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1.
This study was conducted to enhance dissolution rate of aceclofenac (ACF) with extremely low solubility and high permeability (BCS class II) in water using poly vinyl pyrrolidone (PVP) and sodium lauryl sulfate as carriers. Solid dispersions were prepared by spray drying method and rotary evaporation method using different ratios of ACF and polymers. The characterization of solid dispersions was evaluated by scanning electron microscopy, Fourier transformation infrared spectroscopy, differential scanning calorimetry and powder X-ray diffractometer. The dissolution behavior of solid dispersions was compared with pure ACF (API) and Airtal® (Deawoong, Co, Korea) as control groups in simulated phosphate buffer at pH 6.8. The dissolution rate of the drug was affected by nature and amount of polymer used. The prepared solid dispersion of ACF/PVP (1:5) appeared to have the highest dissolution rate. Therefore, solid dispersion techniques of spray drying and rotary evaporation method can be successfully used for the enhancement of the dissolution rate of ACF.  相似文献   

2.
The effect of adding a third polymer to immiscible binary solid dispersions was investigated. The model actives griseofulvin (GF), progesterone (PG) and phenindione (PD) were selected because they exemplify a key property of many poorly soluble molecules of having at least one hydrogen bonding acceptor moiety while not having any hydrogen bond donating moieties. Ternary solid dispersions of the drug, PVP (polyvinylpyrrolidone) (proton acceptor) and PHPMA (poly[2-hydroxypropyl methacrylate]) (proton acceptor and donor) were prepared by spray drying. Stability results showed that binary solid dispersions (API and PVP) of GF and PVP crystallized quickly while the amorphous form was not possible to prepare for PG and PD. The amorphous form was prolonged upon the incorporation of PHPMA in the solid dispersion (API, PHPMA and PVP). Based on measuring the melting points, the energy of mixing the drug with the polymer was calculated using the Flory-Huggins theory. The results showed that GF had the lowest free energy followed by PG and finally PD which agreed well with the stability results. These results suggest that the addition of a third polymer to immiscible binary solid dispersions can significantly improve the stability of the amorphous form.  相似文献   

3.
The objective of this study was to investigate the effect of different polymeric carriers in solid dispersions with an active pharmaceutical ingredient (API) on their water vapour sorption equilibria and the influence of the API–polymer interactions on the dissolution rate of the API. X-ray diffraction, scanning electron microscopy (SEM), moisture sorption analysis, infrared (IR) spectroscopy and dissolution tests were performed on various API–polymer systems (Valsartan as API with Soluplus, PVP and Eudragit polymers) after production of amorphous solid dispersions by spray drying. The interactions between the API and polymer molecules caused the water sorption isotherms of solid dispersions to deviate from those of ideal mixtures. The moisture sorption isotherms were lower in comparison with the isotherms of physical mixtures in all combinations with Soluplus and PVP. In contrast, the moisture sorption isotherms of solid dispersions containing Eudragit were significantly higher than the corresponding physical mixtures. The nature of the API–polymer interaction was explained by shifts in the characteristic bands of the IR spectra of the solid dispersions compared to the pure components. A correlation between the dissolution rate and the water sorption properties of the API–polymer systems has been established.  相似文献   

4.
难溶性药物由于溶解性和溶出度较低,限制了其在体内的吸收分布,进而影响药物发挥药效,是药学研究的热点之一。固体分散体可以提高难溶性药物溶解度,采用喷雾干燥技术制备固体分散体,由于其良好的干燥效率和工艺重现性,近年来备受关注。本文对喷雾干燥的工艺步骤、设备类型及制备固体分散体常用聚合物等作一综述,并分析讨论了影响固体分散体关键质量属性的因素,探讨了喷雾干燥技术应用生产的困难和挑战。  相似文献   

5.
Solid dispersions of a poorly water-soluble drug piroxicam in polyvinylpyrrolidone (PVP) were prepared by precipitation with compressed antisolvent (PCA) and spray drying techniques. Physicochemical properties of the products and drug-polymer interactions were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry, etc. Piroxicam was found amorphously dispersed in both solid dispersion systems with the drug to polymer weight ratio of 1:4. Spectra data indicated the formation of hydrogen bonding between the drug and the polymer. Both techniques evaluated in this work resulted in improved dissolution of piroxicam. By comparison, PCA-processed solid dispersions showed distinctly superior performance in that piroxicam dissolved completely within the first 5 min and the dissolution rate was at least 20 times faster than raw drug did within the first 15 min. PCA processing could provide an effective pharmaceutical formulation technology to improve the bioavailability of poorly water-soluble drug.  相似文献   

