Comparative pharmacokinetic study of two boswellic acids in normal and arthritic rat plasma after oral administration of Boswellia serrata extract or Huo Luo Xiao Ling Dan by LC‐MS

Huo Luo Xiao Ling Dan (HLXLD), a Chinese herbal formula composed of 11 different herbs, has been used traditionally for the treatment of arthritis and other chronic inflammatory diseases. However, the pharmacokinetic profile of its anti‐inflammatory bioactive compounds has not been elucidated. Boswellic acids are the bioactive compounds with potent anti‐inflammatory activity isolated from Boswellia serrate which is one of the 11 herbs of HLXLD. The objective of the study was to compare the pharmacokinetics of the two bioactive bowsellic acids: 11‐keto‐β‐boswellic acid and 3‐O‐acetyl‐11‐keto‐β‐boswellic following oral administration of HLXLD or Boswellia serrata extract alone in normal and arthritic rats. An LC‐MS method was developed and validated for the determination of 11‐keto‐β‐boswellic acid and 3‐O‐acetyl‐11‐keto‐β‐boswellic in the comparative pharmacokinetic study. The results showed that there were significant differences in pharmacokinetic parameters between normal and arthritic groups. Interestingly, the absorptions of two boswellic acids were significantly higher in HLXLD than Boswellia serrata extract alone, indicating the synergistic effect of other herbal ingredients in HLXLD. This comparative pharmacokinetic study provided direct evidence supporting the notion that the efficacy of a complex mixture such as HLXLD is better than that of single components in treating human diseases. Copyright © 2014 John Wiley & Sons, Ltd.     

Comparative pharmacokinetics of nine major bioactive components in normal and ulcerative colitis rats after oral administration of Lizhong decoction extracts by UPLC–TQ–MS/MS

Lizhong decoction (LZD), a classic formula, has been used to treat ulcerative colitis (UC) for thousands of years in clinical practice. However, the pharmacokinetic characteristics of its major bioactive components in rats under different physiological and pathological states are not clear. Thus, in this study, a rapid and sensitive analytical method, ultra‐performance liquid chromatography coupled with mass spectrometry (UPLC–MS/MS) method, was developed and applied to simultaneously determine glycyrrhizic acid, liquiritin, isoliquiritin, glycyrrhizin, isoliquiritigenin, 6‐gingerol, ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Re in normal and UC rats after oral administration of LZD extract. A Waters BEH C₁₈ UPLC column was used for chromatographic separation, while acetonitrile and 0.1% formic acid were selected as mobile phase. The linearity of nine analytes was >0.9920. Inter‐ and intra‐day accuracy was ≤ 11.4% and precision was from 1.1 to 12.7%. Additionally, stable and suitable extraction recoveries were also obtained. The established method was validated and found to be specific, accurate and precise for nine analytes. Furthermore, it was successfully applied to the pharmacokinetic investigation of nine major components after oral administration of LZD extracts to normal and model rats, respectively. The results showed that the pharmacokinetic parameters (C_max, T_max, AUC_0–t, AUC_0–∞) in the plasma of UC rats were significantly different from those of normal rats, which could provide a reference for the clinical application of LZD.     

A UFLC–MS/MS method for the simultaneous determination of eight bioactive constituents from red wine and dealcoholized red wine in rat plasma: Application to a comparative pharmacokinetic study

To explore whether alcohol has an effect on the pharmacokinetic behavior of phenolic acids, the main bioactive constituents in red wine, a highly sensitive and simple ultra‐fast liquid chromatography coupled with triple quadrupole mass spectrometry (UFLC–MS/MS) method was developed for simultaneous quantitation of eight phenolic acids in plasma samples. Plasma samples were extracted by liquid–liquid extraction and the chromatographic separation was achieved on a Zorbax SB‐C₁₈ column within 7.0 min. Results of the validated method revealed that all of the calibration curves displayed good linear regression (r > 0.99). The intra‐ and inter‐day precisions of the analytes were <14.0% and accuracies ranged from ?8.5 to 7.3%. The extraction recoveries of the analytes were from 71.2 to 110.2% and the matrix effects ranged from 86.2 to 105.5%. The stability of these compounds under various conditions satisfied the requirements of biological sample measurement. The method was successfully applied to a comparative pharmacokinetic study of phenolic acids in rat plasma. For gallic acid and gentisic acid, the parameters AUC_0–t and AUC_0–∞ increased remarkably (p < 0.05) after oral administration of red wine, which suggested that alcohol might enhance their absorption. This is the first report to compare the pharmacokinetic behavior of phenolic acids in red wine and dealcoholized red wine.     

