Effect of phenformin hydrochloride on pharmacokinetics of puerarin in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of phenformin hydrochloride that may be illegally added in traditional Chinese medicine preparations on the pharmacokinetics of puerarin in rats.</p><p><b>METHOD</b>Rats were randomly divided into the single pueraria group and the phenformin hydrochloride combined with pueraria group. After oral administration in the two groups, their bloods were sampled at different time points to determine the drug concentration of puerarin in rat blood and calculate pharmacokinetic parameters.</p><p><b>RESULT</b>After oral administration with pueraria extracts and phenformin hydrochloride combined with pueraria extracts, the two groups showed main pharmacokinetic parameters as follows: Cmax were (2.39 +/- 1.01), (1.03 +/- 0.35) mg x L(-1), respectively; Tmax were (0.50 +/- 0.09), (1.5 +/- 0.5) h, respectively; Ke were (0.153 +/- 0.028), (0.172 +/- 0.042) h(-1), respectively; t(1/2) were (4.65 +/- 0.86), (4.20 +/- 0.81) h, respectively; AUC(0-t), were (5.73 +/- 2.60), (5.45 +/- 1.81) mg x h x L(-1), respectively; AUC(0-infinity) were (6.72 +/- 2.89), (6.26 +/- 1.88) mg x h x L(-1), respectively. Compared with the single puerarin group, the Cmax was significantly decreased (P < 0.05) and the Tmax was markedly longer (P < 0.01) than the hydrochloride combined with pueraria group.</p><p><b>CONCLUSION</b>Phenformin hydrochloride can slow down the absorption process of puerarin and change the pharmacokinetic process of puerarin to some extent.</p>

LC-MS/MS method for quantification and pharmacokinetic study of gabapentin in human plasma / 药学学报

A sensitive, rapid and specific liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for quantification of gabapentin in human plasma has been developed. After a single plasma protein precipitation with methanol, gabapentin and metformin (internal standard) were chromatographed on a Inertsil ODS-3 column (50 mm x 2.1 mm ID, 3 microm) with mobile phase consisting of methanol-0.2% formic acid aqueous solution (80:20, v/v) at a flow-rate of 0.2 mL x min(-1). Electrospray ionization (ESI) source was applied and operated in the positive ion mode. Multiple reaction monitoring (MRM) mode with the transitions of m/z 172 --> m/z 154 and m/z 130 --> m/z 71 were used to quantify gabapentin and metformin, respectively. The run time was 2.2 min. The linear calibration curve was obtained in the concentration range of 40.8-8.16x10(3) ng x mL(-1). The lower limit of quantification was 40.8 ng x mL(-1). The intra- and inter-day precision (RSD) was less than 12%, and the accuracy (RE) was within +/-6.4% calculated from quality control (QC) samples. The method was used to determine the concentration of gabapentin in human plasma after a single oral administration of 600 mg gabapentin capsule to 20 healthy male Chinese volunteers. The method was proved to be selective, sensitive, rapid and suitable for pharmacokinetic study of gabapentin in human plasma.

Investigation on the chemical constituents and variation of the flower buds of Lonicera species by UPLC-ESI-MS/MS and principle component analysis / 药学学报

A rapid ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometric (UPLC-ESI-MS/MS) method is developed for the qualitative identification of constituents in the flower buds of seven Lonicera species. The optimal condition of separation and detection were achieved on an AcQuity UPLC BEH C18 column with a gradient elution with acetonitrile and 0.1% acetic acid within 17 min. Among the 33 constituents detected, 6 caffeoylquinic acids (including caffeic acid), 8 flavonoids and 8 iridoid glycosides were characterized based on their fragmentation patterns in collision-induced dissociation (CID) experiments and/or by comparison with standard compounds. In addition, to statistically establish the correlation and discrimination of the Lonicera species, principle component analysis (PCA) was applied in this study. Lonicera samples were divided into well-defined groups directly related to their species based on PCA in terms of the log transformed relative contents of the major caffeoylquinic acids (including caffeic acid) as the variables. All of results indicated that the method presented here is able to classify the sample species and to reveal characteristic details of the chemical constituents of different Lonicera species.

