Sali Cao

Emodin: A Review of its Pharmacology, Toxicity and Pharmacokinetics

Emodin is a natural anthraquinone derivative that occurs in many widely used Chinese medicinal herbs, such as Rheum palmatum, Polygonum cuspidatum and Polygonum multiflorum. Emodin has been used as a traditional Chinese medicine for over 2000 years and is still present in various herbal preparations. Emerging evidence indicates that emodin possesses a wide spectrum of pharmacological properties, including anticancer, hepatoprotective, antiinflammatory, antioxidant and antimicrobial activities. However, emodin could also lead to hepatotoxicity, kidney toxicity and reproductive toxicity, particularly in high doses and with long‐term use. Pharmacokinetic studies have demonstrated that emodin has poor oral bioavailability in rats because of its extensive glucuronidation. This review aims to comprehensively summarize the pharmacology, toxicity and pharmacokinetics of emodin reported to date with an emphasis on its biological properties and mechanisms of action. Copyright

Simultaneous determination and pharmacokinetic study of polyphyllin I, polyphyllin II, polyphyllin VI and polyphyllin VII in beagle dog plasma after oral administration of Rhizoma Paridis extracts by LC-MS-MS.

For the first time, a rapid and specific LC-MS-MS method has been developed for the analysis of polyphyllin I, polyphyllin II, polyphyllin VI and polyphyllin VII in beagle dog plasma. The method was applied to study the pharmacokinetics of Rhizoma Paridis extracts containing polyphyllin I, polyphyllin II, polyphyllin VI and polyphyllin VII. The analysis was carried out on an Agilent Zorbax XDB-C(18) reversed-phase column (100 × 2.1 mm, 1.8 µm) by isocratic elution with acetonitrile and water (50:50, v/v). The flow rate was 0.25 mL/min. All analytes including internal standards were monitored by selected reaction monitoring with an electrospray ionization source. Linear responses were obtained for polyphyllin I, polyphyllin II, polyphyllin VI and polyphyllin VII ranging from 10 to 5000 ng/mL. The intra-and inter-day precisions (RSDs) were less than 6.66 and 9.15%. The extraction recovery ranged from 95.53 to 104.21% with RSD less than 8.69%. Stability studies showed that polyphyllin I, polyphyllin II, polyphyllin VI and polyphyllin VII were stable in preparation and analytical process. The validated method was successfully used to determine the concentration-time profiles of polyphyllin I, polyphyllin II, polyphyllin VI and polyphyllin VII.

Preparation and evaluation of solid dispersions of a new antitumor compound based on early-stage preparation discovery concept.

Ensuring sufficient drug solubility is a crucial problem in pharmaceutical-related research. For water-insoluble drugs, various formulation approaches are employed to enhance the solubility and bioavailability of lead compounds. The goal of this study was to enhance the dissolution and absorption of a new antitumor lead compound, T-OA. Early-stage preparation discovery concept was employed in this study. Based on this concept, a solid dispersion system was chosen as the method of improving drug solubility and bioavailability. Solid dispersions of T-OA in polyvinylpyrrolidone (PVP) K30 were prepared by the solvent evaporation method. Dissolution testing determined that the ideal drug-to-PVP ratio was 1:5. X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry were employed to confirm the formation of solid dispersions. Scanning electron microscopy demonstrated that T-OA was converted into an amorphous form. Both in vitro dissolution testing and the in vivo studies demonstrated that the solubility and bioavailability of T-OA were significantly improved when formulated in a solid dispersion with PVP. The dissolution rate of the T-OA/PVP solid dispersion was greatly enhanced relative to the pure drug, and the relative bioavailability of T-OA solid dispersions was found to be 392.0%, which is 4-fold higher than the pure drug.

