Ion-pair reversed-phase HPLC: assay validation of sodium tanshinone IIA sulfonate in mouse plasma

Preparation and performance of random- and oriented-fiber membranes with core-shell structures via coaxial electrospinning

The cells and tissue in the human body are orderly and directionally arranged, and constructing an ideal biomimetic extracellular matrix is still a major problem to be solved in tissue engineering. In the field of the bioresorbable vascular grafts, the long-term functional prognosis requires that cells first migrate and grow along the physiological arrangement direction of the vessel itself. Moreover, the graft is required to promote the formation of neointima and the development of the vessel walls while ensuring that the whole repair process does not form a thrombus. In this study, poly (l-lactide-co-ε-caprolactone) (PLCL) shell layers and polyethylene oxide (PEO) core layers with different microstructures and loaded with sodium tanshinone IIA sulfonate (STS) were prepared by coaxial electrospinning. The mechanical properties proved that the fiber membranes had good mechanical support, higher than that of the human aorta, as well as great suture retention strengths. The hydrophilicity of the oriented-fiber membranes was greatly improved compared with that of the random-fiber membranes. Furthermore, we investigated the biocompatibility and hemocompatibility of different functional fiber membranes, and the results showed that the oriented-fiber membranes containing sodium tanshinone IIA sulfonate had an excellent antiplatelet adhesion effect compared to other fiber membranes. Cytological analysis confirmed that the functional fiber membranes were non-cytotoxic and had significant cell proliferation capacities. The oriented-fiber membranes induced cell growth along the orientation direction. Degradation tests showed that the pH variation range had little change, the material mass was gradually reduced, and the fiber morphology was slowly destroyed. Thus, results indicated the degradation rate of the oriented-fiber graft likely is suitable for the process of new tissue regeneration, while the random-fiber graft with a low degradation rate may cause the material to reside in the tissue for too long, which would impede new tissue reconstitution. In summary, the oriented-functional-fiber membranes possessing core-shell structures with sodium tanshinone IIA sulfonate/polyethylene oxide loading could be used as tissue engineering materials for applications such as vascular grafts with good prospects, and their clinical application potential will be further explored in future research.

Preparation, preliminary pharmacokinetics and brain tissue distribution of Tanshinone IIA and Tetramethylpyrazine composite nanoemulsions

Objective: Tanshinone IIA (TSN) and Tetramethylpyrazine (TMP) were combined in a composite, oil-in-water nanoemulsions (TSN/TMP O/W NEs) was prepared to prolong in vitro and vivo circulation time, and enhance the bioavailability of TSN. Material and methods: Physicochemical characterization of TSN/TMP O/W NEs was characterized systematically. The in vitro dissolution and in vivo pharmacokinetic experiments of TSN/TMP O/W NEs were also evaluated. Result: A formulation was optimized, yielding a 32.5 nm average particle size, an encapsulation efficiency of over 95 %, and were spherical in shape as shown by TEM. TSN/TMP O/W NEs were shown to extend the release and availability in vitro compared to raw compounds. In pharmacokinetic study, the AUC_0→∞ and t_1/2 of the TSN/TMP O/W NEs were 481.50 mg/L*min and 346.39 min higher than TSN solution, respectively. Brain tissue concentration of TSN was enhanced with TSN/TMP O/W NEs over raw TSN and even TSN O/W NEs. Conclusions: Therefore, nanoemulsions are an effective carrier to increase encapsulation efficiency of drugs, improve bioavailability and brain penetration for TSN - which is further enhanced by pairing with the co-delivery of TMP, providing a promising drug delivery.