Determination of mosapride in human plasma by high performance liquid chromatography tandem mass spectrometry / 药学学报

To develop a sensitive and specific high performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method for the determination of mosapride in human plasma, mosapride and internal standard tamsulosin were extracted from plasma with liquid-liquid extraction, then separated on a Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm ID) with gradient elution at flow-rate of 0.25 mL x min(-1). The mobile phase was water (containing 0.3% formic acid) and acetonitrile under gradient conditions. Electrospray ionization (ESI) source was applied and operated in the positive ion mode. Multiple reaction monitoring (MRM) mode with the transitions of m/z 422 --> m/z 198 and m/z 409 --> m/z 228 were used to quantify mosapride and the internal standard, respectively. The linear calibration curve was obtained in the concentration range of 0.17 - 68.00 ng x mL(-1). The lower limit of quantification was 0.17 ng x mL(-1). The inter- and intra-day precision (RSD) was less than 13%, and the accuracy (RE) was within +/- 6.3% calculated from QC samples. The method was used to determine the concentration of mosapride in plasma after a single oral dose of 5 mg mosapride citrate to 20 healthy male Chinese volunteers. The method has been proved to be selective, sensitive, rapid and suitable for pharmacokinetic study of mosapride.

Fingerprint analysis of composite Folii Isatidis injection by HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>To develop the chromatographic fingerprints of composite Folii Isatidis injection by HPLC.</p><p><b>METHOD</b>The separation was performed on a Diamonsil C18 column with a mobile phase consisting of methanol-water-phosphoric acid as gradient eluent at the flow rate of 1.0 mL x min(-1). The UV detection was set at 254 nm.</p><p><b>RESULT</b>A standard HPLC fingerprint procedure was developed for composite Folii Isatidis injection, with 20 common peaks and a similarity threshold of 9.0 established.</p><p><b>CONCLUSION</b>This method was accurate, repeatable and useful for the quality control of composite Folii Isatidis injection.</p>

Chemical constituents from herb of Epimedium brevicornum / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the chemical constituents of Epimedium brevicornum.</p><p><b>METHOD</b>The chemical constituents were isolated by using silica gel column chromatography and preparative TLC. The structures were identified on the basis of physical-chemical constants and spectral data.</p><p><b>RESULT</b>Five compounds were isolated and identified as hyperoside, icariin, epimedin B, epimedin C, inositol.</p><p><b>CONCLUSION</b>Compound I and III - V were isolated from the plant for the first time.</p>

Liquid chromatography frontal analysis of the protein binding of glimepiride / 药学学报

<p><b>AIM</b>To study the protein binding of glimepiride.</p><p><b>METHODS</b>An HPLC-FA method is performed by using Pinkerton GFF II-S5-80 internal-surface reversed-phase silica support (150 mm x 4.6 mm ID, 5 microm) at pH 7.4 in a 67 mmol x L(-1) isotonic sodium phosphate buffer at 37 degree C. Other conditions included flow rate of 0.2 mL x min(-1), UV detection at wavelength 230 nm and injection volume 900 microL.</p><p><b>RESULTS</b>Nonlinear regression parameter estimation was used for the association constant measurement of glimepiride to both primary and secondary sites, which were 5.1 (micromol x L(-1)-1 and 1 for K1 and n1, and 0.017 (micromol x L(-1))-1 and 7 for K2 and n2, respectively.</p><p><b>CONCLUSION</b>The method is shown to be suitable for investigation of protein binding of glimepiride.</p>

Determination of adenosine, rutin and quercetin in Carthamus tinctorius by HPCE / 药学学报

