Simultaneous determination of seven flavonoids, two phenolic acids and two cholesterines in Tanreqing injection by UHPLC-MS/MS.

A new ultra-high performance liquid chromatography combined with triple quadrupole mass spectrometry was developed to evaluate the quality of Tanreqing injection. Seven flavonoids (Rutin, Baicalin, Scutellarin, Chrysin-7-O-Beta-d-glucoronide, Oroxylin A-7-O-ß-d-glucoronide, Wogonin, Luteolin-7-O-glucoside), two phenolic acids (Chlorogenic acid, Caffeic acid) and two cholesterines (Ursodeoxycholic acid, Chenodeoxycholic acid) in Tanreqing injection could be measured simultaneously. For the determination of the eleven compounds, the conditions were set as follows: The mobile phase was a gradient of 0.1% aqueous formic acid solution (A) and acetonitrile (B); the flow rate was 0.2 mL min-1, the column was Acquity UPLC HSS T3 column (2.1 mm × 100 mm, 1.8 µm); and the multiple-reaction monitoring (MRM) with a negative electro spray ionization interface (ESI-) was selected. Within the test ranges, all the standard regression curves showed excellent linear regression (r > 0.99). In terms of (relative standard deviation) RSDs, the precision, repeatability and stability of the eleven compounds were all lower than 3%. The recovery rates of Tanreqing injection and the RSD were 97.8-103.7% and 0.4%-2.0%, respectively. The RSD value was in accordance with the requirements of less than 3.0%. This method has been successfully used in the analysis of Tanreqing injection. In summary, a fast, accurate and reliable UPLC-ESI--MS/MS method was successfully developed for the simultaneous detection of the eleven major active ingredients with different chemical structures in Tanreqing injection, and can be used for the quality control of Tanreqing injection as well.

Comparison of plasma pharmacokinetics of Tanreqing solution between intratracheal aerosolization and intravenous injection in rats.

A rapid ultra high performance liquid chromatography tandem mass spectrometry method was developed for the simultaneous analysis of baicalin, oroxylin A-7-O-ß-d-glucoronide and chlorogenic acid in rats plasma, and applied to comparison of pharmacokinetics of Tanreqing solution between intratracheal aerosolization and intravenous injection. Results of the analytical method validation assay showed high sensitivity, accuracy and suitable recovery. Results of pharmacokinetics showed similar decline phases for baicalin, oroxylin A-7-O-ß-d-glucoronide and chlorogenic acid in two different delivery routes. The half-lives of intratracheal aerosolization and intravenous injection were 0.90 and 1.22 h for baicalin, 0.47 and 0.17 h for oroxylin A-7-O-ß-d-glucoronide and 0.22 and 0.13 h for chlorogenic acid, and this implies that compounds were retained in the lung for a relatively short time. This study was the first to provide important pharmacokinetics information for traditional Chinese medicine delivery to the lung.

Self-Assembled Thermoresponsive Nanogels Prepared by Reverse Micelle → Positive Micelle Method for Ophthalmic Delivery of Muscone, a Poorly Water-Soluble Drug.

This study aimed to design a nanocarrier ophthalmic delivery system of muscone, a poorly water-soluble drug. The muscone thermoresponsive nanogels were self-assembled by reverse micelle → positive micelle method. Muscone was demonstrated to have uniform narrow particle size distribution in nanogel by the dynamic light scattering test. The developed nanocomposite hydrogel had a high muscone loading, and the rheology results showed that the phase transition temperature was 34.05°C. Thixotropy test indicated that the nanogel was able to resist the blinking of eyes because of the thixotropy recovery time, which is <5 s. Compared with muscone eye drops, muscone nanogels showed longer retention time on the corneal surface using fluorescent labeling technology and produced a 3.4-fold increase in apparent permeability coefficients (Papp). Draize testing showed that the developed nanogel caused no eye irritation. In vivo pharmacokinetic study indicated that the nanogel could significantly increase the bioavailability of muscone after administration compared with eye drops. These results indicate that self-assembled thermoresponsive nanogel prepared by reverse micelle → positive micelle method has potential for the ophthalmic delivery of poorly water-soluble drugs.

[Preparation and evaluation of Shedan in situ forming gel based on ocular characteristics].

To develop an ophthalmic preparation of Shedan, an in situ forming gel was prepared with the formulation containing 18% of poloxamer 407 and 5% of poloxamer 188 by response surface designs plus central composite designs. The rheology results showed that LVE range gamma should limited within 0.5%, Shedan high-frequency region, and the thixotropy recovery time is less than 5 seconds. The phase transition temperature was 33.25 °C according to curve of storage modulus and loss modulus determined by temperature scanning. Surface tension and osmometer of it determined by surface tension meter and dew point osmometer were 36.43 mN · m(-1), and 320.6 mOsm · kg(-1), respectively. Fluorescein sodium was selected as the marker to monitor the corneal residence time, and the results showed that Shedan gel could prolong drug residence for 180 min. In line with zero-order kinetics, releases of muscone and salvianolic acid B in vitro depends on gels erosion. The results of rabbit ocular irritation experiments suggested that Shedan in situ forming gel was biocompatible and nonirritant. In conclusion, a novel Shedan in situ forming gel was developed and characterized for potential drug treatment of retinal vein occlusion.