Sodium tanshinone IIA sulfonate: A review of pharmacological activity and pharmacokinetics

Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivate of tanshinone IIA (Tan IIA) which is an active lipophilic constitute of Chinese Materia Medica Salvia miltiorrhiza Bge. (Danshen). STS presents multiple pharmacological activities, including anti-oxidant, anti-inflammation and anti-apoptosis, and has been approved for treatment of cardiovascular diseases by China State Food and Drug Administration (CFDA). In this review, we comprehensively summarized the pharmacological activities and pharmacokinetics of STS, which could support the further application and development of STS. In the recent decades, numerous experimental and clinical studies have been conducted to investigate the potential treatment effects of STS in various diseases, such as heart diseases, brain diseases, pulmonary diseases, cancers, sepsis and so on. The underlying mechanisms were most related to anti-oxidative and anti-inflammatory effects of STS via regulating various transcription factors, such as NF-κB, Nrf2, Stat1/3, Smad2/3, Hif-1α and β-catenin. Iron channels, including Ca²⁺, K⁺ and Cl^- channels, were also the important targets of STS. Additionally, we emphasized the differences between STS and Tan IIA despite the interchangeable use of Tan IIA and STS in many previous studies. It is promising to improve the efficacy and reduce side effects of chemotherapeutic drug by the combination use of STS in canner treatment. The application of STS in pregnancy needs to be seriously considered. Moreover, the drug-drug interactions between STS and other drugs needs to be further studied as well as the complications of STS.

Preparation and characterisation of solid dispersions of tanshinone IIA, cryptotanshinone and total tanshinones

Total tanshinones are lipophilic active constituents extracted from Salvia miltiorrhiza Bge. Tanshinone IIA and cryptotanshinone are the major components in total tanshinones. However, the bioavailability of both compounds is low due to poor water solubility. To enhance the solubility and dissolution rate of tanshinone IIA, cryptotanshinone and total tanshinones, three common used hydrophilic carriers including PEG 6000, poloxamer 188 and PVP K30 were used to prepare the solid dispersions at different ratios, respectively. The solid dispersions were characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The results of powder X-ray diffraction confirmed the microcrystal state of total tanshinones in solid dispersions and no chemical interaction between total tanshinones and carriers was observed in FTIR spectra. The solubility and dissolution rate of tanshinone IIA and cryptotanshinone were significantly increased in all solid dispersions. Regarding tanshinone IIA, the solubility and dissolution rate of in solid dispersions prepared with poloxamer 188 were significantly higher than that with PEG 6000 and PVP K30. The higher solubility and dissolution rate of cryptotanshinone were obtained in solid dispersion of PVP K30 than that of PEG 6000 solid dispersions but no significant difference from poloxamer 188 solid dispersions. The results indicate that the superior carrier for preparation of tanshinone IIA and total tanshinones solid dispersions is poloxamer 188, and that for cryptotanshinone is PVP K30.

Determination of Sodium Tanshinone IIA Sulfonate in human plasma by LC-MS/MS and its application to a clinical pharmacokinetic study

An assay based on protein precipitation and liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed and validated for the quantitative analysis of Sodium Tanshinone IIA Sulfonate (STS) in human plasma. After the addition of dehydroepiandrosterone-D5-3-sulfate sodium salt (DHEAS-D5) as internal standard (IS) and formic acid, plasma samples were prepared by one-step protein precipitation with a mixture of acetonitrile and methanol. Isocratic mobile phase consisted of 0.4 mmol/L ammonium formate buffer (16 ppm formic acid)/acetonitrile (40/60, v/v) on a XSELECT™ HSS T3 column. Detection was performed on a triple-quadrupole mass spectrometer utilizing an electrospray ionization (ESI) interface operating in positive ion and selected reaction monitoring (SRM) mode with the precursor to product ion transitions m/z 373.3→357.1 for STS and m/z 373.0→97.8 for the IS. Calibration curves of STS in human plasma were linear (r=0.9957-0.9998) over the concentration range of 2-1000 ng/mL with acceptable accuracy and precision. The lower limit of quantification in human plasma was 2 ng/mL. The validated LC-MS/MS method has been successfully applied to a pharmacokinetic study of STS in Chinese healthy male volunteers.

Improvement in oral bioavailability and dissolution of tanshinone IIA by preparation of solid dispersions with porous silica

Objectives

This study aims to evaluate the oral bioavailability and dissolution of tanshinone IIA (tanIIA) by preparation of solid dispersions (SDs) with porous silica.