Comparative pharmacokinetics study of leonurine and stachydrine in normal rats and rats with cold‐stagnation and blood‐stasis primary dysmenorrhoea after the administration of Leonurus japonicus houtt electuary

Leonurus japonicus houtt, a well‐known herb of traditional Chinese medicine, is widely used to treat gynaecological diseases. In this study, a rapid and sensitive liquid chromatography with tandem mass spectrometry method for simultaneously quantifying leonurine and stachydrine, the two main bioactive components in Leonurus japonicus houtt, was developed and validated. Plasma samples were prepared by protein precipitation with acetonitrile and separation by a Hewlett Packard XDB‐C8 column (150 × 4.6 mm, id, 5 μm) equipped with a gradient elution system containing methanol‐water and 0.1% formic acid at a flow‐rate of 0.4 mL/min. Components were then detected by a mass spectrometer in positive electrospray ionization mode. This method showed good linearity, precision, accuracy, recovery, stability, and negligible matrix effects, which were within acceptable ranges. The method was successfully applied to compare the pharmacokinetics in normal rats and rats with cold‐stagnation and blood‐stasis primary dysmenorrhoea treated with Leonurus japonicus houtt electuary. The result showed significant differences (p < 0.05) in the pharmacokinetic parameters between the primary dysmenorrhoea and normal groups. This result implied that Leonurus japonicus houtt electuary remained longer and was absorbed slower in rats with primary dysmenorrhoea and exhibited higher bioavailability and peak concentration.     

Comparative pharmacokinetic study of the main components of cortex fraxini after oral administration in normal and hyperuricemic rats

Cortex Fraxini is an important traditional Chinese herbal medicine used for the treatment of gout and hyperuricemia. An efficient and rapid ultra‐performance liquid chromatography mass spectrometry method was developed and validated for simultaneous quantitation of six coumarins (aesculin, fraxin, aesculetin, fraxetin, sopoletin and 7‐hydroxycoumarin) in normal and hyperuricemic rats plasma after oral administration of Cortex Fraxini. The method could successfully be applied for pharmacokinetics studies. The pharmacokinetic behavior of six coumarins in normal and hyperuricemia rats plasma was determined. Results showed that, for some of analytes, the pharmacokinetic parameters (AUC_0–t , AUC_0–∞, C _max, T _max and CL ) were significantly different between normal and hyperuricemic rats. The different pharmacokinetic parameters might result from renal impairment or a change of metabolic enzymes in the pathological state. The pharmacokinetic study in pathological state could provide more useful information to guide the clinical use of traditional Chinese herbal medicine.     

Comparative pharmacokinetic study of pyranocoumarins and khellactone in normal and acute lung injury rats after oral administration of Peucedanum praeruptorum Dunn extracts using a rapid and sensitive liquid chromatography–tandem mass spectrometry method

Pyranocoumarins are the main constitutes in Peucedanum praeruptorum Dunn and possess various biological activities. In this article, we developed and validated a rapid and sensitive liquid chromatography–tandem mass spectrometry method for the targeted quantification of the pyranocoumarins, praeruptorin A, praeruptorin B and praeruptorin E, and khellactone, which is a common metabolite of these pyranocoumarins in rat plasma samples. We then performed a comparative pharmacokinetic study of these pyranocoumarins and khellactone in normal and lipopolysaccharide‐induced acute lung injury (ALI) in rats following oral administration of P. praeruptorum Dunn extracts. Calibration curves gave desirable linearity (r > 0.99) and the lower limit of quantifications were sufficient for quantitative analysis. The precision and accuracy were assessed by intra‐batch and inter‐batch assays, and the relative standard deviations were all within 10.23% and the accuracy (relative error) was between −5.52% and 8.68%. The extraction recoveries, matrix effects and stability were also acceptable. The pharmacokinetic study revealed that the area under the concentration–time curve (0–t ) of khellactone in ALI rats was significantly decreased compared with the normal rats. Meanwhile, the systemic exposures of these pyranocoumarins were slightly higher in the ALI rats than those in normal rats were. The pharmacokinetic study in the pathological state might provide information that was more comprehensive to guide the clinical usage of P. praeruptorum Dunn.      

