A UPLC-MS/MS method for simultaneous determination of danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine in rat plasma, and its application to pharmacokinetic studies of Shenxiong glucose injection in rats

Development of simultaneous quantitative analytical method for three active components of Korean mint (Agastache rugosa (Fisch. & C.A.Mey.) Kuntze) extract in human plasma using ultra-high-performance liquid chromatography-tandem mass spectrometry

Agastache rugosa contains phenolic compounds and flavonoids, and has been extensively used as a traditional herbal medicine. The major components in Agastache rugosa extract (ARE) are rosmarinic acid, tilianin, and acacetin, for which several analytical techniques have been reported. However, these substances have yet to be simultaneously quantified in human plasma. In this study, we aimed to simultaneously determine the three active components of ARE in human plasma by developing a reliable quantitative analytical method using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Chromatographic separation of the plasma samples was achieved using an ACQUITY UPLC® BEH C18 column with a gradient mobile phase of water and acetonitrile containing 0.1 % formic acid. Mass spectrometric detection was performed using a triple quadrupole tandem mass spectrometer in negative electrospray ionization (ESI-) and multiple reaction monitoring (MRM) modes. The developed quantitative method was validated for the three active components. All three analytes exhibited a linear response over the ranges of 0.5-50 ng/mL for rosmarinic acid, 0.1-20 ng/mL for acacetin, and 0.5-20 ng/mL for tilianin with a weighting factor of 1/x (where x is the concentration). At three quality control (QC) concentration levels (low, medium, and high), including the lower limit of quantitation (LLOQ), acceptable accuracy (±15 %) was achieved in the intra- and interday validations. The concentration of rosmarinic acid was highest in plasma. Tilianin and acacetin appeared and were eliminated earlier in the plasma than rosmarinic acid. This study provides a successfully validated method that can be used in further clinical applications of Agastache rugosa extracts.

Identification and Characterization of Chemical Constituents in HuaTanJiangQi Capsules by UPLC-QTOF-MS Method

BACKGROUND

HuaTanJiangQi (HTJQ) is a classical Chinese medicine compound preparation, mainly used for clinically treating and improving chronic obstructive pulmonary disease (COPD) in China.

OBJECTIVE

To establish a rapid and efficient analytical method for the identification and characterization of chemical constituents in HTJQ based on ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS).

METHOD

UPLC-QTOF-MS was used to rapidly separate and identify the chemical constituents of HTJQ via a gradient elution system. The accurate mass data of the protonated and deprotonated molecules and fragment ions were detected in positive and negative ion modes. Compounds of HTJQ can be identified and assigned by analyzing accurate mass measurements and ion fragmentation mechanisms and comparing them with a chemical compositions database.

RESULTS

A total of 61 compounds in HTJQ were separated and identified, including 14 flavonoids, 16 organic acids, four isothiocyanic acids, eight butyl phthalides, two alkaloids, 10 terpenoids, four methoxyphenols and furanocoumarins, and three other compounds. The chemical compounds of HTJQ were identified and elucidated comprehensively for the first time.

CONCLUSIONS

A rapid, accurate, and efficient UPLC-QTOF-MS method has been developed for the identification of chemical components and applied to simultaneously evaluate the quality and effectiveness of HTJQ.

HIGHLIGHTS

Systematic identification of chemical constituents in HTJQ can provide a scientific and reasonable basis for the application of HTJQ in the clinical treatment of COPD.

An UPLC-MS/MS Method for Simultaneous Quantification of the Components of Shenyanyihao Oral Solution in Rat Plasma

Objectives

To study the quantification of the components in rat plasma after oral administration of Shenyanyihao oral solution.

Methods

Shenyanyihao oral solution has been traditionally used for the treatments of chronic nephritis in clinics. Stachydrine, Danshensu, chlorogenic acid, protocatechuic acid, plantamajoside, aesculetin, isoquercitrin, ferulic acid, baicalin, and baicalein are regarded as the main compounds in Shenyanyihao oral solution. A sensitive, efficient, and precise UPLC-MS/MS method was established and validated for the quantification of the components in rat plasma after oral administration of Shenyanyihao oral solution.

