Pharmacokinetics of maslinic and oleanolic acids from olive oil - Effects on endothelial function in healthy adults. A randomized, controlled, dose-response study.

To date, pharmacokinetics of maslinic (MA) and oleanolic (OA) acids, at normal dietary intakes in humans, have not been evaluated, and data concerning their bioactive effects are scarce. We assessed MA and OA pharmacokinetics after ingestion of olive oils (OOs) with high and low triterpenic acid contents, and specifically the effect of triterpenes on endothelial function. We performed a double-blind, dose-response, randomized, cross-over nutritional intervention in healthy adults, and observed that MA and OA increased in biological fluids in a dose-dependent manner. MA bioavailability was greater than that of OA, and consumption of pentacyclic triterpenes was associated with improved endothelial function. To the best of our knowledge, this is the first time MA pharmacokinetics, and effects on endothelial function in vivo, have been reported in humans.

Analysis of five active ingredients of Er-Zhi-Wan, a traditional Chinese medicine water-honeyed pill, using the biopharmaceutics classification system.

Er-Zhi-Wan (EZW) is a traditional Chinese medicine with many clinical applications and used as a health product in East Asia. Five active ingredients (salidroside, specnuezhenide, nuezhenoside, luteolin, and oleanolic acid) were screened out from EZW to develop an in vitro rapid evaluation method for the classification of in vivo drug absorption behavior by biopharmaceutics classification system (BCS). Ultra-performance liquid chromatography was used for quantitative analysis. Solubility and permeability were assayed by equilibrium solubility and multiple models: everted rat intestinal sac model, cultured Caco-2 cells, octanol-water partition coefficient (LogP) method. The BCS properties of drugs were predicted using software applications, and the correlations of measured and predicted values of factors affecting oral drug absorption were calculated. The results were verified by measuring the absolute bioavailability of the active ingredients. Salidroside, specnuezhenide, and nuezhenoside were classified as BCS class III drugs, and luteolin was classified as a BCS class III/I drug because of the difference in LogP and intestinal permeability. Oleanolic acid was classified as a BCS class II/IV drug in acidic media and BCS class I/III drug in other media. Overall, EZW may be classified as a BCS class III drug, and permeability was identified as the primary factor limiting absorption. The results provide a novel method for the evaluation of the in vivo absorption of oral traditional Chinese medicines.

Effects of Animal Strain, Dose, and Cotreatment with Saikosaponin b2 on the Pharmacokinetics of Saikosaponin a in Rats.

BACKGROUND AND OBJECTIVES: Radix Bupleuri (RB, Chaihu in Chinese) has been used as a traditional medicine for more than 2000 years in China, Japan, Korea, and other Asian countries. Saikosaponin a (SSa), the most abundant saikosaponin in RB, exhibits various pharmacological activities, including anti-inflammatory, antitumor, antiviral, immunoregulatory, neuromodulatory, and hepatoprotective activities. A comprehensive study of the pharmacokinetic characteristics of SSa is needed to gain a detailed understanding of its pharmacodynamic mechanism. METHODS: Here, we determined the effects of rat strain (Sprague Dawley and Wistar), oral dose, and cotreatment with saikosaponin b2 (SSb2) on the pharmacokinetics of SSa by measuring SSa in plasma via LC-MS/MS. RESULTS: The results showed that the absorption of SSa in Wistar rats was statistically superior to its absorption in Sprague Dawley rats based on pharmacokinetic parameters such as the area under the concentration-time curve (AUC0-t) and the peak concentration (Cmax). Pharmacokinetic studies of different doses of SSa in Wistar rats revealed that the systemic exposure of SSa, based on AUC values, increased disproportionately with dose, indicating that SSa exhibits non-dose-proportional pharmacokinetics. In addition, our studies showed that SSb2, a characteristic component of vinegar-baked Radix Bupleuri (VBRB), inhibits the absorption of SSa in rats. CONCLUSIONS: The pharmacokinetic data for SSa obtained in this study will play an important role in attempts to better understand the fate of SSa in rats and to explore how these saikosaponins are likely to exert their pharmacological effects in vivo. In addition, further research is needed to elucidate the interactions of saikosaponins with metabolic enzymes and transporters in order to account for the phenomena observed in this study.

