Simultaneous analysis of glycyrrhizin, paeoniflorin, quercetin, ferulic acid, liquiritin, formononetin, benzoic acid and isoliquiritigenin in the Chinese proprietary medicine Xiao Yao Wan by HPLC

Transdermal Drug Delivery using a Specialized Cavitation Seed for Ultrasound

GOAL

The Sonophoresis, which utilizes ultrasound for transdermal drug delivery (TDD), can improve the efficiency of drug delivery for a variety of drugs predominantly due to caviation effect. In order to increase the efficacy of sonophoresis, we propose an alternative cavitation seed specialized for sonophoresis, which can be concentrated on the skin surface by gravity adapting perfluorohexane as core.

METHODS

An in vitro and in vivo experiments were conducted to assess the effect of the specialized cavitation seed. High performance liquid chromatography was used for in vitro experiments on porcine skin with ferulic acid and an optical imaging system was used for in vivo experiments on rat model with fluorescein isothiocyanate-dextran (FD, 150 kDa), respecitively.

RESULTS

The amount of ferulic acid delivered by sonophoresis with the proposed cavitation seed was approximately 1,700 times greater than the amount delivered by diffusion. FD could be delivered to a depth of 500 ¼m under the skin, and the average total flux in the region of interest was increased 6.4-fold for the group using sonophoresis with the cavitation seed compared to the group using diffusion.

CONCLUSION

Conclusively, sonophoresis with the proposed cavitation seed demonstrated significant improvement in TDD and the possibility of macromolecule delivery into the skin.

SIGNIFICANCE

This approach has potential to be a main TDD method for variety of applications including medicine and cosmetics.

Sonophoresis Using Ultrasound Contrast Agents: Dependence on Concentration

Sonophoresis can increase skin permeability to various drugs in transdermal drug delivery. Cavitation is recognized as the predominant mechanism of sonophoresis. Recently, a new logical approach to enhance the efficiency of transdermal drug delivery was tried. It is to utilize the engineered microbubble and its resonant frequency for increase of cavitation activity. Actively-induced cavitation with low-intensity ultrasound (less than ~1 MPa) causes disordering of the lipid bilayers and the formation of aqueous channels by stable cavitation which indicates a continuous oscillation of bubbles. Furthermore, the mutual interactions of microbubble determined by concentration of added bubble are also thought to be an important factor for activity of stable cavitation, even in different characteristics of drug. In the present study, we addressed the dependence of ultrasound contrast agent concentration using two types of drug on the efficiency of transdermal drug delivery. Two types of experiment were designed to quantitatively evaluate the efficiency of transdermal drug delivery according to ultrasound contrast agent concentration. First, an experiment of optical clearing using a tissue optical clearing agent was designed to assess the efficiency of sonophoresis with ultrasound contrast agents. Second, a Franz diffusion cell with ferulic acid was used to quantitatively determine the amount of drug delivered to the skin sample by sonophoresis with ultrasound contrast agents. The maximum enhancement ratio of sonophoresis with a concentration of 1:1,000 was approximately 3.1 times greater than that in the ultrasound group without ultrasound contrast agent and approximately 7.5 times greater than that in the control group. These results support our hypothesis that sonophoresis becomes more effective in transdermal drug delivery due to the presence of engineered bubbles, and that the efficiency of transdermal drug delivery using sonophoresis with microbubbles depends on the concentration of microbubbles in case stable cavitation is predominant.

Simultaneous determination and assignment of 13 major flavonoids and glycyrrhizic acid in licorices by HPLC-DAD and Orbirap mass spectrometry analyses

To determine 13 flavonoids and glycyrrhizic acid in licorice (Glycyrrhiza spp.), several samples from different areas were examined by HPLC-DAD analysis. The analysis was performed on a Zorbax Extend-C18 (250 mm × 4.6 mm, 5 μm) column connected with a Zorbax Extend guard column (20 mm × 4.6 mm, 5 μm). The mobile phase consisted of (A) acetonitrile and (B) 0.026% aqueous H3PO4 (VV) using a gradient elution of 20%-25% A at 0-20 min, 25%-33% A at 20-30 min, 33%-50% A at 30-55 min, 50%-60% A at 55-65 min, and 60% A between 65 min and 80 min, and peaks were detected at 280 nm. The fourteen compounds were assigned by HPLC-Orbitrap MS methods. The regression coefficient for the linear equations for the 14 compounds ranged between 0.9998 and 1. The limits of detection and quantification lay in the range of 0.032-2.461 and 0.154-8.202 μg·mL(1), respectively. The relative recovery rates for the 14 compounds were in the range of 93.90%-106.73% with RSDs being less than 5%. Coefficient variations for intra-day and inter-day precisions were in the range of 0.27%-2.38% and 0.31%-3.51%, respectively. In summary, the validated method was applied to the simultaneous determination of the 14 components in 29 different licorice samples and was proven to be suitable for quality evaluation of licorices and their active fractions.