Results

The main pharmacokinetic parameters of the components were acquired based on the analysis of the plasma sample by a noncompartmental method using the WinNonlin7.0 pharmacokinetic program. Danshensu, protocatechuic acid, isoquercitrin, and ferulic acid from Shenyanyihao oral solution were quickly absorbed, and their peak concentration occurred at less than 0.5 h. The pharmacokinetic parameter of the average t_1/2 from Danshensu was 3.91 h in rats, and it was the most rapid distribution and elimination among the components. In addition, the C_max of stachydrine and baicalin were revealed as the higher plasma concentrations in rats.

Conclusions

This pharmacokinetic study seems to be useful for a further clinical study of Shenyanyihao oral solution in the treatments of chronic nephritis.

A HPLC-DAD-MS/MS Method for Simultaneous Determination of Six Active Ingredients of Salviae Miltiorrhizae and Ligustrazine Hydrochloride Injection in Rat Plasma and its Application to Pharmacokinetic Studies

AIMS

This is a pharmacokinetic study of Salviae miltiorrhizae and ligustrazine hydrochloride injection. The study aimed to evaluate the mechanism of action, safety and rational clinical use of Salviae miltiorrhizae and ligustrazine hydrochloride injection.

BACKGROUND

Salviae miltiorrhizae and ligustrazine hydrochloride injection is a compound preparation consisted of Salvia miltiorrhiza extract and ligustrazine hydrochloride for the treatment of cardiovascular and cerebrovascular diseases in China.

OBJECTIVE

The study aimed to develop a rapid and sensitive high-performance liquid chromatography-diode array detector-tandem mass spectrometry (HPLC-DAD-MS/MS) method for simultaneous determination of six major active ingredients of Salviae miltiorrhizae and ligustrazine hydrochloride injection, namely danshensu, protocatechuic aldehyde, rosmarinic acid, lithospermic acid, salvianolic acid A, and ligustrazine hydrochloride, in rat plasma.

METHODS

Plasma samples were precipitated with methanol, which was spiked with ascorbic acid and the supernatant was separated on a Waters Cortecs C18 column, by using a gradient mobile phase system of acetonitrile-water containing 0.05% formic acid (v/v). For internal standards, puerarin was selected for the five salvianolic acids, while isofraxidin was used for ligustrazine hydrochloride. Besides, electrospray ionization in negative mode and multiplereaction monitoring were used to identify and quantify the five salvianolic acids, whereas ligustrazine hydrochloride was quantified at 310 nm using the diode array detector.

RESULTS

Noticeably, all calibration curves showed good linearity (R2>0.99) over the concentration range, with a lower limit of quantification between 0.00411 and 0.0369 μg/mL for salvianolic acids, and 1.74 μg/mL for ligustrazine hydrochloride. Next, the precision of the developed method was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation was within 10%. Although the extraction efficiency of some salvianolic acids was not very satisfactory, the sensitivity of the analytical method met the analysis requirements of rat plasma samples. Moreover, the validated method was successfully applied to a pharmacokinetic study of Salviae miltiorrhizae and ligustrazine hydrochloride injection in the rat model.

CONCLUSION

Linear pharmacokinetic characteristics were observed for the six active ingredients after intravenous infusion administration in rats within the dose range examined here. In summary, our study proposed a HPLC-DADMS/ MS method with the simultaneous determination of multiple ingredients, and demonstrated its applicability in pharmacokinetic studies.

Involvement of Organic Anion Transporters in the Pharmacokinetics and Drug Interaction of Rosmarinic Acid

We investigated the involvement of drug transporters in the pharmacokinetics of rosmarinic acid in rats as well as the transporter-mediated drug interaction potential of rosmarinic acid in HEK293 cells overexpressing clinically important solute carrier transporters and also in rats. Intravenously injected rosmarinic acid showed bi-exponential decay and unchanged rosmarinic acid was mainly eliminated by urinary excretion, suggesting the involvement of transporters in its renal excretion. Rosmarinic acid showed organic anion transporter (OAT)1-mediated active transport with a K_m of 26.5 μM and a V_max of 69.0 pmol/min in HEK293 cells overexpressing OAT1, and the plasma concentrations of rosmarinic acid were increased by the co-injection of probenecid because of decreased renal excretion due to OAT1 inhibition. Rosmarinic acid inhibited the transport activities of OAT1, OAT3, organic anion transporting polypeptide (OATP)1B1, and OATP1B3 with IC₅₀ values of 60.6 μM, 1.52 μM, 74.8 μM, and 91.3 μM, respectively, and the inhibitory effect of rosmarinic acid on OAT3 transport activity caused an in vivo pharmacokinetic interaction with furosemide by inhibiting its renal excretion and by increasing its plasma concentration. In conclusion, OAT1 and OAT3 are the major transporters that may regulate the pharmacokinetic properties of rosmarinic acid and may cause herb-drug interactions with rosmarinic acid, although their clinical relevance awaits further evaluation.

