Sustained Release of Minocycline From Minocycline-Calcium-Dextran Sulfate Complex Microparticles for Periodontitis Treatment

It is important to address the periodontitis-associated bacteria in the residual subgingival plaque after scaling and root planing to successfully treat periodontitis. In this study, we explored the possibility of exploiting the ion pairing/complexation of minocycline, Ca²⁺, and sulfate/sulfonate-bearing biopolymers to develop an intrapocket delivery system of minocycline as an adjunct to scaling and root planing. Minocycline-calcium-dextran sulfate complex microparticles were synthesized from minocycline, CaCl₂, and dextran sulfate. They were characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. An in vitro release study was conducted to evaluate the release kinetics of minocycline from these microparticles. Agar disk diffusion assays and biofilm-grown bacteria assays were used to assess antibacterial capability. High loading efficiency (96.98% ± 0.12%) and high loading content (44.69% ± 0.03%) for minocycline were observed for these complex microparticles. Mino-Ca-DS microparticles achieved sustained release of minocycline for at least 9 days at pH 7.4 and 18 days at pH 6.4 in phosphate-buffered saline, respectively. They also demonstrated potent antimicrobial effects against Streptococcus mutans and Aggregatibacter actinomycetemcomitans in agar disk diffusion and biofilm assays. These results suggested that the ion pairing/complexation of minocycline, Ca²⁺, and sulfonate/sulfate-bearing biopolymers can be exploited to develop complex microparticles as local delivery systems for periodontitis treatment.     

基于苯硼酸双羟基识别的竞争反应对黄芪甲苷的特异性检测研究

目的创新性地提出一种可高灵敏、高选择性定量检测中药材中黄芪甲苷的新方法。方法将氨基苯硼酸共价吸附到多孔硅胶中,制备得到苯硼酸功能化的分子印迹材料。该印迹材料中的双羟基基团能与黄芪甲苷分子结构中的双羟基发生特异性识别。采用紫外分光光度法为检测手段,以茜素红（ARS）为光度指示剂,利用ARS与黄芪甲苷之间的双羟基竞争反应,观察加入不同浓度的黄芪甲苷后所引起可见光区吸光度的变化,达到高灵敏定量分析黄芪甲苷的目的。结果在510 nm处,溶液吸光度响应值的变化与黄芪甲苷的浓度在1×10^-6-6.4×10^-4mol/L内呈现良好的线性关系,线性回归系数为0.9929,检出限为0.3×10^-6 mol/L。结论本方法结果可信,重复性较好,可用于中药材中黄芪甲苷的定量分析。     

塞克硝唑阴道泡腾片的处方工艺研究

目的研制塞克硝唑阴道泡腾片并初步建立含量测定方法。方法采用正交设计法进行试验,以崩解时间、发泡效果和pH值为指标综合评分筛选处方。用紫外分光光度法测定制剂的含量。结果最佳处方为A3B1C1,即硼酸、酒石酸、碳酸氢钠用量分别占片重的7.5%、22.5%、30%。紫外分光光度法测定塞克硝唑含量,在5.0~25.0μg.mL-1线性良好,平均回收率为98.4%,RSD为1.2%。结论塞克硝唑阴道泡腾片的制备工艺方便、科学,建立的含量测定方法简便、可靠。     

Validated liquid chromatographic method and analysis of content of tilianin on several extracts obtained from Agastache mexicana and its correlation with vasorelaxant effect

Ethnopharmacological relevance

To optimize the obtention of tilianin, an antihypertensive flavonoid isolated from Agastache mexicana (Lamiaceae), a medicinal plant used in Mexico for the treatment of hypertension. Also, a validated HPLC method to quantify tilianin from different extracts, obtained by several extraction methods, was developed.

Materials and methods

The aerial parts of Agastache mexicana were dried at different temperatures (22, 40, 50, 90, 100 and 180 °C) and the dry material was extracted with methanol by maceration to compare the content of the active constituent tilianin in the samples. Furthermore, EtOH:H₂O (7:3), infusion and decoction extracts were prepared from air-dried samples at room temperature to compare the content and composition of the different extraction methods. Moreover, an ex vivo vasorelaxant test on endothelium-intact aortic rat rings was conducted, in order to correlate the presence of tilianin with the activity of each extract.

Results

Higher concentration and amounts of tilianin were determined from chromatograms in the obtained methanolic extracts from plant material dried at 90, 50, 40 and 22 °C, followed by 100 °C; however, lower concentrations were observed in dried at 180 °C and EtOH:H₂O (7:3). It is worth to notice that methanolic extracts with higher amount of tilianin were the most potent vasorelaxant extracts, even though these extracts were less potent than carbachol, a positive control used. Finally, decoction, infusion and EtOH:H₂O (7:3) extracts did not show any vasorelaxant effect.

Conclusion

Results suggest that extracts with higher concentration of tilianin possess the best vasorelaxant activity, which allowed us to have a HPLC method for future quality control for this medicinal plant.     