Methods

SDs of tanIIA were prepared using a solvent method. The physicochemical properties, dissolution property, drug stability and in-vivo performance of the SDs prepared were all evaluated.

Key findings

Compared with tanIIA alone and corresponding physical mixtures, tanIIA from SDs showed remarkably improved in-vitro dissolution rate. After forming the SDs, tanIIA changed into an amorphous state, which can infer from differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Fourier transform infrared spectroscopy (FTIR) also revealed the presence of interactions between tanIIA and porous silica in SDs. During the stability study, there is no significant decreasing in either the in-vitro dissolution or the drug content, which was observed following storage at room temperature for 12 months. The results of a pharmacokinetic study in rats showed the areas under the concentration–time curve from 0 h to 24 h (AUC0–24h) for the SDs and tanIIA were 1019.87 ± 161.819 mg/h per litre and 343.70 ± 75.628 mg/h per litre, respectively.

Conclusions

SDs with porous silica as carrier could achieve superior oral bioavailability by improving drug dissolution, whereas drug stability could be maintained.

Determination of Strong Acidic Drugs in Biological Matrices: A Review of Separation Methods

Strong acidic drugs are a class of chemical compounds that normally have high hydrophilicity and large negative charges, such as organophosphatic compounds and organosulphonic compounds. This review focuses on sample preparation and separation methods for this group of compounds in biological matrices in recent years. A wide range of separation techniques, especially chromatographic method, are presented and critically discussed, which include liquid chromatography (e.g., ion-pair and ion-exchange chromatography), capillary electrophoresis (CE), and other types. Due to the extremely low concentration level of target analytes as well as the complexity of biological matrices, sample pretreatment methods, such as dilute and shoot methods, protein precipitation (PP), liquid-liquid extraction (LLE), solid-phase extraction (SPE), degradation, and derivatization strategy, also play important roles for the development of successful analytical methods and thus are also discussed.

An attempt to stabilize tanshinone IIA solid dispersion by the use of ternary systems with nano-CaCO3 and poloxamer 188

Background:

Tanshinone IIA (TSIIA) on solid dispersions (SDs) has thermodynamical instability of amorphous drug. Ternary solid dispersions (tSDs) can extend the stability of the amorphous form of drug. Poloxamer 188 was used as a SD carrier. Nano-CaCO₃ played an important role in adsorption of biomolecules and is being developed for a host of biotechnological applications.

Objective:

The aim of the present study was to investigate the dissolution behavior and accelerated stability of TSIIA on solid dispersions (SDs) by the use of ternary systems with nano-CaCO₃ and poloxamer 188.

Materials and Methods:

The TSIIA tSDs were prepared by a spray-drying method. First, the effect of combination of poloxamer 188 and nano-CaCO₃ on TSIIA dissolution was studied. Subsequently, a set of complementary techniques (DSC, XRPD, SEM and FTIR) was used to monitor the physical changes of TSIIA in the SDs. Finally, stability test was carried out under the conditions 40°C/75% RH for 6 months.

Results:

The characterization of tSDs by differential scanning calorimetry analysis (DSC) and X-ray powder diffraction (XRPD) showed that TSIIA was present in its amorphous form. Fourier transforms infrared spectroscopy (FTIR) suggested the presence of interactions between TSIIA and carriers in tSDs. Improvement in the dissolution rate was observed for all SDs. The stability study conducted on SDs with nano-CaCO₃ showed stable drug content and dissolution behavior, over the period of 6 months as compared with freshly prepared SDs.

Conclusion:

SDs preparation with nano-CaCO₃ and poloxamer 188 may be a promising approach to enhance the dissolution and stability of TSIIA.