A rapid and sensitive UHPLC-MS/MS method for the determination of celosin A in rat plasma with application to pharmacokinetic study.

Celosin A (CA), a natural compound isolated from Celosia argentea L., has been shown significant hepatoprotective effect on AHNP-induced liver injury. This study described a rapid and sensitive ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) assay for determination of CA in rat plasma. Methanol-mediated precipitation was used for sample pretreatment. Chromatographic separation was achieved on a T3 column with gradient elution using water and acetonitrile as mobile phase. Determination was obtained using an electrospray ionization source in negative selected reaction monitoring mode at the transitions of m/z 793.3 → m/z 661.2 and m/z 955.6 → m/z 793.2 for CA and IS, respectively. The assay was linear over the concentration range 0.25-2500 ng/mL (r > 0.995) with a lowest limit of quantification (LLOQ) of 0.25 ng/mL. The intra- and inter-day precisions (RSD) were 1.65-9.84 and 2.46-13.49%, respectively, while accuracy (RR) ranged from 96.21 to 99.45%, respectively. The recovery ranged from 95.09 to 102.22% and the matrix effect from 98.29 to 100.13%. The analyte was stable under the tested storage conditions. The method has been successfully applied to a preclinical pharmacokinetic study in rats after a single intravenous (2 mg/kg) or oral (50 mg/kg) administration. The oral bioavailability of CA was ~1.94%; in addition, there was no difference between male and female rats. This is the first time of the use of an UHPLC-MS/MS method for determination of CA concentration in rat plasma and for evaluation of its pharmacokinetic behavior.

Pharmacokinetic Comparisons of Multiple Triterpenic Acids from Jujubae Fructus Extract Following Oral Delivery in Normal and Acute Liver Injury Rats.

Jujubae Fructus, the dried fruit of Ziziphus jujuba, has been used as Chinese medicine and food for centuries. Triterpenic acids have been found to be the major bioactive constituents in Jujubae Fructus responsible for their hepatoprotective activity in previous phytochemical and biological studies, while few pharmacokinetic studies have been conducted. To reveal the kinetics of the triterpenic acids under the pathological liver injury state, an established ultra-performance liquid chromatography coupled with a mass spectrometry method was applied for the simultaneous quantitation of seven triterpenic acids (ceanothic acid, epiceanothic acid, pomonic acid, alphitolic acid, maslinic acid, betulinic acid, and betulonic acid) in plasma samples of normal and acute liver injury rats induced by CCl4. The results showed that there were significant differences (p < 0.05) in the pharmacokinetic parameters of seven triterpenic acids between model and normal groups. The AUC0­t and AUC0­∞ of epiceanothic acid (5227 ± 334 µg⋅h/L vs. 1478 ± 255 µg ⋅ h/L and 6127 ± 423 µg ⋅ h/L vs. 1482 ± 255 µg ⋅ h/L, respectively) and pomonic acid (4654 ± 349 µg ⋅ h/L vs. 1834 ± 225 µg ⋅ h/L and 4776 ± 322 µg ⋅ h/L vs. 1859 ± 230 µg ⋅ h/L, respectively) in model rats were significantly higher than those in normal rats, and the CLz/F of them were significantly decreased (0.28 ± 0.02 L/h/kg vs. 1.36 ± 0.18 L/h/kg and 19.96 ± 1.30 L/h/kg vs. 53.15 ± 5.60 L/h/kg, respectively). In contrast, the above parameters for alphitolic acid, betulinic acid and betulonic acid exhibited the quite different trend. This pharmacokinetic research might provide useful information for the clinical usage of triterpenic acids from Jujubae Fructus.

Bioavailability of wilforlide A in mice and its concentration determination using an HPLC-APCI-MS/MS method.