In-vitro and in-vivo comparison of T-OA microemulsions and solid dispersions based on EPDC

Abstract The goal of this study was to enhance the absorption of a new water-insoluble antitumor lead compound, T-OA (3β-hydroxyolea-12-en-28-oic acid-3, 5, 6-trimethylpyrazin-2-methyl ester). Early-stage preparation discovery concept (EPDC) was employed in this study. Based on this concept, a microemulsion system was chosen as the method of improving bioavailability. The solubility of T-OA was checked in different oils, surfactants and cosurfactants. Ternary phase diagrams were constructed to evaluate the microemulsion domain. Developed high-performance liquid chromatography method was used to determine drug content. The transparent o/w microemulsion formulation composed of oleic acid (oil), Tween 80 (surfactant), ethanol (co-surfactant) and water enhanced the solubility of T-OA up to 20 mg/mL. It was characterized in terms of appearance, content, viscosity, zeta potential, conductivity, morphology and particle size. The particle size distribution, viscosity, conductivity and zeta potential were found to be 70 nm, 15.57 MPa s, 44.1 μS cm−1 and −0.174, respectively. Oral bioavailability of T-OA microemulsion and oleic acid solution were checked by using rat model. Contrast to the solid dispersion and proto drug, the area-under-the-curve (AUC) of T-OA microemulsion and oleic acid solution were significantly enhanced. The relative bioavailability of T-OA microemulsion was found to be 5654.7%, which is 57-fold higher than the pure drug. Improved T-OA solubility in microemulsion was found sustained 48 h in dilution study. While the solid dispersion may precipitate under the gastrointestinal circumstance based on dilution results. The in-vivo and in-vitro results indicated that, compare to improve the solubility, it is more important to maintain and prolong the T-OA dissolved status, for improvement of the in-vivo absorption.

Development and validation of a highly sensitive LC-ESI-MS/MS method for the determination of hyperoside in beagle dog plasma: application to a pharmacokinetic study.

A highly sensitive, rapid assay method has been developed and validated for the analysis of hyperoside in beagle dog plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive-ion mode. The assay procedure involves extraction of hyperoside and ginsenoside Re (IS) from beagle dog plasma. Chromatographic separation was carried out on an Agilent Zorbax XDB-C18 (100 × 2.1 mm, 1.8 µm) column by isocratic elution with acetonitrile and water (50:50, v/v) at a flow rate of 0.25 mL/min with a total run time of 2.0 min. The MS/MS ion transitions monitored were 464.4 → 463.4 for hyperoside and 947.12 → 969.60 for IS. Linear responses were obtained for hyperoside ranging from 10 to 5000 ng/mL. The intra-and inter-day precisions (RSDs) were <5.38 and 3.39% and the extraction recovery ranged from 94.39 to 100.78% with an RSD <3.82%. Stability studies showed that hyperoside was stable in preparation and analytical process. The results indicated that the validated method was successfully used to determine the concentration-time profiles of hyperoside.

Chemical Constituents from Daphne giraldii Nitsche and Their Contents Simultaneous Determination by HPLC

Daphne giraldii Nitsche (Thymelaeaceae) is widely distributed in the Chinese provinces of Shaanxi, Gansu, and Qinghai, which has been used in Chinese folk medicine to treat ache and rheumatism. Pharmacologic tests have revealed that the plant has anti-inflammatory, analgesic, and anticancer activities. However, there is still not enough systemic investigation on the chemical constituents and the method for the contents simultaneous determination in D. giraldii. Therefore, the isolation and characterization of the compounds from the stem barks of this plant were reported. Moreover, a facile, accurate, and reliable method has been developed and validated for their simultaneous determination using HPLC-DAD.

Simultaneous Determination of Typhaneoside and Isorhamnetin-3-O-Neohesperidoside in Rats After Oral Administration of Pollen Typhae Extract by UPLC–MS/MS

For the first time, a selective and rapid ultra-performance liquid chromatography method with tandem mass spectrometric (UPLC-MS/MS) detection for simultaneous determination of typhaneoside and isorhamnetin-3-O-neohesperidoside in rat plasma was developed and validated, which was applied to the pharmacokinetic study of Pollen Typhae extract. The separation was carried out on an ACQUITY UPLC(TM) BEH C18 column with gradient elution using mobile phase including acetonitrile and water (containing 0.1% formic acid). The flow rate was 0.4 mL/min. The detection was conducted by means of electrospray ionization mass spectrometry in negative ion mode with multiple reaction monitoring. The assays were linear over the concentration range of 0.5-100 ng/mL, and the lower limit of quantification was 0.5 ng/mL for typhaneoside and isorhamnetin-3-O-neohesperidoside. The method was validated in terms of intra- and interday precision (<9.37%), accuracy (within ±10.91%), linearity, specificity and stability, and has been successfully applied to a pharmacokinetic study of Pollen Typhae extract in rats after oral administration.