Preparation, characterization, and in vivo evaluation of tanshinone IIA solid dispersions with silica nanoparticles

We prepared solid dispersions (SDs) of tanshinone IIA (TSIIA) with silica nanoparticles, which function as dispersing carriers, using a spray-drying method and evaluated their in vitro dissolution and in vivo performance. The extent of TSIIA dissolution in the silica nanoparticles/TSIIA system (weight ratio, 5:1) was approximately 92% higher than that of the pure drug after 60 minutes. However, increasing the content of silica nanoparticles from 5:1 to 7:1 in this system did not significantly increase the rate or extent of TSIIA dissolution. The physicochemical properties of SDs were investigated using scanning electron microscopy, differential scanning calorimetry, X-ray powder diffraction, and Fourier transforms infrared spectroscopy. Studying the stability of the SDs of TSIIA revealed that the drug content of the formulation and dissolution behavior was unchanged under the applied storage conditions. In vivo tests showed that SDs of the silica nanoparticles/TSIIA had a significantly larger area under the concentration-time curve, which was 1.27 times more than that of TSIIA (P < 0.01). Additionally, the values of maximum plasma concentration and the time to reach maximum plasma concentration of the SDs were higher than those of TSIIA and the physical mixing system. Based on these results, we conclude that the silica nanoparticle based SDs achieved complete dissolution, increased absorption rate, maintained drug stability, and showed improved oral bioavailability compared to TSIIA alone.

Characterization and Stability of Tanshinone IIA Solid Dispersions with Hydroxyapatite

Solid dispersions of tanshinone IIA (TanIIA) using hydroxyapatite (HAp) as the dispersing carrier (TanIIA-HAp SDs) were prepared by the solvent evaporation method. The formed solid dispersions were characterized by scanning electron microscopy (SEM), differential scanning calorimetry analysis (DSC), X-ray powder diffraction (XRPD) and Fourier transforms infrared (FTIR) spectroscopy. The in vitro dissolution rate and the stability of TanIIA-HAp SDs were also evaluated. DSC and XRPD showed that TanIIA was changed from a crystalline to an amorphous form. FTIR suggested the presence of interactions between TanIIA and HAp in solid dispersions. The result of an in vitro dissolution study showed that the dissolution rate of TanIIA-HAp SDs was nearly 7.11-folds faster than free TanIIA. Data from stability studies for over one year of TanIIA-HAp SDs performed under room temperature revealed no significant differences in drug content and dissolution behavior. All these results indicated that HAp may be a promising carrier for improving the oral absorption of TanIIA.

Online nanoflow multidimensional fractionation for high efficiency phosphopeptide analysis

Despite intense, continued interest in global analyses of signaling cascades through mass spectrometry-based studies, the large-scale, systematic production of phosphoproteomics data has been hampered in-part by inefficient fractionation strategies subsequent to phosphopeptide enrichment. Here we explore two novel multidimensional fractionation strategies for analysis of phosphopeptides. In the first technique we utilize aliphatic ion pairing agents to improve retention of phosphopeptides at high pH in the first dimension of a two-dimensional RP-RP. The second approach is based on the addition of strong anion exchange as the second dimension in a three-dimensional reversed phase (RP)-strong anion exchange (SAX)-RP configuration. Both techniques provide for automated, online data acquisition, with the 3-D platform providing the highest performance both in terms of separation peak capacity and the number of unique phosphopeptide sequences identified per μg of cell lysate consumed. Our integrated RP-SAX-RP platform provides several analytical figures of merit, including: (1) orthogonal separation mechanisms in each dimension; (2) high separation peak capacity (3) efficient retention of singly- and multiply-phosphorylated peptides; (4) compatibility with automated, online LC-MS analysis. We demonstrate the reproducibility of RP-SAX-RP and apply it to the analysis of phosphopeptides derived from multiple biological contexts, including an in vitro model of acute myeloid leukemia in addition to primary polyclonal CD8(+) T-cells activated in vivo through bacterial infection and then purified from a single mouse.