Simultaneous Determination of 17 Constituents of Chinese Wild Radix Salvia miltiorrhiza from Different Geographical Areas by Ultra-High Performance Liquid Chromatography Coupled to Triple Quadrupole Mass Spectrometry

Background and Objective:

Radix Salvia miltiorrhiza (RSM) has been used clinically for the prevention and treatment of cardiovascular diseases; therefore, it is important to strengthen its quality management. Considering multiple constituents when assessing RSM quality is essential. We established a simple, rapid method to identify and quantify the major bioactive constituents in RSM using ultra high performance liquid chromatography (UPLC) coupled to a triple quadruple mass spectrometry (QqQ-MS).

Methods:

We analyzed 17 markers from 50 batches of wild S. miltiorrhiza samples that were collected from different locations in China. The ultrasonic extracts of all samples were determined using the UPLC-QqQ-MS method and were assessed by hierarchical cluster analysis (HCA).

Results:

We used this method to analyze 50 sample batches of the 17 compounds and obtained results with excellent linearity (R2, 0.9915-0.9997), precision (relative standard deviation, RSD, 0.15-1.94%), repeatability (RSD, 1.28-4.71%), stability (RSD, 0.97-5.60%) and recovery (RSD, 0.305-6.40%). The hierarchical cluster analysis was used to classify the 50 samples based on the characteristics of the 17 compound markers.

Conclusion:

We demonstrated that the developed method was simple, reproducible and sensitive, and it is capable of systematic and scientific evaluation for quality control of RSM. The HCA clearly demonstated that the RSM samples from different locations were significantly different and the quality of wild Radix S. miltiorrhiza could generally be judged according to its geographical origin.

Pharmacokinetics of 13 active components in a rat model of middle cerebral artery occlusion after intravenous injection of Radix Salviae miltiorrhizae-Lignum dalbergiae odoriferae prescription

As a representative formulation of Radix Salviae miltiorrhizae (Danshen)-Lignum Dalbergiae odoriferae (Jiangxiang), Xiangdan injection is widely prescribed for cardio- and cerebrovascular diseases in practice. This necessitates a pharmacokinetic investigation of this formulation to make it safer and more broadly applicable. We developed and validated a sensitive, selective, and reliable high-performance liquid chromatography with tandem mass spectrometry method for the simultaneous determination of 11 phenolic compounds including danshensu plus two diterpenoid quinones like cryptotanshinone and tanshinone IIA in rat. We applied this method for the pharmacokinetic studies of the 13 compounds in a rat model of middle cerebral artery occlusion after intravenous injection of Xiangdan injection or Danshen injection. In sham-operated rats, the animals taking Xiangdan injection exhibited significant growth of the area under the curve for danshensu, protocatechuic aldehyde, and tanshinone IIA compared with the changes seen in the data of those administrated with Danshen injection. Such a pattern was also observed in middle cerebral artery occlusion rats, whereas increased the area under the curve values were observed for danshensu, protocatechuic aldehyde, caffeic acid, rosmarinic acid, and tanshinone IIA. These results demonstrated that synergistic interactions occurred between the components of Danshen and the active compounds of Jiangxiang both in sham-operated and middle cerebral artery occlusion rats, increasing the bioavailability of Danshen. The results presented herein can be used to determine a reference dose for the clinical application of Xiangdan injection, and to elucidate the synergistic mechanism of Danshen and Jiangxiang.