Effects of Tao‐Hong‐Si‐Wu decoction on acute blood stasis in rats based on a LC‐Q/TOF‐MS metabolomics and network approach

A novel approach using metabolomics coupled with a metabolic network was used to investigate the effects of Tao‐Hong‐Si‐Wu decoction (THSWD) on the rat model of acute blood stasis syndrome. Acute blood stasis syndrome was induced by placing the rats in ice‐cold water following two injections with epinephrine. The hemorheological indicators [whole blood viscosity (WBV) and plasma viscosity (PV)] and the blood coagulation indicators [thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB)] were detected. The nonparametric univariate method and multivariate statistical analysis were performed for determining the potential biomarkers. A correlation map was structured between biochemical indicators and hub metabolites to explain the effects mechanism of THSWD. After the administration of THSWD, the levels of WBV, PV, TT, APTT and FIB returned to levels observed in the control group. According to metabolomics coupled with metabolic network analysis, the intervention of THSWD in rats with acute blood stasis syndrome induced substantial and characteristic changes in their metabolic profiles. Fifteen metabolites were screened, which mainly involved 10 pathways and five hub metabolites, namely, l ‐glutamate, l ‐phenylalanine, N‐acylsphingosine, arachidonic acid and phosphatidate. The biochemical indicators and hub metabolites could be adjusted to close to normal levels by THSWD. Therefore, combining metabolomics and metabolic network helped to evaluate the effects of THSWD on acute blood stasis.     

Simultaneous determination of five triterpene acids in rat plasma by liquid chromatography–mass spectrometry and its application in pharmacokinetic study after oral administration of Folium Eriobotryae effective fraction

Folium Eriobotryae effective fraction (FEA), the extract of Folium Eriobotryae, had been used as anti‐hyperglycemia and anti‐hyperlipemia medicine in China. A previous study indicated that euscaphic acid, maslinic acid, corosolic acid, oleanolic acid and ursolic acid, the five structurally similar triterpene acids (containing two groups of structural isomers), are the major components of FEA. In the present study, we developed a specific and reliable LC‐MS method for simultaneous determination of the five triterpene acids in rat plasma, and further investigated their pharmacokinetic properties after oral administration of FEA. Following a simple sample preparation, chromatographic separation was achieved on a C₁₈ column with a mobile phase composed of methanol–0.1% ammonium acetate (80:20, v/v). Quantification was achieved by monitoring the selected ions at m/z 487.6 for euscaphic acid, m/z 471.5 for maslinic acid and corosolic acid, m/z 455.5 for oleanolic acid and ursolic acid and m/z 469.5 for internal standard. The method was validated to be specific, accurate and precise over the concentration ranges of 10–3000 ng/mL with limits of detections of 5 ng/mL for the five triterpene acids. Finally, the method was successfully applied to the pharmacokinetic study of the five structurally similar triterpene acids in rats after oral administration of FEA. Copyright © 2015 John Wiley & Sons, Ltd.     

Comparative pharmacokinetic studies of Ephedra herba in common cold and nephrotic syndrome rat models