Wilforlide A (WA), an active compound in Tripterygium wilfordii Hook F (TW) which is a traditional Chinese medicine for treatment of autoimmune diseases, is a quality control marker for TW product. At present, the bioavailability/pharmacokinetics of WA is not known. Such information is not only essential to evaluate the relevance of WA as a quality control maker, but also important for future clinical efficacy studies. Therefore, a high-performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometric method (HPLC-APCI-MS/MS) was developed and applied to a bioavailability/pharmacokinetic study of WA. WA and celastrol (the internal standard, IS) were extracted by a liquid-liquid extraction method using methyl tert-butyl ether. Multiple reaction monitoring (MRM) scanning in positive ionization mode was used to monitor the transition of m/z 455.1 to 191.3 for WA and 451.3 to 201.2 for IS. This method was validated and applied to a pharmacokinetic study of WA in mice following intravenous administration (IV, 1.2 mg/kg), intraperitoneal injection (IP, 6 mg/kg) and oral administration (PO, 30 mg/kg). The lower limit of quantification (LLOQ) for WA was 10 ng/ml. The intra- and inter-day precision was found to be within 15.4% while the accuracy within 94.1-115.7% for all the quality control and LLOQ samples. The samples were stable under all the usual storage and experimental conditions. The terminal elimination half-lives were 14.7, 9.1 and 22.7 min following IV, IP and PO dosing, while the absolute bioavailability for IP and PO WA were 9.39% and 0.58% respectively. These results indicated that the HPLC-APCI-MS/MS assay was suitable for the pharmacokinetic study of WA. WA was found poorly absorbed when given orally and therefore it may not be a relevant marker for the oral TW products in the market.

Rapid and Sensitive Quantification of Ursolic Acid and Oleanolic Acid in Human Plasma Using Ultra-performance Liquid Chromatography-Mass Spectrometry.

Ultra-performance liquid chromatography (UPLC) interfaced with atmospheric pressure chemical ionization mass-spectrometry was used to separate and quantify ursolic acid (UA) and oleanolic acid (OA) in human plasma. UA and OA were extracted from 0.5 mL human plasma using supported liquid extraction and separated utilizing an Acquity UPLC HSS column. The method has been validated for both UA and OA quantitation with a limit of detection of 0.5 ng/mL. The UPLC separations are carried out with isocratic elution with methanol and 5 mM ammonium acetate in water (85:15) as a mobile phase at a flow rate of 0.4 mL/min. The assay was linear from 1 ng/mL to 100 ng/mL for both analytes. The total analysis time was 7 min with the retention times of 3.25 (internal standard), 3.65 (UA) and 3.85 min (OA). Recovery of drug from plasma ranged from 70% to 115%. Analysis of quality control samples at 3, 30 and 80 ng/mL (n = 14) had an intra-day coefficient of variation of 9.9%, 4.3% and 5.5%, respectively. A proof-of-concept study in human patients who consumed apple peels indicates that this analytical method could be applied to clinical studies of UA and/or OA in human subjects.

Determination and Pharmacokinetics of WGA in Rat Plasma by LC-MS After Oral Administration of Xanthoceras sorbifolia Bunge Extract.

3-O-(3-O-angeloyl-6-O-ß-D-glucopyranosyl)-ß-D-glucopyranosyl-28-O-(2-α-L-rhamnopyranosyl-6-O-ß-D-glucopyranosyl)-ß-D-glucopyranosyl-16-deoxybarringtogenol A (WGA) is a potential anti-AD (Alzheimer's disease) active compound isolated from the husks of Xanthoceras sorbifolia Bunge. A rapid and accurate high-performance liquid chromatography-mass spectrometry (LC-MS) method was developed and validated for the quantification of WGA in rat plasma. Digoxin was used as internal standard (IS). Sample preparation was performed by liquid-liquid extraction using ethyl acetate-isopropanol (1:1, v/v). HPLC separation was carried out using a Venusil MP C18 column (150 mm × 4.6 mm, 5 µm). Isocratic elution was performed using methanol: water (70:30, v/v) as the mobile phase, at a flow rate of 0.8 mL/min. Analysis was performed in selected ion monitoring mode with a positive electrospray ionization interface. No endogenous interference was observed at the retention time of the analyte because of the high specificity of selected ion monitoring mode. The assay was validated to demonstrate the selectivity, linearity, recovery, accuracy, precision and stability. The lower limit of quantification (LLOQ) was 10.0 ng/mL. The developed and validated method has been successfully applied to the quantification and pharmacokinetic study of WGA in rats after oral administration of X. sorbifolia Bunge extract.