6.
艾秀娟  叶冠文 《中南药学》2010,8(6):425-428
目的制备盐酸溴己新(BH)固体分散体并研究其体外溶出度。方法以聚乙烯吡咯烷酮(PVP)为载体,采用喷雾干燥法制备难溶性药物盐酸溴己新固体分散体,并进行体外溶出实验。结果制备成的固体分散体能显著提高盐酸溴己新的体外溶出速率,PVPk-15载体的固体分散体溶出较PVPk-30载体的固体分散体快。随着PVPk-15载体比例增加,固体分散体的溶出先增大后减小,BH-PVPk-15为1∶5时的固体分散体具有良好的体外速释作用。结论将盐酸溴己新制成固体分散体能明显提高其溶解度及体外释放速率。  相似文献   

7.
Solid dispersions in water-soluble carriers have attracted considerable interest as a means of improving the dissolution rate, and hence possibly bioavailability, of a range of hydrophobic drugs. The aim of the present study was to improve the solubility and dissolution rate of a poorly water-soluble drug, Lovastatin, by a solid dispersion technique. Solid dispersions were prepared by using polyethylene glycol 4000 (PEG 4000) and polyvinylpyrrolidone K30 (PVP K30) in different drug-to-carrier ratios. Dispersions with PEG 4000 were prepared by fusion-cooling and solvent evaporation, whereas dispersions containing PVP K30 were prepared by solvent evaporation technique. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, X-ray powder diffraction, and FT-IR spectroscopy. The aqueous solubility of Lovastatin was favored by the presence of both polymers. The negative values of the Gibbs free energy and enthalpy of transfer explained the spontaneous transfer from pure water to the aqueous polymer environment. Solid-state characterization indicated Lovastatin was present as amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure Lovastatin, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. This can be attributed to improved wettability and dispersibility, as well as decrease of the crystalline and increase of the amorphous fraction of the drug. Solid dispersion prepared with PVP showed the highest improvement in wettability and dissolution rate of Lovastatin. Even physical mixture of Lovastatin prepared with both polymers also showed better dissolution profile than that of pure Lovastatin. Tablets containing solid dispersion prepared with PEG and PVP showed significant improvement in the release profile Lovastatin compared with tablets containing Lovastatin without PEG or PVP.  相似文献   

8.
Many small-molecule active pharmaceutical ingredients (APIs) exhibit low aqueous solubility and benefit from generation of amorphous dispersions of the API and polymer to improve their dissolution properties. Spray drying and hot-melt extrusion are 2 common methods to produce these dispersions; however, for some systems, these approaches may not be optimal, and it would be beneficial to have an alternative route. Herein, amorphous solid dispersions of compound A, a low-solubility weak acid, and copovidone were made by conventional spray drying and co-precipitation. The physicochemical properties of the 2 materials were assessed via X-ray diffraction, differential scanning calorimetry, thermal gravimetric analysis, and scanning electron microscopy. The amorphous dispersions were then formulated and tableted, and the performance was assessed in vivo and in vitro. In human dissolution studies, the co-precipitation tablets had slightly slower dissolution than the spray-dried dispersion, but both reached full release of compound A. In canine in vitro dissolution studies, the tablets showed comparable dissolution profiles. Finally, canine pharmacokinetic studies showed that the materials had comparable values for the area under the curve, bioavailability, and Cmax. Based on the summarized data, we conclude that for some APIs, co-precipitation is a viable alternative to spray drying to make solid amorphous dispersions while maintaining desirable physicochemical and biopharmaceutical characteristics.  相似文献   

9.
Cilostazol is practically insoluble in water and thus results in poor bioavailability. Only a few approaches have been reported for improving the bioavailability of cilostazol. Solid dispersion technique via solvent evaporation method was applied to improve the solubility and dissolution of cilostazol. Various polymers, mixture of polymer and surfactant, and mixture of polymers were screened as a carrier for the solid dispersion. Solubility of cilostazol was improved significantly when Eudragit® L100 was used as a carrier. However, addition of surfactant to Eudragit® L100 decreased the solubility slightly. Whereas, the mixture of Eudragit® L100 and Eudragit® S100 as a carrier system further increased the solubility. Based on the highest solubility obtained among the carriers screened, 1:1 ratio of Eudragit® L100 and Eudragit® S100 was selected as a carrier, and drug to carrier ratio was optimized to 1:5. Differential scanning calorimetry and X-ray diffraction studies showed that the characteristic peak of cilostazol disappeared in the solid dispersion, indicating that cilostazol existed in amorphous form in this formulation. Spray drying method was superior to vacuum drying method in terms of dissolution rate. Meanwhile, it was observed that the disintegration rate and the concentration of polymer had some effect on the crystallization of cilostazol in dissolution medium. Tablet formulation containing spray dried solid dispersion showed significant improvement in dissolution as compared to the commercial tablet.  相似文献   