Simultaneous determination and pharmacokinetic study of polygalaxanthone III, tenuifolin, tenuifoliside A and tenuifoliside C in rat plasma by LC-MS/MS after oral administration

For the first time, a rapid and specific LC-MS/MS method has been developed for the simultaneous analysis of polygalaxanthone III, tenuifolin, tenuifoliside A and tenuifoliside C in rat plasma, and was applied to the pharmacokinetics (PK) studies of those three compounds. The analysis was carried out on an Agilent Eclipse plus C18 reversed-phase column (100 × 4.6 mm, 3.5 μm) by gradient elution with methanol and ammonia (0.01%, v/v). The flow rate was 0.4 mL min−1. All analytes including internal standards (I.S.) were monitored by selected reaction monitoring with an electrospray ionization source. Linear responses were obtained for polygalaxanthone III and tenuifoliside A ranging from 1 to 2000 ng mL−1, and tenuifolin and tenuifoliside C ranging from 2.5 to 2000 ng mL−1. The intra-day and inter-day precisions (RSD) were less than 12.98% and 7.50% respectively. The extraction recovery ranged from 70.06 ± 6.33% to 86.95 ± 5.35%, and I.S. was 77.23 ± 3.68%. Stability studies showed that the accuracies of polygalaxanthone III, tenuifolin, tenuifoliside A and tenuifoliside C ranged from 93.18% to 106.70%. The matrix effects ranged from 91.72 ± 4.80 to 101.84 ± 5.04. The validated method was successfully used to determine the concentration–time profiles of polygalaxanthone III, tenuifolin, tenuifoliside A and tenuifoliside C.

Simultaneous Analysis of Quercetin and Naringenin in Rat Plasma by Liquid Chromatography–Tandem Mass Spectrometry: Application to a Pharmacokinetic Study After Oral Administration

A rapid and specific LC-MS-MS method has been developed for simultaneous analysis of quercetin and naringenin in rat plasma. The method was applied to the pharmacokinetics studies of quercetin and naringenin after oral administration of Pollen Typhae extract. The samples were prepared by the protein precipitation method. The analysis was carried out on an ACQUITY UPLC™ BEH C18 column with gradient elution using mobile phase, which included acetonitrile and water (containing 0.1% formic acid). The flow rate was 0.4 mL/min. All analytes including internal standard (IS) were monitored by selected reaction monitoring with an electrospray ionization source. Linear responses were obtained for quercetin ranging from 0.5 to 100 ng/mL and naringenin ranging from 5 to 1000 ng/mL. The intra- and interday precisions (RSD) were less than 10.78 and 11.20%. The extraction recovery of the analytes was acceptable. Stability studies showed that quercetin and naringenin were stable in the preparation and analytical process. The validated method was successfully used to determine the concentration-time profiles of quercetin and naringenin.

Pharmacokinetics and brain distribution studies of ginsenoside Rd in rats via intranasal administration by LC-MS/MS

Ginsenoside Rd was shown to have protective effects against several injuries and efficient for the treatment of acute ischemic stroke. Some research studies of ginsenoside Rd in the past mainly focused on the pharmacokinetics after intravenous and oral administration. However, we still lack some basic knowledge about the plasma pharmacokinetics and brain distribution of ginsenoside Rd by any other route, such as intranasal administration. It was found that intranasal administration exhibited good brain-targeting. In this study, a sensitive LC-MS/MS method was developed and validated for the determination of ginsenoside Rd in rat plasma and brain tissue. Detection was performed on an ACQUITY UPLC™ BEH C18 column using gradient elution with a flow rate of 0.2 mL min−1. Mass spectrometry was operated in selected reaction monitoring mode using a negative electrospray ionization interface. The method was linear over the concentration range of 1.0–1000 ng mL−1, and the lower limit of quantification was 1.0 ng mL−1 for ginsenoside Rd. The method was validated in terms of specificity, linearity, intra- and inter-day precision (<12.39%), accuracy (within ±10.1%), dilution integrity, recovery, matrix effects and stability, and has been successfully applied to the pharmacokinetic study of ginsenoside Rd in rats after intranasal administration and evaluation of the brain targeting of ginsenoside Rd.