Simultaneous determination of saikosaponin a, paeonol, and imperatorin, components of DA-9805, in rat plasma by LC-MS/MS and application to a pharmacokinetic study.

DA-9805 is a new botanical antiparkinson drug candidate formulated using an ethanolic extract of the root of Bupleurum falcatum, the root cortex of Paeonia suffruticosa, and the root of Angelica dahurica. In this study, a sensitive and rapid LC-MS/MS method was developed to simultaneously determine, saikosaponin a, paeonol, and imperatorin, three active/representative ingredients of DA-9805, in rat plasma. Plasma was extracted by mixture of ethyl acetate and methyl tertiary butyl ether. Chromatographic separation was carried out using a C18 column and a gradient elution of mobile phases consisting of 5mM formic acid in water and acetonitrile. Total chromatographic run time was 10.5min. Multiple reaction monitoring mode was used for mass spectrometry; the transitions were m/z 779.5→617.2 for saikosaponin a in negative-ion mode, m/z 167→149 for paeonol and m/z 271.1→203 for imperatorin in positive-ion mode. Calibration curves were constructed in the range of 0.5-1000ng/mL for saikosaponin a, 20-10000ng/mL for paeonol, and 0.2-1000ng/mL for imperatorin. All the validation data, including the selectivity, linearity, precision, accuracy, recovery, matrix effect, and stability satisfied the acceptance requirements. The method was successfully applied in a pharmacokinetic study of saikosaponin a, paeonol, and imperatorin following oral administration of DA-9805.

Validated UPLC-MS/MS method for simultaneous quantification of eight saikosaponins in rat plasma: Application to a comparative pharmacokinetic study in depression rats after oral administration of extracts of raw and vinegar-baked Bupleuri Radix.

A sensitive and efficient UPLC-MS/MS method was developed and validated for simultaneous quantification of eight saikosaponins (SSa, SSb1, SSb2, SSb3, SSb4, SSc, SSd and SSf) in rat plasma. Furthermore, comparative pharmacokinetic profiles of these sakosaponins were investigated, following oral administration of extracts of raw and vinegar-baked Bupleuri Radix to depression rats. Biosamples were processed with liquid-liquid extraction technique using ethyl acetate. Chromatographic separation was accomplished on Waters BEH C18 UPLC column. 0.05% formic acid in water and acetonitrile as mobile phase was used at a flow rate of 0.40mL/min. The analytes and internal standard, digoxin, were detected using negative ion electrospray ionization in multiple reaction monitoring mode. The lower limit of quantification was less than 0.62ng/mL for the each analyte. The validation parameters investigated, which were specificity, precision, accuracy, matrix effect, recovery and stability, were well within acceptable limits. Results showed that for some of analytes, AUC0-t and Cmax were significantly different after oral administration of extracts of raw and vinegar-baked Bupleuri Radix. Moreover, the pharmacokinetic study in pathological state could provide more useful information to guide the clinical usage of Bupleuri Radix.

Determination of oleanolic acid in human plasma and its association with olive oil intake in healthy Spanish adults within the EPIC Spain cohort study.

SCOPE: Oleanolic acid (OA) is an important triterpenic compound found in olive oil, however little is known about its concentrations in human plasma. We aimed to determine plasma OA levels in a healthy Spanish population and compare them with estimates of dietary olive oil intake. METHODS AND RESULTS: The final study sample included 141 individuals randomly selected from the European Prospective Investigation into Cancer and Nutrition Spanish cohort. Dietary olive oil intake was estimated using validated dietary history questionnaires. OA concentrations were determined in plasma (from the participants' stored blood samples) using a HPLC-MS method. Correlation coefficients between OA and olive oil intake were calculated, adjusting for center; sex; age; consumption of olives, apples, grapes, and red wine; and fasting state. The mean OA concentration in olive oil nonconsumers was 0.72 ng/mL (SD 0.82), while in the high olive oil intake group it was 1.32 ng/mL (SD 1.14). The fully adjusted partial Spearman correlations coefficients reached 0.36 (p-value < 0.001) overall, varying minimally by sex and fasting state. CONCLUSION: This is the first study providing steady-state concentrations of triterpenes in humans. The results show that there was low-to-moderate correlation between OA concentrations and olive oil intake in this population.