Preclinical Absorption, Distribution, Metabolism, and Excretion of Sodium Danshensu, One of the Main Water-Soluble Ingredients in Salvia miltiorrhiza, in Rats

In this study, the absorption, distribution, metabolism and excretion (ADME) of sodium danshensu (Sodium DL-β-(3, 4-dihydroxyphenyl)lactate), one of the main water-soluble active constituents in Salvia miltiorrhiza, were evaluated in rats. Pharmacokinetic study was evaluated in doses of 15, 30, and 60 mg/kg after intravenous administration of sodium danshensu. Bioavailability study was evaluated by comparing between 30 mg/kg (I.V.) and 180 mg/kg (P.O.) of sodium danshensu. Tissue distribution, metabolism, and excretion were evaluated at 30 mg/kg (I.V.) of sodium danshensu. Following intravenous administration, sodium danshensu exhibited linear pharmacokinetics in the dose range of 15–60 mg/kg. Sodium danshensu appeared to be poorly absorbed after oral administration, with an absolute bioavailability of 13.72%. The primary distribution tissue was kidney, but it was also distributed to lung, stomach, muscle, uterus, heart, etc. Within 96 h after intravenous administration, 46.99% was excreted via urine and 1.16% was excreted via feces as the parent drug. Biliary excretion of sodium danshensu was about 0.83% for 24 h. Metabolites in urine were identified as methylation, sulfation, both methylation and sulfation, and acetylation of danshensu. Sodium danshensu can be developed as an injection because of its poor oral bioavailability. In conclusion, sodium danshensu is widely distributed, mainly phase II metabolized and excreted primarily in urine as an unchanged drug in rats.

Comparative pharmacokinetic study on phenolic acids and flavonoids in spinal cord injury rats plasma by UPLC-MS/MS after single and combined oral administration of danshen and huangqin extract

Chinese medicinal herbs danshen and huangqin have attracted attention in spinal cord injury (SCI) treatment. Purpose of this study was to investigate and compare the pharmacokinetic characteristics of 4 phenolic acids and 4 flavonoids in SCI rat plasma after orally administrate danshen, huangqin and combined extract of these two herbs (CDH). Thus, a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneously quantitative determination of tanshinol, protocatechualdehyde, protocatechuic acid, salvianolic acid A, baicalein, baicalin, wogonin and wogonoside. After inducing a contusion injury by a weight-drop device, SCI rats were orally administrated a single dose (12.5 g/kg) of danshen, huangqin and CDH extracts, respectively. Then, blood samples at different time points were collected and analyzed. In CDH group, C_max and AUC of tanshinol, protocatechualdehyde and protocatechuic acid significantly declined, while those of salvianolic acid A enhanced. These changes were beneficial for danshen to treat SCI. As for flavonoids, double peaks were observed in huangqin group, while this phenomenon disappeared in CDH group. Concomitantly, C_max and AUC declined after administrated CDH. These alterations were due to influence of danshen active constituents on absorption and transportation process of flavonoids. Therefore, danshen and huangqin significantly influenced pharmacokinetic profile and parameters of each other, thus exert synergistic therapeutic effect in SCI treatment.

A UPLC-MS/MS Method for Simultaneous Determination of Six Bioactive Compounds in Rat Plasma, and its Application to Pharmacokinetic Studies of Naoshuantong Granule in Rats

Background:

It is urgently needed to clarify the pharmacokinetic mechanism for the multibioactive constituents in Traditional Chinese Medicines for its clinical applications. A rapid, sensitive and reliable ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of Danshensu, Ferulic acid, Astragaloside IV, Naringin, Neohesperidin and Puerarin after oral administration of Naoshuantong Granule using Carbamazepine as internal standard (IS).

Methods:

The plasma samples were pretreated by liquid-liquid extraction method using ethyl acetate after acidification, and separated on a Waters ACQUITY UPLC® BEH C18 column (50×2.1 mm, i.d., 1.7 µm) by gradient elution with a mobile phase composing of water (containing 0.1% formic acid) and acetonitrile at a flow rate of 0.2 mL/min. Multiple reaction monitoring (MRM) mode with both positive and negative ion mode was operated using an electrospray ionization (ESI) to detect the six compounds.

Result:

All calibration curves showed good linearity (r>0.99) over a wide concentration range. The intra- and inter-day precision (RSD%) was below 8.4% and the accuracy (RE%) ranged from 91.1% to 107.5%. The extraction recoveries of the six analytes and IS in the plasma were more than 77.9% and no severe matrix effect was observed.

Conclusion:

The fully validated method was successfully applied to the pharmacokinetics of Naoshuantong Granule.