<p><b>AIM</b>To develop a method for determination of adenosine, rutin and quercetin in Carthamus tinctorius L. by high performance capillary electrophoresis(HPCE).</p><p><b>METHODS</b>A fused silica capillary (66.5 cm x 50 microns ID, an effective length of 58 cm) was used. The running buffer composed of 50 mmol.L-1 borax (pH 9.7) containing 18% methanol. The applied voltage was 24 kV and the capillary temperature was 20 degrees C. The detection wavelength was 210 nm. Rifampicin was used as internal standard.</p><p><b>RESULTS</b>A good linearity between peak area ratio of the common peak to the internal standard and the concentration was found in the range of 10-160 mg.L-1 for adenosine, 100-2,000 mg.L-1 for rutin and 100-1,600 mg.L-1 for quercetin (r > 0.998). The average recoveries were 98.5%-100.5%, 96.9%-99.5% and 99.1%-99.5% for adenosine, rutin and quercetin, respectively. The relative standard deviation was less than 6.5% (n = 5).</p><p><b>CONCLUSION</b>The method is simple, rapid and with satisfactory recoveries and good reproducibilities. It can be used to control the quality of Carthamus tinctorius.</p>

Preparation and simultaneous determination of corynoline and acetylcorynoline in the herb of Corydalis bungeana / 中国中药杂志

<p><b>OBJECTIVE</b>To isolate and purify corynoline and acetylcorynoline from Corydalis bungeana and develop a reversed-phase HPLC method of determining the two components in C. bungeana.</p><p><b>METHOD</b>Alkaloids were isolated from the ethanolic extract with column gel chromatography, and identified on the basis of spectral analysis (UV, 1H-NMR, 13C-NMR) and physicochemical properties. For quantitative analysis of the two components, samples were separated on an ODS column with mobile phase of methanol-15 mmol.L-1 potassium dihydrogen phosphate/potassium phosphate dibasic (pH 6.70, 70:30). The flow rate was 0.8 mL.min-1, and the detection was set at 289 nm.</p><p><b>RESULT</b>The purity was 99.5% and 99.1% for corynoline and acetylcorynoline respectively. The calibration curves were linear in the range of 6.9-110.4 mg.L-1 corynoline and 8.7-139.5 mg.L-1 acetylcorynoline. The RSD was 2.1% and 2.7%, and the average recovery was 97.3% and 97.2% respectively.</p><p><b>CONCLUSION</b>The method of isolating and purifying corynoline and acetylcorynoline from Corydalis bungeana and the HPLC method of simultaneous determination of the two components have been developed. The HPLC method is simple, easy to perform and applicable to the content determination of corynoline and acetylcorynoline in C. bungeana of various origins.</p>

Determination of trigonelline in Trigonella foenum-graecum by HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>A HPLC method is established to determine the content of trigonelline in Trigonella foenum-graecum.</p><p><b>METHOD</b>The medicinal material was extracted by petholeum ether-ethanol. Asahipak NH2P-50 column was used, mobilephase consisted of acetonitrile-water(75:25) and detection wavelength was set at UV 265 nm.</p><p><b>RESULT</b>The standard curve was linear in the range of 3.68-73.60 micrograms.mL-1 with the correlation coefficient of 0.9999. The average recovery rate and RSD were 97.4% and 1.83% (n = 6) respectively.</p><p><b>CONCLUSION</b>It provides scientific indexes for quality control of T. foenum-graecum.</p>

HPLC determination of two flavonoid compounds in Psoralea corylifolia / 中国中药杂志

<p><b>OBJECTIVE</b>To determine two flavonoid compounds in Psoralea corylifolia L. (PC) simultaneously with HPLC method.</p><p><b>METHOD</b>Bavachin and corylin isolated from PC and purified in our laboratory were used as the reference compounds. The HPLC separation was carried out on an Techsphere ODS column using mobile phase consisting of a mixture of methanol and 20 mmol.L-1 ammonium acetate buffer pH 4.0 (67:33), and the UV detection wavelength was 240 nm.</p><p><b>RESULT</b>Simultaneous determination of bavachin and corylin was achieved. The linear range was 1.25-20 micrograms.mL-1 for both bavachin and corylin. The average recovery of bavachin and corylin was 94.9% and 96.2%, and RSD was 3.1% and 3.6% respectively.</p><p><b>CONCLUSION</b>This is the first report on simultaneous determination of bavachin and corylin in PC with satisfactory accuracy and reproducibility.</p>