Ephedra herba is a conventional Chinese medicine to treat cold, fever, asthma, edema, and lung diseases in the clinic. At present, most pharmacokinetic studies focus on the pharmacokinetic process of alkaloids in normal animals. However, the non-alkaloid components are also active. In addition, the pharmacokinetic studies under pathological state make more sense for clarifying the material basis of efficacy. In this study, a sensitive and rapid ultra-high-performance–tandem mass spectrometry method was developed and applied to determine nine bioactive components (ephedrine, pseudoephedrine, methylephedrine, (+)-catechin, epicatechin, vitexin, vicenin-2, cinnamic acid, and ferulic acid) in normal, common cold and nephrotic syndrome rats after the oral administration of Ephedra herba. Compared to the normal group, except for ferulic acid, the exposure levels of the other eight components were significantly increased and the plasma clearance clearly declined in common cold rats. Similarly, the exposure levels of seven components other than cinnamic acid and ferulic acid were also significantly augmented and the plasma clearance decreased significantly in nephrotic syndrome rats. In brief, the pathological conditions of the common cold and nephrotic syndrome could lead to alterations in the pharmacokinetics profiles of the nine components, which provide a reference for further exploration of the pharmacodynamics basis of Ephedra herba.     

Simultaneous quantification of anthraquinone glycosides,aglycones, and glucuronic acid metabolites in rat plasma and tissues after oral administration of raw and steamed rhubarb in blood stasis rats by UHPLC-MS/MS

Rhubarb is a widely used herbal medicine. To achieve different effects, rhubarb is usually steamed with rice wine (steamed rhubarb). This steaming treatment increases the blood-activating and stasis-removing effects of rhubarb. A specific and accurate ultra high performance liquid chromatography with tandem mass spectrometry method was established for simultaneous determination of anthraquinone glycosides, aglycones, and glucuronic acid metabolites in plasma and tissues after administration of raw rhubarb and steamed rhubarb in blood stasis rats. Chromatographic separation was performed on ACQUITY UPLC BEH Shield RP 18 column using the mobile phase consisting of water and acetonitrile both containing 0.1% formic acid. Satisfactory linearity, precision, accuracy, extraction recovery, and matrix effect have been achieved. From pharmacokinetic study, it showed that glucuronic acid metabolites were found abundantly in plasma as bioactive components. The lower area under concentration-time curve, maximum concentration, and higher apparent volume of distribution (P < 0.01), body clearance (P < 0.01) values in steamed rhubarb showed that most components of steamed rhubarb have lower bioavailability in plasma compared with raw rhubarb. But it found these components were mainly distributed in spleen and liver with large blood flow and perfusion rates. The pharmacokinetics and tissue distribution studies of anthraquinone components will provide helpful information for clinical application of steamed rhubarb and raw rhubarb.     

Ultra‐high performance liquid chromatography with tandem mass spectrometry method for the simultaneous quantitation of five phthalides in rat plasma: Application to a comparative pharmacokinetic study of Huo Luo Xiao Ling Dan and herb‐pair extract

A fast, sensitive, and reliable ultra‐high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the simultaneous quantitation and pharmacokinetic study of five phthalides (senkyunolide A, ligustilide, butylidenephthalide, 3‐butylphthalide, and levistilide A) in rat plasma after oral administration of Huo Luo Xiao Ling Dan (HLXLD) or Angelica sinensis‐‐Ligusticum chuanxiong herb pair (DG‐CX) between normal and arthritis rats. After extraction from blood, the analytes and internal standard were subjected to ultra‐high performance liquid chromatography with a Shim‐pack XR‐ODS column (75 × 3.0 mm², 2.2 μm particles) and mobile phase was composed of methanol and water (containing 0.05% formic acid) under gradient elution conditions, with an electrospray ionization source in the positive ionization and multiple reaction monitoring mode. The lower limits of quantification were 0.192–0.800 ng/mL for all the analytes. Satisfactory linearity, precision, accuracy, mean extraction recovery, and acceptable matrix effect have been achieved. The validated method was successfully applied to a comparative pharmacokinetic study of five bioactive components in rat plasma after oral administration of HLXLD or DG‐CX alone, respectively, between normal and arthritic rats. The results showed that there were unlike characters of pharmacokinetics among different groups.     