[Preparation and characterization of non-ionic surfactant vesicle of cantharidin].

OBJECTIVE: To study the preparation of cantharidin entrapped non-ionic surfactant vesicle (noisome)and evaluate its quality. METHOD: The niosome loaded with cantharidin was prepared using injection method by non-ionic surfactants as the carrier. An centrifugation separation method and HPLC analysis method of the cantharidin were established to detect the entrapment efficiency. The optimum preparation technology was established by a orthogonal experiment. The morphology, and particle size were studied to evaluate the preparation. RESULT: The average size of niosomes were (209. 8 +/- 0.5) nm. The entrapment efficiency of the CTD-NS was (27.5% +/- 2.0%) and Zeta potential was (41.5 +/- 0.65) mV. CONCLUSION: The preparation of cantharidin noisome by TweenA and SpanB is practicable and successful. These experiments can be the basement of developing targeting drug delivery system.

[Development of Silymarin nanocrystals lyophilized power applying nanosuspension technology].

OBJECTIVE: To prepare silymarin nanosuspension and lyophilized power for enhancing the dissilution of poorly soluble drugs. METHOD: The precipitation technique was adapted to produce the silymarin nanosuspensions respectivly applying Tween 80, SDS and Poloxamer188 as stabilizers. The lyophilized formula contained 5% mannitol as cryoprotectant. Particle size, Polydispersity index and Zeta potential were detected by Mastersizer nano ZS (Malvern England). Morphological character was observed with Transmission Electron Microscopy. The product's structure was performed with X-ray diffractometer. RESULT: The silymarin nanosuspension was successfully prepared, in which the drug particle size was about 100-300 nm,and the particles had ball-like shape and good dispersive properties. CONCLUSION: This study provided potential for the neotype dosage form development of the Chinese Traditional Medicine.

[Optimal extraction of nuciferine and flavone from lotus leaf based on central composite design and response surface methodology].

OBJECTIVE: To optimize the process of extracting effective constituents from lotus leaf. METHOD: Independent variables were ethanol concentration reflux time and solvent fold, dependent variables were extraction rates of nuciferine and flavone in lotus leaf, central composite design and response surface methodology were used for optimization of extraction of lotus leaf. RESULT: The optimum conditions of extraction process were 75% -80% ethanol, 2-3 hours for reflux, 20-25 fold solvent and 2 times for extraction. Bias between observed and predicted of rates of nuciferine and flavone values were 5.53%, -6.02%, respectively. CONCLUSION: The values observed and predicted were close to each other, which proved that the optimization of of extraction of lotus leaf by central composite design and response surface methodology was reasonable and successful.

[Comparative study on in vitro drug-release between Tuizhang ophthalmic gel and Tuizhang oculentum].

OBJECTIVE: To prepare tuizhang gel to cure cataract, the characteristics of Tuizhang gel on the drug-releasing in vitro were evaluated by compared with Tuizhang oculentum. METHOD: The emodin and chrysophanol in the releasing mediator were determined by HPLC, and the drug releasing characteristics of Tuizhang gel and Tuizhang oculentum were studied by bag filter method. RESULT: The emodin and chrysophanol in Tuizhang gel released (98.3, 1.1)%, (95.8, 1.8)% within 24 hours, respectively, while those in tuizhang oculentum released (10.62, 0.7)%, (10.46, 0.4)%, respectively. The emodin and chrysophanol in Tuizhang gel released more quickly and completely than in Tuizhang oculentum, so Tuizhang gel has enhanced the bioavailability. CONCLUSION: The Tuizhang gel is characterized by slow-release to some degree, and it shows a promising future on ophthalmic drug delivery.

[Studies on preparation technology of Flos Magnoliae essential oil-beta-cyclodextrin inclusion complex].

OBJECTIVE: To find the best condition of the preparation technology of Flos Magnoliae essential oil-beta-cyclodextrin inclusion complex. METHOD: L9(3(4)) table was used to examine the effects of 4 factors, and the inclusion rate of each test was determined of orthogonal test. RESULT: The best condition was:oil:beta-cyclodextrin:water = 1:8:60 (mL:g:mL), stirring for 1 hour at 80 degrees C. CONCLUSION: The complex prepared on the condition aforementioned is stable and stirring has a highest inclusion rate.

[Comparative studies on isolation and purification of Chinese medicine decoction].

OBJECTIVE: To evaluate different methods by treating water-decocted liquid of 6 Chinese medical herbs and 4 co-prescription respectively with alcohol, ultrafilter, macroporousresin and clarifier. METHOD: The contents of target component in those extracts were determined with HPLC or titration, and quantitative and qualitative determination of the impurity components, such as polysaccharide and protein, was made. RESULT: Each method showed its advantages and disavantages. CONCLUSION: Different method can be chosen according to the clinical and preparation demands or the characteristic of components.