific, accurate, precise and robust. This study demonstrated that the developed method offers an efficient, reliable and practical approach for systematic quality evaluation of Xinfeng capsule.