Metabolic characteristics and pharmacokinetic differences of Qiwei Tongbi oral liquid in rheumatoid arthritis rats

Qiwei Tongbi oral liquid (QWTB), a classical traditional Chinese medicine formula, is widely used to treat arthritis-related diseases in clinical practice. Currently, in vivo metabolic characteristics and pharmacokinetic studies are lacking. This study analyzed the prototype components of QWTB absorbed in the blood and their metabolic transformation process after intragastric administration and compared the differences in pharmacokinetic properties between healthy and rheumatoid arthritis model rats. In sum, 17 prototype components and 21 related metabolites were identified in the plasma and urine of the treated rats. Metabolites were derived from sinomenine and magnoflorine. Through systematic methodology verification, an accurate and stable detection method for sinomenine and magnoflorine in plasma samples was established and applied to pharmacokinetic research of QWTB. At the three dose levels, the AUC_0–∞ (area under the curve) of the two components showed a good positive correlation with the dose (R² > 0.9). Compared with healthy rats, the T_max, t_1/2z, and AUC of sinomenine were markedly increased, and C_max was decreased in rheumatoid arthritis model rats, indicating that the rate of absorption and elimination rate decreased, but the body exposure increased. However, there were no significant differences in the pharmacokinetic parameters of magnoflorine under healthy and pathological conditions. In summary, the main active ingredients of QWTB are sinomenine and magnoflorine, which exhibit linear kinetic characteristics within a set dose range, and the rheumatoid arthritis pathological state is more conducive to the absorption and efficacy of sinomenine. The results of this study demonstrate the rationality of the clinical application of the QWTB.     

Simultaneous determination of five isoflavones in rat plasma by LC‐MS/MS: Comparative pharmacokinetic characteristics of Puerariae lobatae radix in normal and type 2 diabetic rats

A rapid and sensitive liquid chromatography with tandem mass spectrometry method was developed and validated for simultaneous determination of puerarin, daidzin, daidzein, 3′‐hydroxy puerarin, and genistein in rat plasma after oral administration of Puerariae lobatae radix extract. The method of protein precipitation with acetonitrile was used for sample preparation. Chromatographic separation was achieved on a C₁₈ column with the mobile phases of acetonitrile/water containing 0.1% formic acid. The analytes were detected by mass spectrometer with an electrospray ionization source operating in the negative ion mode. The linearity, precision, accuracy, dilution reliability, recovery, matrix effects, and stability of the method were within acceptable ranges. The developed method was successfully used to compare the pharmacokinetic characteristics of five analytes in normal and type 2 diabetics rats after oral administration of Puerariae lobatae radix extract. Several pharmacokinetic alterations were observed and this might be caused by the pathological state of type 2 diabetes.     

A simple and selective UHPLC–MS/MS method for quantification of plantagoguanidinic acid in rat plasma and its application to a pharmacokinetic study

A simple, sensitive and specific UHPLC–MS/MS method for quantification of plantagoguanidinic acid (PGA) in rat plasma was applied to investigate the pharmacokinetic behavior in vivo , using protopine as internal standard. The chromatography was separated on a Phenomenex® Luna‐C₁₈ column (2.1 × 150 mm, 3.0 μm) within 7.0 min using a mobile phase consisting of acetonitrile–0.1% formic acid solution under gradient elution at a flow rate of 0.4 mL/min. Prepared samples were monitored by multiple reaction monitoring mode, with the target fragmentions m/z 226.2 → 84.2 for PGA and m/z 354.2 → 188.9 for IS in positive electrospray ionization. The calibration curve of PGA was linear throughout the range 1–1000 ng/mL (r = 0.9962). The lower limit of quantitation in plasma for PGA was 0.1 ng/mL, and the recovery was >88.6%. Intra‐ and interday accuracy ranged from −8.6 to 4.9%. Furthermore, this validated method was successfully used for a pre‐clinical pharmacokinetic study of PGA at a single dose of 20 and 5 mg/kg in rats via oral and intravenous administration. The study showed that PGA was absorpted rapidly and eliminated gradually with a greater absolute oral bioavailability of 70.1% in rats.     