Interactions of human serum albumin with retinoic acid, retinal and retinyl acetate

Human serum albumin (HSA), a major plasma protein and plasma-derived therapeutic, interacts with a wide variety of drugs and native plasma metabolites. In this study the interactions between HSA and small lipophilic molecules all-trans retinoic acid (RA), all-trans retinaldehyde (retinal, RAL) and all-trans retinyl acetate (RAC) were investigated by UV-vis absorption spectroscopy, fluorescence spectroscopy and circular dichroism (CD). This paper focuses on investigation of the interactions between HSA and RA by the visible CD. RAL and RAC were used in this study due to their structural identity to RA to elucidate the importance of the end functional group for the complex formation. Our data demonstrate that RA specifically binds to HSA in a stable non-covalent complex at least at two internal binding sites with close but distinct affinities. Upon titration of HSA with RA, visible CD spectra clearly demonstrate the appearance of a well-defined induced positive Cotton Effect (CE) around 350 nm. Beyond ligand-to-protein ratio of 0.8 and up to saturation (2.0), CD exhibits two major bands of opposite signs, suggesting exciton coupling between the chromophore molecules in the protein interior. The fluorescence quenching data suggest proximity of the primary RA binding site to tryptophan (W214). RAC shows a weak association with HSA with stoichiometry close to that of RA, while interactions of RAL with HSA proceed non-specifically at multiple sites. Contrary to RA, the adducts of HSA with RAC and RAL do not show any induced chirality, thus indicating that despite their high structural similarity to RA, both compounds do not appear to occupy the internal binding sites, but associate with the protein exterior.     

黄芪叶中有效成分含量的研究

目的：研究膜荚黄芪叶中皂苷、黄酮、多糖的含量。方法：采用连续回流提取法和超声波提取法提取膜荚黄芪叶中的皂苷、黄酮、多糖类成分,比色法测定其含量。结果：黄芪叶中黄酮和皂苷的含量较高。     

不同产地及不同采收期北柴胡中柴胡总皂苷的含量测定

目的:测定不同产地及不同采收期北柴胡中柴胡总皂苷的含量。方法:以柴胡皂苷a为对照品,采用紫外可见分光光度法,于535nm处测定不同产地及同一产地不同采收期北柴胡样品中柴胡总皂苷的含量。结果:柴胡总皂苷在0.0306～0.3062 mg具有良好的线性关系(r=0.9996),加样回收率为101.44%,RSD为3.29%,不同产地北柴胡中柴胡总皂苷含量为0.98%～2.05%;生长年限为19个月(9月28号采集)的河南嵩县北柴胡柴胡总皂苷含量达到最大富集值,为1.78%。结论:不同产地及同一产地不同采收期的北柴胡药材中的总皂苷含量存在明显差异,河南嵩县北柴胡的最佳采收期为生长周期第二年的9月28号。     

米非司酮壳型阴道环的制备方法及体外释放度研究

 目的研制米非司酮壳型阴道环，并考察其体外释放度。方法首先将药物制备成以PVP_K-30为载体的固体分散体，采用差式扫描量热法和X-射线衍射法进行表征。然后以硅橡胶为载体，采用热压硫化法制备米非司酮壳型阴道环，环内层为空白硅橡胶骨架，中间为含药部分，最外层为无活性的硅橡胶薄膜。以200mL（pH4.0）磷酸盐缓冲液为释放介质，采用紫外-可见分光光度法考察米非司酮阴壳型道环的体外释放度。结果米非司酮壳型阴道环释药更为平稳，每日平均释放药物1mg，持续释放时间至少达21d，且批间差异小。结论采用米非司酮固体分散体制备的壳型阴道环具有良好的缓控释特性，制备工艺稳定。采用紫外-可见分光光度法考察阴道环的体外释放度更方便、快速和准确。     

大孔吸附树脂分离纯化黄芪总皂苷的研究

目的：研究黄芪总皂苷的纯化方法。方法：黄芪水提醇沉的浓缩液，通过经处理的D101大孔吸附树脂，用不同浓度的乙醇进行梯度洗脱，UV法跟踪检测。结果：70％乙醇洗液中黄芪总皂苷的含量最高，可达到70％以上。结论：D101大孔吸附树脂可有效地分离提纯黄芪总皂苷。     

洁阴洗剂的制备及质量控制

目的：制备洁阴洗剂并进行质量控制。方法：以水煎提取法制备洁阴洗剂,以薄层色谱法进行定性鉴别,采用紫外可见分光光度法测定制剂中的总黄酮含量。结果：薄层色谱斑点清晰,阴性样品无干扰。紫外可见分光光度法测定波长为506nm,线性良好。稳定性试验表明,本制剂稳定性好。结论：该制剂制备工艺简单,质量稳定。本制剂的质量控制方法操作简便可行,能更好地控制该制剂的质量。