Characterization of phenolic compounds and antioxidant properties of Glycyrrhiza glabra L. rhizomes and roots

The present work aims to characterize and quantify the phenolic composition and to evaluate the antioxidant activity of Glycyrrhiza glabra L. (commonly known as licorice) rhizomes and roots.

Optimization of β-cyclodextrin cross-linked polymer for monitoring of quercetin

A novel method for the separation/analysis of quercetin was described, which was based on the investigation of the inclusion interactions of β-cyclodextrin cross-linked polymer (β-CDCP) with quercetin (Qu) and the adsorption behavior of Qu on β-CDCP. The inclusion interaction of β-CDCP with Qu was studied through FTIR, TGA and 13C NMR. Under the optimum conditions, the preconcentration factor of the proposed method was approximately 8.8, the β-CDCP could be used repeatedly for 30 times and offered better recovery. The linear range, limit of detection (LOD) and the relative standard deviation (RSD) was found to be 0.10-12.0 μg mL(-1), 4.6 ng mL(-1) and 3.10% (n=3, c=2.0 μg mL(-1)) respectively. This technique had been successfully applied to the determination of Qu in real samples.

Meta-analysis of randomized controlled trials to assess the effectiveness and safety of Free and Easy Wanderer Plus, a polyherbal preparation for depressive disorders

Free and Easy Wanderer Plus (FEWP) is a polyherbal preparation which therapeutic benefits have been extensively evaluated in patients with various depressive disorders. The purpose of this meta-analysis was to assess the overall effectiveness and safety of FEWP. Following systematic review, a total of 14 high-quality randomized controlled trials (RCTs) were identified and included in the meta-analysis. Statistically greater treatment effects were found in FEWP monotherapy compared to placebo and in FEWP combined with conventional anti-depressants (CADs) compared to CADs alone. Patients taking FEWP alone and combined with CADs experienced fewer adverse events of dizziness, headache, dry mouth, nausea, and constipation compared to CADs alone. These data suggest that FEWP may be an effective herbal agent in treating depressive symptoms. The addition of FEWP also enhances antidepressant effects of CADs. FEWP may have a higher safety profile compared to CADs.

Molecularly imprinted polymers for the selective extraction of glycyrrhizic acid from liquorice roots

A new Molecularly Imprinted Solid Phase Extraction (MISPE) protocol was developed for the selective extraction and purification of glycyrrhizic acid (GL) from liquorice roots. Non-covalent MIP were synthesized using methacrylic acid (MAA), 2-(dimethylamino)ethyl methacrilate (DMAEM) or 2-hydroxyethylmetacrylate (HEMA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent.

After the evaluation of the selectivity of the GL imprinted polymers, the performance of these materials as Solid Phase Extraction (SPE) sorbents was investigated. MIP having HEMA as functional monomer were found to be able to selectively extract almost 80% of GL content in liquorice roots. The proposed MISPE-HPLC procedure has good precision, thus it can be successfully used for the purification of GL from natural sources.

Chemiluminescence determination of ferulic acid by flow-injection analysis using cerium(IV) sensitized by rhodamine 6G

A simple, sensitive and rapid flow-injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with rhodamine 6G and ceric sulfate in sulphuric acid medium. Strong chemiluminescence signal was observed when ferulic acid was injected into the acidic ceric sulfate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 8.0 x 10(-6) to 1.0 x 10(-4) mol l(-1) and the detection limit for ferulic acid was 8.7 x 10(-9) mol l(-1). The relative standard deviation was 2.4% for 10 replicate analyses of 1.0 x 10(-5) mol l(-1) ferulic acid. The proposed method was applied to the determination of ferulic acid in Taita Beauty Essence samples with satisfactory results.