10.
杨凌  钟延强 《药学实践杂志》2010,28(5):339-341,344
目的 制备尼莫地平固体分散体,增加其溶出速度.方法 应用聚乙烯吡咯烷酮(PVP)为载体,采用喷雾干燥制备尼莫地平固体分散体,通过差示扫描量热分析(DSC)和X-射线粉末衍射分析鉴别药物在载体中的存在状态,并进行了体外溶出度研究.结果 尼莫地平在载体中以分子状态存在,尼莫地平固体分散体的溶出度与尼莫地平原料药和原料药载体物理混合物相比有显著提高,载体比例越大,药物溶出越快,药物载体比例为1:3时t50仅0.972 6 min,结论聚乙烯吡咯烷酮(PVP)作为尼莫地平固体分散体的载体载药量大;喷雾干燥工艺重现性好,分散体颗粒无需粉碎可满足各类固体制剂的制备要求,是一种较理想的尼莫地平固体分散体的制备方法.  相似文献   

11.
To improve solubility of tadalafil (Td), a poorly soluble drug substance (3 μg/ml) belonging to the II class of the Biopharmaceutical Classification System, its six different solid dispersions (1:1, w/w) in the following polymers: HPMC, MC, PVP, PVP-VA, Kollicoat IR and Soluplus were successfully produced by freeze-drying. Scanning electron microscopy showed a morphological structure of solid dispersions typical of lyophilisates. Apparent solubility and intrinsic dissolution rate studies revealed the greatest, a 16-fold, increase in drug solubility (50 μg/ml) and a significant, 20-fold, dissolution rate enhancement for the Td/PVP-VA solid dispersion in comparison with crystalline Td. However, the longest duration of the supersaturation state in water (27 μg/ml) over 24 h was observed for the Td solid dispersion in HPMC. The improved dissolution of Td from Td/PVP-VA was confirmed in the standard dissolution test of capsules filled with solid dispersions. Powder X-ray diffraction and thermal analysis showed the amorphous nature of these binary systems and indicated the existence of dispersion at the molecular level and its supersaturated character, respectively. Nevertheless, as evidenced by film casting, the greatest ability to dissolve Td in polymer was determined for PVP-VA. The crystallization tendency of Td dispersed in Kollicoat IR could be explained by the low Tg (113 °C) of the solid dispersion and the highest difference in Hansen solubility parameters (6.8 MPa0.5) between Td and the polymer, although this relationship was not satisfied for the partially crystalline dispersion in PVP. Similarly, no correlation was found between the strength of hydrogen bonds investigated using infrared spectroscopy and the physical stability of solid dispersions or the level of supersaturation in aqueous solution.  相似文献   

12.
Objectives Andrographolide, a natural lipophilic molecule, has a wide range of pharmacological actions. However, due to low aqueous solubility, it has low oral bioavailability. The purpose of the study was to increase the solubility and dissolution rate of isolated andrographolide by formulating its solid dispersion. Method Solid dispersions were obtained by a spray‐drying technique using different ratios of drug to polyvinylpyrrolidine (PVP K‐30). Solid dispersions in compression with isolated drug and corresponding physical mixtures were characterized for various molecular pharmaceutical properties and subjected to stability study for up to 3 months. Key findings A five‐fold increase in saturation solubility of andrographolide with higher values of Q5min (cumulative percentage release in 5 min) and lower values of t75% (time required for 75% w/w drug release) for solid dispersion was observed in different dissolution mediums. This was attributed to the formation of amorphous nature and intermolecular hydrogen bonding between drug and PVP K‐30. The stability study showed there to be no significant change in molecular pharmaceutical properties and dissolution profile over the period of 3 months. Moreover, the in‐vivo study in Wistar albino rats also justified improvement in the therapeutic efficacy of andrographolide after solid dispersion. Conclusions This study demonstrates the utility of solid dispersion to improve primary and secondary pharmaceutical properties of andrographolide using PVP K‐30 as a carrier.  相似文献   