Pharmacokinetic study of ardisiacrispin A in rat plasma after intravenous administration by UPLC-MS/MS.

In this work, a sensitive and selective UPLC-MS/MS method for determination of ardisiacrispin A in rat plasma was developed. Cyasterone used as an internal standard (IS) and protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 × 100 mm, 1.7 µm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used for quantification using target fragment ions m/z 1083.5 → 407.1 for ardisiacrispin A and m/z 521.3 → 485.2 for IS. Calibration plots were linear throughout the range 5-2000 ng/mL for ardisiacrispin A in rat plasma. Mean recoveries of ardisiacrispin A in rat plasma ranged from 80.4 to 92.6%. The values of RSD of intra- and inter-day precision were both <11%. The accuracy of the method was between 97.3 and 105.6%. The method was successfully applied to pharmacokinetic study of ardisiacrispin A after intravenous administration in rats.

Preparation, characterization and in vivo pharmacokinetic study of PVP-modified oleanolic acid liposomes.

The primary purpose of the present study was to design and optimize a liposomal formulation of the poorly water-soluble drug oleanolic acid (OA) to improve its oral bioavailability, and prolong the duration of therapeutic drug level. Liposomes containing a soybean lecithin and cholesterol lipid bilayer, a protective hydrophilic polyvinylpyrrolidone-K30 (PVP-K30) coating, and a protective bile salt, sodium deoxycholate, were prepared by a thin-film dispersion method coupled with sonication. Several properties of the PVP-modified OA liposomes (PVPOALs), including surface morphology, particle size, zeta potential and entrapment efficiency were extensively characterized. The pharmacokinetic parameters of PVPOALs in rats were determined by UPLC-MS/MS following oral administration. The results of the characterization studies demonstrated that PVPOALs were spherical particles with an average particle size of 179.4nm and a zeta potential of -28.8mV. The drug encapsulation efficiency was more than 90%. After freeze-drying, the prepared liposomes possessed high entrapment efficiency of more than 90%. The mean particle size was 194.8nm, and the zeta potential was about -30.9mV. Furthermore, as compared to the commercial tablets, the liposomal formulation enhanced the maximum plasma concentration (Cmax) of OA by 6.90-fold in rat plasma. The relative bioavailability of PVP-modified liposomes was 607.9%. The research work in the paper suggests that PVP-modified liposomes could serve as a practical oral preparation for OA in future cancer therapy.

Development and validation of a quantification method for oleanolic acid and hederagenin in rat plasma: application to the pharmacokinetic study.

A rapid and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and validated for simultaneous quantification of oleanolic acid and hederagenin in rat plasma. After the two analytes were extracted with liquid-liquid extraction, chromatographic separation was performed on a C18 column with acetonitrile and water (85:15, v/v) as mobile phase at a flow rate of 0.4 mL/min. Calibration curves exhibited good linearity (r > 0.995) over the ranges of 0.41-82.0 ng/mL for oleanolic acid and 0.32-64.0 ng/mL for hederagenin, respectively. The lower limit of quantifications (LLOQs) in plasma were 0.41 ng/mL for oleanolic acid and 0.32 ng/mL for hederagenin. The established LLOQs were within the concentration needed for the assay in plasma, which met the requirements to evaluate their pharmacokinetics of oleanolic acid and hederagenin. This developed assay was successfully applied in the pharmacokinetic study of oleanolic acid and hederagenin in rats after oral administration of Rhizoma Clematidis extract.

Comparative pharmacokinetic analysis of extracts of crude and wine-processed Dipsacus asper in rats by a sensitive ultra performance liquid chromatography-tandem mass spectrometry approach.