Preparation and physicochemical characterizations of tanshinone IIA solid dispersion

This investigation describes a novel approach to prepare solid dispersions of tanshinone IIA using a laboratory-scale planetary ball mill. Poloxamer 188 was employed as the surfactant carrier to improve the solubility and dissolution of the poorly soluble drug, tanshinone IIA. Solubility and dissolution were evaluated compared to the corresponding physical mixtures and pure drug. Furthermore, the physicochemical properties of the solid dispersions were investigated using scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy and ultraviolet spectrophotometry. The solid dispersion significantly enhanced drug solubility and dissolution compared with pure drug and the physical mixtures. Scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry and Fourier transform infrared spectroscopy analyses of tanshinone IIA/poloxamer 188 system confirmed that there were intermolecular interactions between tanshinone IIA and poloxamer 188 and no conversion to crystalline material. Tanshinone IIA existed in a microcrystalline form in the system. These results suggested that improvement of the dissolution rate could be correlated to the formation of a eutectic mixture between the drug and the carrier. After 60 days the solid dispersion samples were chemically and physically stable. The present studies indicated that the planetary ball mill technique could be considered as a novel and efficient method to prepare solid dispersion formulations.

Ion-Pair Reversed-Phase HPLC Method for Determination of Sodium Tanshinone IIA Sulfonate in Biological Samples and Its Pharmacokinetics and Biodistribution in Mice

The ion-pair reversed-phase HPLC method for determination of sodium tanshinone IIA sulfonate (STS) in various biological samples was for the first time developed and validated, and was applied for pharmacokinetics and tissue distribution studies of intravenously administrated STS in mice. A linear relation was found between peak area and STS concentrations within the ranges of 0.1-5 micraog/ml for plasma, 0.1-5 microg/g of tissue for kidney homogenate, 0.1-20 microg/g of tissue for liver homogenate, 0.1-1 microg/g of tissue for heart, spleen and lung homogenates, respectively. In plasma and tissues, the limit of quantification (LOQ) and the limit of detection (LOD) for STS were 100 ng/ml and 20 ng/ml. In all biological specimens, the average inter- and intra-day precision of STS were within 4.9%. The recoveries were more than 92% at all concentration levels in each type of biological specimens. STS plasma concentration-time data were best fitted with a two-compartment model, characterized by an initial rapid phase of drug concentration decrease, and a slower terminal elimination phase. The pharmacokinetics of STS was characterized with a distribution half-life (t(1/2alpha)) of 1.2+/-0.18 min, a terminal half-life (t(1/2beta)) of 21.6+/-2.4 min, a distribution volume (V) of 0.057+/-0.011 l/kg, a plasma clearance (CL) of 0.86+/-0.12 l/h/kg and an AUC(0-infinity) of 58.41+/-6.21 microg x h/ml. STS was widely distributed into most tissues and was obviously accumulated in liver. This results indicated that STS may be promising to treat liver disease.

Determination of sodium tanshinone IIA sulfonate in plasma by liquid chromatography-electrospray ionisation-tandem mass spectrometry

Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of tanshinone IIa, an important lipophilic component contained in Salvia miltiorrhizae. A simple, sensitive and robust quantification method for STS based on LC-ESI-MS/MS was developed and validated, and has been successfully applied to the pharmacokinetic study. Liquid-liquid extraction was used for extracting STS from biological samples, with a satisfactory recovery exceeding 75% at all test concentrations. Isocratic mobile phase consisted of 75% acetonitrile and 25% water containing 0.005% ammonia acetate (pH 3). Good retention and baseline separation for STS and the selected internal standard, diclofenac sodium, were obtained on a Shim-pack VP-ODS analytical column under this condition. The method was linear in the concentration range of 1-500 ng/mL. The intra- and inter-day precisions (RSD%) were within 9.0%. The deviation of the assay accuracies was within +/-10.0%. STS was proved to be stable during all sample storing, preparation and analytic procedures. With a lower limit of quantitation at 1 ng/mL, this method has been proved to be sensitive enough for the pharmacokinetic study of STS. The plasma profile of STS followed a single intravenous dosing was well fitted to a three compartmental model.