Monopalmityloxy Shikimic Acid: Enzymatic Synthesis and Anticoagulation Activity Evaluation

The monopalmityloxy shikimic acids have been synthesized from shikimic acid and palmitic acid catalyzed by Novozym 435 in 2-methyl-2-butanol. The anticoagulation activity in vivo via oral administration of monopalmityloxy shikimic acid has been evaluated through arteriovenous shunt model of rats and through the determination of thrombin time, prothrombin time, and activated partial thromboplastin time via rats. After reaction, the solid shikimic acid has been observed to dissolve in the reaction system completely. The subsequent high-performance liquid chromatography–mass spectroscopy analysis showed that the monopalmityloxy shikimic acids, as the only products, had been formed and the overall conversion rate was over 70%. The result showed that it had anti-thrombosis activity, could prolong the coagulating time and bleeding time in vivo, and lengthen the coagulating time in vitro. Compared with control group, the differences of the treatment group and aspirin group of rats are significant (P < 0.05) for prothrombin time and thrombin time, and very significant (P < 0.01) for activated partial thromboplastin time. It suggested that the product had the anticoagulation activity. The mechanism might be the co-action of the inhibition of intrinsic coagulation and the inhibition of extrinsic coagulation, and the inhibiting effect on intrinsic pathway is stronger than that on extrinsic pathway.     

A liquid chromatography–tandem mass spectrometry method for preclinical pharmacokinetics and tissue distribution of hydrolyzable tannins chebulinic acid and chebulagic acid in rats

A simple and sensitive liquid chromatography–tandem mass spectrometry method was developed for the simultaneous determination of chebulinic acid and chebulagic acid in rat plasma and tissues and well used in the pharmacokinetic and tissue distribution studies after intraperitoneal injection administration. Samples were processed with methanol by protein precipitation, and chromatographic separation was performed on an Agilent Zorbax SB‐C₁₈ column (50 × 2.1 mm, 1.8 μm) with a mobile phase consisting of methanol and water containing 0.1% formic acid (60:40, v/v). Quantification was performed by selected reaction monitoring with m/z 977.1 → 806.8 for chebulagic acid, m/z 979.0 → 808.7 for chebulinic acid and m/z 851.2 → 704.9 for the internal standard. Good linearity was observed over their respective concentration range. The pharmacokinetic study showed that both compounds reached their peak concentration values (605.8 ± 35.6 ng/mL for chebulinic acid and 1327.1 ± 118.6 ng/mL for chebulagic acid) at the same time of 0.9 h following intraperitoneal injection administration. The two compounds could be detected in blood‐abundant tissues. The kidney had the highest concentrations (462.6 ± 138.5 ng/g for chebulinic acid and 1651.7 ± 167.7 ng/g for chebulagic acid) at 1 h post‐dose, followed by the heart, liver, spleen and lung.     

Comparative pharmacokinetics of prim-O-glucosylcimifugin and cimifugin by liquid chromatography-mass spectrometry after oral administration of Radix Saposhnikoviae extract, cimifugin monomer solution and prim-O-glucosylcimifugin monomer solution to rats

A sensitive and reliable liquid chromatography–mass spectrometry method has been developed and validated for simultaneous determination of cimifugin and prim‐O‐glucosylcimifugin in rat plasma after oral administration of Radix Saposhnikoviae (RS) extract, prim‐O‐glucosylcimifugin monomer solution and cimifugin monomer solution. Plasma samples were pretreated by protein precipitation with acetonitrile containing the internal standards puerarin and daidzein. LC separation was achieved on a Zorbax SB‐C₁₈ column (150 × 4.6 mm i.d., 5 µm) with 0.1% formic acid in water and methanol by isocratic elution. The detection was carried out in select‐ion‐monitoring mode with a positive electrospray ionization interface. The fully validated method was successfully applied to the pharmacokinetic study of the analytes in rats. A bimodal phenomenon appeared in the concentration–time curve of prim‐O‐glucosylcimifugin and cimifugin after oral administration of RS extract. Prim‐O‐glucosylcimifugin mainly transformed to cimifugin when it was absorbed into blood. Both absorption and elimination of cimifugin after oral administration of RS were longer than after administration of single cimifugin. The pharmacokinetic parameters (AUC_0–t, AUC_0–∞ and t_1/2) of prim‐O‐glucosylcimifugin and cimifugin by giving cimifugin monomer solution, prim‐O‐glucosylcimifugin monomer solution and RS extract had significant differences (P < 0.05). Copyright © 2012 John Wiley & Sons, Ltd.     