The purpose of this study is to establish and validate an UPLC-MS/MS approach to determine 4-caffeoylquinic acid, chlorogenic acid, 3,5-dicaffeoylquinic acid, loganic acid, loganin, sweroside, dipsacoside B and asperosaponin VI from extracts of crude and wine-processed Dipsacus asper in biological samples and apply the approach to a comparative pharmacokinetic study. A Waters BEH C18 UPLC column was employed with acetonitrile/0.2% formic acid-water as mobile phases. The mass analysis was carried out in a triple quadrupole mass spectrometer using multiple reaction monitoring (MRM) with negative scan mode. A one-step protein precipitation by acetonitrile was performed to extract the eight analytes from plasma. Our results revealed that all of the calibration curves displayed good linear regression (r2>0.9990). The lower limits of quantification (LLOQ) were determined as 10.0, 9.6, 8.9, 9.1, 9.2, 9.8, 10.1 and 9.8ng/mL. The intra-day and inter-day precisions (RSD) of the eight compounds at high, medium and low levels were less than 4.94% and the bias of the accuracies ranged from -3.89% to 3.95%.The extraction recoveries of the eight compounds were from 90.4% to 100.2% and the matrix effects ranged from 89.3% to 100.1%. The stabilities of these compounds were investigated by analyzing six replicates of QC samples at three different concentrations following storage at 25°C for 4h, -80°C for 30days, three-freeze-thaw cycles, and 4°C for 24h. All the samples showed satisfactory precision and accuracy after various stability tests. Pharmacokinetic parameters were estimated using a non-compartment model. Compared with the crude group, the parameters of Cmax and AUC0-t of 4-caffeoylquinic acid, loganic acid, loganin and asperosaponin VI increased remarkably (p<0.05) after oral administration of the aqueous extract of wine-processed Dipsacus asper, indicating that wine-processing could enhance bioavailability of 4-caffeoylquinic acid, loganic acid, loganin and asperosaponin VI.

Pharmacokinetic parameters of three active ingredients hederacoside C, hederacoside D, and ɑ-hederin in Hedera helix in rats.

In Hedera helix hederacoside C, hederacoside D, and ɑ-hederin are three major bioactive saponins and play pivotal roles in the overall biological activity. In this study, a specific and sensitive ultra-high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the quantification of three major bioactive saponins in rat plasma. Chromatographic separation was performed on a reversed-phase Thermo Hypersil GOLD C18 column (2.1 mm × 50 mm, 1.9 µm) using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid. The assay was successfully applied to study the pharmacokinetic behavior of the three analytes in rats after oral and intravenous administration of a mixture of saponins (hederacoside C, hederacoside D, and ɑ-hederin). Further research was performed to compare the pharmacokinetic behavior of the three analytes after the oral administration of a mixture of saponins and an extract of saponins from Hedera helix, and results showed that double peaks were evident on concentration-time profile for each of the three saponins. The difference in the pharmacokinetic characteristics of three saponins between a mixture of saponins and an extract of saponins from Hedera helix was found in rat, which would be beneficial for the preclinical research and clinical use of Hedera helix.

An ultra-high-performance liquid chromatography-tandem mass spectrometric method for the determination of hederacoside C, a drug candidate for respiratory disorder, in rat plasma.

Hederacoside C is a principal bioactive pharmaceutical ingredient of Hedera helix leaf extracts. H. helix extracts have long been used in folk medicine for the treatment of respiratory disorders. Currently, hederacoside C is investigated as a promising candidate for the treatment of respiratory diseases. In this study, an accurate, sensitive, rapid, and reliable bioanalytical method was developed for the determination of hederacoside C in rat plasma using ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). For sample preparation, plasma proteins were precipitated with 0.1% acetic acid in acetonitrile. Waters UPLC BEH C18 (2.1mm I.D.×100mm, 1.7µm) column was used for chromatographic separation. A gradient elution of mobile phases consisting of 0.02% acetic acid in distilled water (solvent A) and 0.02% acetic acid in acetonitrile (solvent B) was used at a flow rate of 0.3mL/min. The multiple reaction monitoring (MRM) mode was used for mass spectrometric detection; the MRM transitions were m/z 1219.7→m/z 469.2 for hederacoside C and m/z 1108.3→m/z 221.2 for ginsenoside Rb1 (internal standard) in the negative ionization mode. A calibration curve was constructed in the range of 10-1000ng/mL. The intra- and inter-day precision and accuracy were within 5%. The developed UPLC-MS/MS method was successfully applied in a pharmacokinetic study of hederacoside C in rats. Hederacoside C was quickly but inadequately absorbed from the gastrointestinal tract of rats resulting in extremely low bioavailability and relatively slow clearance.