Pharmacokinetic behaviors of ligustrazine after single- and multiple-dose intravenous Shenxiong glucose injection in rats by high-performance liquid chromatography

Shenxiong glucose injection (SXG) is a traditional Chinese medicine that is used for cardio-cerebral vascular diseases on the national essential drug list of China. To date, a comprehensive knowledge concerning the pharmacokinetic profile of SXG-related components, especially following multiple dosing, is still lacking. This study was designed to investigate the pharmacokinetics and tissue distribution of ligustrazine after single- and multiple-dose intravenous administration of SXG in rats. A simple HPLC method was developed for the determination of ligustrazine in biological samples. The pharmacokinetic profiles of ligustrazine in rats were linear after both single- and multiple-dose intravenous administration of SXG, with a half-life of approximately 35 min. Ligustrazine was readily distributed in highly perfused organs and almost eliminated from organs after 90 min of SXG injection. The AUC_0-t and C₀ of ligustrazine after SXG injection (18 ml/kg, equal to 9.0 mg/kg ligustrazine) were increased significantly compared to those of single ligustrazine administration (9.0 mg/kg), indicating that the pharmacokinetics of ligustrazine in the SXG were affected by other ingredients. This study provided first evidence for the pharmacokinetic characteristics of ligustrazine after both single and multiple-dose SXG in rats, which would be helpful for its clinical application.

Recent Patents Concerning the use of Nanotechnology-based Delivery Systems as Skin Penetration Enhancers

Nanotechnology-based delivery systems have been considered a promising approach for topical application, considering their characteristics of penetration into/across the skin. The present review aimed to evaluate the recent international scenario of patents concerning the use of nanotechnology- based delivery systems as skin penetration enhancers. A survey of recent patent documents was conducted by using the Espacenet patent database including the terms "skin" in the title and "promot* or enhanc* and penetrat* or absorp* or permeat*" and "nano*" with the truncation symbol (*) in the abstract of documents. A total of 110 patents were published from 2008 to 2018, with 94 technologies being considered. The results demonstrated an increase in innovations concerning nanotechnologybased delivery systems as skin penetration enhancers in recent years. Most patent applicants are from China (60.6%) and Korea (21.3%), and companies (68%) were the most prominent owners. The majority of patent applications (76%) were intended for cosmetic purposes; the types of products and nanostructures were also investigated. Overall results demonstrated the increased interest around the world in patenting products involving skin permeation promotion and nanotechnology for pharmaceutical and, mainly, for cosmetics purposes.

A sensitive LC-MS/MS-based bioanalytical method for quantification of salviaflaside and rosmarinic acid in rat plasma and its application in a pharmacokinetic study

A selective and sensitive liquid chromatography tandem mass spectrometry method was developed for the simultaneous determination of salviaflaside and rosmarinic acid in rat plasma. Sample preparation was carried out through liquid-liquid extraction with ethyl acetate using curculigoside as internal standard (IS). The analytes were determined by selected reaction monitoring operated in the positive ESI mode. Chromatographic separation was performed on an Agilent Eclipse Plus C18 column (100 × 4.6 mm, 1.8 μm) with a mobile phase consisting of methanol-water-formic acid (50:50:0.1, v/v/v) at a flow rate of 0.3 mL/min. The run time was 1.9 min per sample and the injection volume was 5 μL. The method had an LLOQ of 1.6 ng/mL for salviaflaside and 0.94 ng/mL for rosmarinic acid in plasma. The linear calibration curves were fitted over the range of 1.6-320 ng/mL for salviaflaside and 0.94-188 ng/mL for rosmarinic acid in plasma with correlation coefficients (r2 ) >0.99. Intra- and inter-day precisions (relative standard deviation) were < 13.5%, and accuracies (relative error) were between -8.6% and 14.5% for all quality control samples. The method was validated and applied to the pharmacokinetics of salviaflaside and rosmarinic acid in plasma after oral administration of Prunella vulgaris extract to rats.

