Objective To assess the rationality about traditional preliminary processing and discuss the factors that affect the quality of Glehnia littoralis via the removal of the root bark.Methods According to the literature and our recent findings,the amounts of the active components and the impurity were summarized after the root bark removed.Results and Conclusions The removal of the root bark could improve the appearance quality,meanwhile decrease the amounts of some active components,indicating that the root bark deserves to be further exploited.

Objective To establish an ion-pair RP-HPLC method for the determination of the contents of α-ketoleucine calcium and its related substances.Methods The determination of α-ketoleucine calcium and the separation of its related substances were performed on a C18 column(250 mm×4.6 mm,5 μm).The mobile phase was acetonitrile-0.05%(w)potassium dihydrogen phosphae(pH2.5)(V∶V=23∶67)with 0.01%(w)tetrabutyl ammonium hydroxide.The flow rate was 1.0 mL·min-1.Ultraviolet absorption detector was set at 220 nm with column temperature at 30 ℃.Results The linear range of α-ketoleucine calcium was between 40 and 160 mg·L-1(r=0.999 7).The average recovery was 100.4%(w)with RSD of 0.7%.The related substances of α-ketoleucine calcium could be completely separated from α-ketoleucine calcium.The limit of detection(LOD)was 16 ng.Conclusion The method is simple and accurate for quality control of the α-ketoleucine calcium.

Objective To isolate and identify the chemical constituents from the roots of Glehnia littoralis.Methods The compounds were separated by chromatography on silica gel,TLC,Sephadex LH-20 and reverse phase ODS.The structures of the isolated compounds were elucidated based on spectroscopic data and chemical properties.Results Nine compounds were isolated from G.littoralis.Their structures were identified as 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxyl-1-(E)-propenyl)-2-methoxyphenoxy]propyl-β-D-gucopyranoside(1),2,3-E-2,3-dihydro-2-(3′-methoxy-4′-hydroxyphenyl)-3-hydroxymethyl-5-(3″-hydroxypropeyl)-7-O-β-D-glucopyranosyl-1-benzo[b]furan(2),protocatechuic acid methyl ester(3),esculetin(4),glehlinoside J(5),scopolin(6),sec-O-glucosylhamaudol(7),(-)-secoisolariciresinol 4-O-β-D-glucopyranoside(8),glehlinoside C(9).Conclusions Compound 1-4 and 6-7 are isolated from this genus for the first time.

Carbamazepine (CBZ)–hydroxypropyl-β-cyclodextrin (HP-β-CD) complex in the presence of HPMC was prepared and characterized by differential scanning calorimetry (DSC) and X-ray diffractometer intended for improving the dissolution rate of CBZ. The phase-solubility method was used to investigate the effect of HP-β-CD and HPMC on the solubility of CBZ. Tablets of the resulting complex were prepared using direct compression method and the bioavailability was evaluated in beagle dogs using a UPLC/MS/MS method. The results showed solubility of CBZ was increased up to 95 times by complexation with HP-β-CD in the presence of 0.1% HPMC. The results of DSC and X-ray diffraction proved a formation of complex between CBZ and HP-β-CD. Dissolution rate of CBZ was notably improved from complex tablets with more than 97.39% released within 10 min; whereas for the commercial tablets, around 60% was released within 30 min. Using commercial tablets as the reference formulation, the bioavailability of complex tablets was considerably increased by 1.5-fold (P < 0.05) and Tmax was reduced to 0.88 h compared with 1.25 h for commercial tablets. Furthermore, a lower inter-subject variability (49.9%) was observed compared with that of the commercial tablets (39.7%). It is evident from the results herein that complexation with HP-β-CD in the presence of HPMC is a feasible way to prepare a rapidly acting and better absorbed CBZ oral product.