Simultaneous determination of corosolic acid and euscaphic acid in the plasma of normal and diabetic rat after oral administration of extract of Potentilla discolor Bunge by high‐performance liquid chromatography/electrospray ionization mass spectrometry

Potentilla discolor Bunge has been used for diabetes in China for a long time. Corosolic acid (CA) and euscaphic acid (EA), with significant anti‐diabetic activity, are two major triterpenoids in P. discolor. In this study, a specific, sensitive and convenient LC‐MS method has been developed for simultaneous determination of CA and EA in the plasma of normal and diabetic rats after oral administration of the extract of P. discolor. The chromatographic separation was achieved using an Alltima C₁₈ column (53 × 7.0 mm, i.d., 3 µm) with a mobile phase composed of 0.1% formic acid water and 0.1% formic acid acetonitrile at a flow rate of 1.0 mL/min. The detection was performed by MS with electrospray ionization interface in negative selected ion monitoring mode. All the validation data, such as specificity, linearity (r² > 0.9991 within 0.025–10.0 µg/mL), lower limit of quantitation (2.5 ng/mL), precision (intra‐ and inter‐day <14.7%), accuracy (<15.0%), recovery (85.7–110.8%) and stability were determined and all of them were within the required limits. This method was successfully applied for the evaluation of the pharmacokinetic behaviors of these two compounds in the plasma of normal and diabetic rats. Copyright © 2013 John Wiley & Sons, Ltd.     

Pharmacokinetics of salvianolic acid B,rosmarinic acid and Danshensu in rat after pulmonary administration of Salvia miltiorrhiza polyphenolic acid solution

A sensitive and accurate LC–MS/MS method was established for quantifying salvianolic acid B (Sal B), rosmarinic acid (Ros A) and Danshensu (DA) in rat plasma. Salvia miltiorrhiza polyphenolic acid (SMPA), active water‐soluble ingredients isolated and purified from Salvia miltiorrhiza Bge included Sal B, Ros A and DA. The pharmacokinetic analysis of Sal B, Ros A and DA after pulmonary administration of SMPA solution to rat was performed by LC–MS/MS. Results from the pharmacokinetic studies showed that the peak concentration of DA was 21.85 ± 6.43 and 65.39 ± 3.83 ng/mL after pulmonary and intravenous administration, respectively. DA was not detected at 2 h after administration. The absolute bioavailabilities of Sal B and Ros A were respectively 50.37 ± 27.04 and 89.63 ± 12.16% after pulmonary administration of 10 mg/kg SMPA solution in rats. The absolute bioavailability of Sal B increased at least 10‐fold after pulmonary administration, compared with oral administration. It was concluded that the newly established LC–MS/MS method was suitable for describing the pharmacokinetic characteristics of Sal B, Ros A and DA in rat after pulmonary administration of SMPA solution. The data from this study will provide a preclinical insight into the feasibility of pulmonary administration of SMPA.     

Qualitative and quantitative analysis of phenolic acid glycosides in Ginkgo biloba L. leaf,G. biloba leaf extract and its injection

Ginkgo biloba L. leaf (GBL) is one of the most commonly used medicinal plants in the world. Phenolic acids with biological activities have a relatively high content in G. biloba leaf extracts (GBE); therefore they are of great significance for the quality control of GBL, GBE and its preparations. However, there have been few studies focused on their analysis. In this work, 12 phenolic acids, including 11 phenolic acid glycosides, were identified by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC–Q-TOF/MS). Then, a method combining enzymolysis with HPLC was established for quantification of phenolic acid glycosides. It was found that the aglycones of phenolic acid glycosides mainly comprised five phenolic acids: 2,4,6-trihydroxybenzoic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid and p-coumaric acid. The quantitative method was validated, and the correlation coefficient (0.9993–0.9999), recovery (≥88.4%), repeatability (≤0.8%), and inter-day precision (≤5.5%) were satisfactory. Finally, the contents of glycosides of five phenolic acids in GBL, GBE and GBE injection from different sources were determined by the developed method. The method was accurate, repeatable and practicable, which could be helpful for the quantification of phenolic acid glycosides in other products containing GBL or GBE.