A novel, simplified and stability-indicating high-throughput ultra-fast liquid chromatography method for the determination of rosmarinic acid in nanoemulsions, porcine skin and nasal mucosa

Currently, there is an increasing interest on the development of topical formulations containing rosmarinic acid (RA) due to its well-documented antioxidant activity. This study aimed to develop and validate a stability-indicating ultra-fast liquid chromatography (UFLC) method for the determination of RA in nanoemulsions, porcine skin and nasal mucosa intended to be applied in permeation/retention studies and for development of topical nanoemulsions. Chromatographic separation was carried out using a C18 column packed with 2.6 μm particle size in isocratic conditions using as mobile phase water:acetonitrile (83:17, v/v), acidified with 0.1% trifluoracetic acid (v/v), with a total time of analysis of 3.5 min and detection at 330 nm. RA analysis was specific in the presence of both non-biological (blank nanoemulsion and receptor fluid) and biological matrices (porcine ear skin and porcine nasal mucosa). No interference of degradation products of RA was verified after different stress conditions such as acidic, alkaline, oxidative, light exposure (UV-A and UV-C) and thermal demonstrating the method stability-indicating property. The analytical (0.1-10.0 μg·mL-1) and bioanalytical (0.5-10.0 μg·mL-1) linearity was proved by analysis of the calibration curves of RA and no matrix effect was observed. The method was sensitive, precise and accurate, and showed recovery higher than 85%. The method was considered robust as evaluated by a Plackett-Burman experimental design. In the validated conditions, the RA was determined in the nanoemulsions obtained by spontaneous emulsification procedure (1.007 ± 0.040 mg·mL-1), porcine ear skin (1.13 ± 0.19 μg·cm-2) and nasal mucosa (22.46 ± 3.99 μg·cm-2) after retention/permeation studies. Thus, a highly sensitive, simple, fast and stability-indicating method was developed for RA analysis during the development of topical nanoemulsions and bioanalytical assays in complex matrices.

Screening and analysis of potentially active components in Shenxiong glucose injection using UHPLC coupled with photodiode array detection and MS/MS

Shenxiong glucose injection, a pharmaceutical preparation containing a water extract of the roots of Salvia miltiorrhizae and ligustrazine hydrochloride, is widely used in clinical to treat cardiovascular diseases in China. The chemical components of the water extract have been reported and the cardioprotective effects of the injection have been evaluated. However, the chemical constituents of the injection and their correlations with its pharmacological effects have not been established. In this study, 13 chemical constituents of the injection have been identified or characterized by ultra-high performance liquid chromatography with diode array detection and electrospray ionization quadrupole time-of-flight tandem mass spectrometry. Besides, the potentially active compounds of this preparation that directly act on cardiac cells have been screened by cell extraction and ultra high performance liquid chromatography targeted multiple reaction monitoring. As a result, eight potentially active compounds, danshensu (1), ligustrazine hydrochloride (4), salvianolic acid I/H (7), lithospermic acid (8), salvianolic acid D (9), rosmarinic acid (10), salvianolic acid B (12), and salvianolic acid C (13), were obtained and structurally characterized from the 11 target compounds used for screening. The liquid chromatography with quadrupole time-of-flight mass spectrometry and liquid chromatography with multiple reaction monitoring tandem mass spectrometry combination method has demonstrated its potency for the screening, detection, and structural identification of bioactive compounds in a complex matrix.

Enhancement of brain-targeting delivery of danshensu in rat through conjugation with pyrazine moiety to form danshensu-pyrazine ester

Tetramethylpyrazine was introduced to the structure of danshensu (DSS) as P-glycoprotein (P-gp)-inhibiting carrier, designing some novel brain-targeting DSS-pyrazine derivatives via prodrug delivery strategy. Following the virtual screening, three DSS-pyrazine esters (DT1, DT2, DT3) were selected because of their better prediction parameters related to brain-targeting. Among them, DT3 was thought to be a promising candidate due to its appropriate bioreversible property in vitro release assay. Further investigation with regard to DT3's brain-targeting effects in vivo was also reported in this study. High-performance liquid chromatography-diode array detection (HPLC-DAD) method was established for the quantitative determination of DT3 and DSS in rat plasma, brain homogenate after intravenous injection. In vivo metabolism of DT3 indicated that it was first converted into DT1, DT2, then the generation of DSS, which could be the result of carboxylesterase activity in rat blood and brain tissue. Moreover, the brain pharmacokinetics of DT3 was significantly altered with 2.16 times increase in half-life compared with that of DSS, and its drug targeting index (DTI) was up to 16.95. Above these data demonstrated that DT3 had better tendency of brain-targeting delivery, which would be positive for the treatment of brain-related disorders.