Effect of a controlled-release drug delivery system made of oleanolic acid formulated into multivesicular liposomes on hepatocellular carcinoma in vitro and in vivo.

The aim of the present study was to develop a novel dosage form of multivesicular liposomes for oleanolic acid (OA) to overcome its poor solubility, prolong therapeutic drug levels in the blood, and enhance the antitumor effect on hepatocellular carcinoma. OA-encapsulated multivesicular liposomes (OA-MVLs) were prepared by a double-emulsion method, and the formulation was optimized by the central composite design. The morphology, particle size, and drug-loading efficiency of OA-MVLs were investigated. Furthermore, OA-MVLs were also characterized both in vitro and in vivo. The results showed that OA-MVLs were spherical particles with an average particle size of 11.57 µm and an encapsulation efficiency of 82.3%±0.61%. OA-MVLs exhibited a sustained-release pattern in vitro, which was fitted to Ritger-Peppas equation. OA-MVLs inhibited the growth of human HepG2 cells which was confirmed by the MTT assay and fluorescence microscopy detection. The in vivo release of OA from OA-MVLs exhibited a sustained manner, indicating a longer circulation time compared to OA solution. The in vivo toxicity study indicated that medium-dose OA-MVLs exerted no toxic effect on the hosts. Importantly, OA-MVLs suppressed the growth of murine H22 hepatoma and prolonged the survival of tumor-bearing mice. In conclusion, the poorly soluble OA could be encapsulated into MVLs to form a novel controlled-release drug delivery system. The present study may hold promise for OA-MVLs as a new dosage form for sustained-release drug delivery in cancer therapy.

UFLC-MS/MS determination and pharmacokinetic studies of six Saikosaponins in rat plasma after oral administration of Bupleurum Dropping Pills.

A rapid and sensitive ultra fast liquid chromatography tandem mass spectrometry method (UFLC-MS/MS) was developed and validated for the simultaneous determination of six Saikosaponins (SSs) (SSa, SSb1, SSb2, SSd, SSc, SSf) of Bupleurum Dropping Pills (BDP) in rat plasma using chloramphenicol as the internal standard (IS). The SSs were separated using an ACQUITY UPLC(®) BEH C18 column (50 mm × 2.1mm, 1.7 µm) and detection of these compounds were done by using a Qtrap 5500 mass spectrometer coupled with negative electrospray ionization (ESI) source under the multiple reaction monitoring (MRM) mode. According to regulatory guidelines, the established method was fully validated and results were showed within acceptable limits. The lower limit of quantifications (LLOQs) of all analytes were 0.2 ng/mL. The validated method was successfully applied into a pharmacokinetic study of orally administered BDP in rats.

Determination and validation of chikusetsusaponin IVa in rat plasma by UPLC-MS/MS and its application to pharmacokinetic study.

A novel, sensitive and rapid ultra-performance liquid chromatography-tandem mass spectrometric method for the quantification of chikusetsusaponin IVa (CHS-IVa) in rat plasma was established and validated. Plasma samples were pre-treated by precipitation of protein with acetonitrile and chromatographed on a Waters Symmetry C18 analytical column (4.6 × 50 mm, i.d., 3.5 µm) using a mobile phase consisting of methanol and water containing 0.05% formic acid (55:45, v/v) at a flow rate of 0.4 mL/min. The deprotonated molecular ions [M - H](-) were employed in electrospray negative ionization mode and selected reaction monitoring transitions were performed for detection. The calibration curves exhibited good linearity (r > 0.99) over the range of 0.5-1000 ng/mL for CHS-IVa. The recoveries of CHS-IVa were >92.5% and exhibited no severe matrix effect. This method was successfully applied in the pharmacokinetic study of CHS-IVa in rats. For oral administration, the plasma concentrations of CHS-IVa increased to a peak value at 0.35 ± 0.14 h, followed by a gradual decrease to the lower limit of quantitation in 24 h. For intravenous administration, the plasma concentrations of CHS-IVa decreased quickly (t1/2 , 1.59 ± 0.25 h). The absolute bioavailability of CHS-IVa in rats was 8.63%. Copyright © 2016 John Wiley & Sons, Ltd.