Pharmacokinetic Analysis of Four Bioactive Iridoid and Secoiridoid Glycoside Components of Radix Gentianae Macrophyllae and Their Synergistic Excretion by HPLC-DAD Combined with Second-Order Calibration

An HPLC-DAD method combined with second-order calibration based on the alternating trilinear decomposition (ATLD) algorithm with the aid of region selection was developed to simultaneously and quantitatively characterize the synergistic relationships and cumulative excretion of the four bioactive ingredients of Radix Gentianae Macrophyllae in vivo. Although the analytes spectra substantially overlapped with that of the biological matrix, the overlapping profiles between analytes and co-eluting interferences can be successfully separated and accurately quantified by the ATLD method on the basis of the strength of region selection. The proposed approach not only determined the content change but also revealed the synergistic relationships and the cumulative excretion in vivo of the four ingredients in urine and feces samples collected at different excretion time intervals. In addition, several statistical parameters were employed to evaluate the accuracy and precision of the method. Quantitative results were confirmed by HPLC-mass spectrometry. Satisfactory results indicated that the proposed approach can be utilized to investigate the pharmacokinetics of Radix Gentianae Macrophyllae excretion in vivo.

Simultaneous determination of eight bioactive components of Qishen Yiqi dripping pills in rat plasma using UFLC-MS/MS and its application to a pharmacokinetic study

In this study, a rapid and reliable ultra-fast liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of eight active ingredients, including astragaloside IV, ononin, tanshinol, protocatechualdehyde, protocatechuic acid, salvianolic acid D, rosmarinic acid and ginsenoside Rg1 , in rat plasma. The plasma samples were pretreated by protein precipitation with acetonitrile. Chromatographic separation was performed on a Waters Acquity UPLC® BEH C18 column (1.7 μm particles, 2.1 × 100 mm). The mobile phase consisted of 0.1% aqueous formic acid (A)-acetonitrile with 0.1% formic acid (B) at a flow rate of 0.4 mL/min. Quantification was performed on a triple quadruple tandem mass spectrometry with electrospray ionization by multiple reaction monitoring both in the negative and in the positive ion mode. The lower limit of quantification of tanshinol was 2.0 ng/mL and the others were 5.0 ng/mL. The extraction recoveries, matrix effects, intra- and inter-day precision and accuracy of eight tested components were all within acceptable limits. The validated method was successfully applied to the pharmacokinetic study of the eight active constituents after intragastric administration of three doses (1.0, 3.0, 6.0 g/kg body weight) of Qishen Yiqi Dripping Pills to rats.

Simultaneous determination of three active components in rat plasma by UPLC-MS/MS: Application to pharmacokinetic study after oral administration of Herba Sarcandrae extract

A rapid, specific and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of isofraxidin, rosmarinic acid and kaempferol-3-O-glucuronide in rat plasma using warfarin as an internal standard (IS). Separation was conducted on a Thermo Hypersil GOLD C18 column with linear gradient elution using methanol and water. Mass spectrometric detection was conducted using selected reaction monitoring (SRM) via an electrospray ionization (ESI) source. All analytes exhibited good linearity within their concentration ranges (r > 0.9990). The lower limits of quantitations of isofraxidin, rosmarinic acid, and kaempferol-3-O-glucuronide were 1.31, 0.67 and 0.92 ng/mL, respectively. Intra- and inter-day precisions of these investigated components exhibited an RSD within 11.7%, and the accuracy ranged from -12.5 to 15.0% at all QC levels. The developed method was successfully applied to a pharmacokinetic study of isofraxidin, rosmarinic acid, and kaempferol-3-O-glucuronide in rats after oral administration of Herba Sarcandrae Extract.

Chemical Analysis of the Herbal Medicine Salviae miltiorrhizae Radix et Rhizoma (Danshen)

Radix Salviae miltiorrhizae et Rhizoma, known as Danshen in China, is one of the most popular traditional Chinese medicines. Recently, there has been increasing scientific attention on Danshen for its remarkable bioactivities, such as promoting blood circulation, removing blood stasis, and clearing away heat. This review summarized the advances in chemical analysis of Danshen and its preparations since 2009. Representative established methods were reviewed, including spectroscopy, thin layer chromatography, gas chromatography, liquid chromatography (LC), liquid chromatography-mass spectrometry (LC-MS), capillary electrophoresis, electrochemistry, and bioanalysis. Especially the analysis of polysaccharides in Danshen was discussed for the first time. Some proposals were also put forward to benefit quality control of Danshen.