13.
目的:为了提高难溶性药物阿瑞匹坦(Aprepitant,APR)的溶解度,解决其酸中溶出、碱中结晶沉淀的问题,选择不同功能的聚合物载体,采用热熔挤出技术制备三元固体分散体,并对其进行性能考察;方法:采用溶剂-熔融法制备二元固体分散体,以溶出度和溶出速度为指标,筛选具有增溶功能的载体材料。通过介质转移法考察各聚合物在不同浓度的药物溶液中的抑晶性能,筛选出最佳的沉淀抑制剂。确定药载比,将APR、溶出促进剂及沉淀抑制剂以不同比例混合,采用热熔挤出技术制备三元固体分散体,以溶出度和抑晶时间为指标,优选出三元固体分散体处方。经XRD确认药物在载体中的存在状态,考察该三元固体分散体在模拟肠液中的动态溶解度和加速条件下的物理稳定性。结果:亲水性聚合物PVP K30制备的二元固体分散体溶出速度快,增溶效果佳,肠溶性聚合物HPMCAS显示出优越的抑晶作用,延长了APR的过饱和点,质量比为1:1:3(APR:PVP K30:HPMCAS)的三元固体分散体在酸中迅速完全释放(120min溶出95%),相对于原料药显著提高了溶出度和溶出速率,当介质pH转为6.8后,三元固体分散体完全释放并在6h内维持溶液处于高过饱和的稳定状态,药物以无定形形式存在于载体基质中,同时能在加速条件下保持至少三个月的无定形状态。结论:基于不同聚合物的理化特性,本研究制备的三元固体分散体通过协调溶出速率和结晶抑制效果,不仅显著提高APR的溶解度,并能解决APR在胃中溶出、肠中沉淀析晶的问题,具有良好的溶出特性。  相似文献   

14.
Amorphous solid dispersions are used as a strategy to improve the bioavailability of poorly water-soluble compounds. When formulating with a polymer, it is important not only for the polymer to stabilize against crystallization in the solid state, but also to improve the dissolution profile through inhibiting crystallization from the supersaturated solution generated by dissolution of the amorphous material. In this study, the dissolution profiles of solid dispersions of felodipine formulated with poly(vinylpyrrolidone) (PVP), hydroxypropyl methylcellulose (HPMC) or hydroxypropyl methylcellulose acetate succinate (HPMCAS) were compared. In addition, concentration versus time profiles were evaluated for the supersaturated solutions of felodipine in the presence and absence of the polymers. HPMCAS was found to maintain the highest level of supersaturation for the greatest length of time for both the dissolution and solution crystallization experiments, whereas PVP was found to be the least effective crystallization inhibitor. All polymers appeared to reduce the crystal growth rates of felodipine at an equivalent supersaturation and this mechanism most likely contributes to the enhanced solution concentration values observed during dissolution of the amorphous solid dispersions.  相似文献   

15.
Spray drying is an efficient technology for solid dispersion manufacturing since it allows extreme rapid solvent evaporation leading to fast transformation of an API-carrier solution to solid API-carrier particles. Solvent evaporation kinetics certainly contribute to formation of amorphous solid dispersions, but also other factors like the interplay between the API, carrier and solvent, the solution state of the API, formulation parameters (e.g. feed concentration or solvent type) and process parameters (e.g. drying gas flow rate or solution spray rate) will influence the final physical structure of the obtained solid dispersion particles. This review presents an overview of the interplay between manufacturing process, formulation parameters, physical structure, and performance of the solid dispersions with respect to stability and drug release characteristics.  相似文献   

16.
Solid dispersions were prepared by a melting method from the water-insoluble model drugs carbamazepine and nifedipine and polyethylene glycol 1500 (PEG 1500) or 1:1 mixtures of PEG 1500 and the polymers polyvinylpyrrolidone (PVP 30, PVP 12), polyvinylpyrrolidone-co-vinylacetate (PVPVA) and Eudragit EPO (Eudragit) in order to combine advantages of the different carrier polymers (recrystallization inhibition, processability and stability). The solid dispersions were characterized by dissolution, powder X-ray diffractometry and microscopy directly after preparation and after storage for 3 and 6 months at 25 °C/0% relative humidity (RH) or 3 months at 40 °C/75% RH. More than 80% drugs were released from all solid dispersions within 20 min. The dissolution rate of carbamazepine decreased in the order of PEG 1500 > PEG 1500/Eudragit > PEG 1500/PVP 30 > PEG 1500/PVPVA > PEG 1500/PVP 12. The dissolution rank order was not directly correlated to the amorphous/crystalline state of the drugs, but rather to the properties of the PEG 1500/polymer compositions. Nifedipine was released in the order of PEG 1500 > PEG 1500/PVPVA > PEG 1500/PVP 30 > PEG 1500/PVP 12 > PEG 1500/Eudragit. Amorphous nifedipine was present in all PEG 1500/polymer dispersions except in pure PEG 1500 solid dispersion. The significant increase in dissolution rate of PEG 1500 solid dispersions was due to the reduced crystallinity of the drug and the excellent solubilisation properties of PEG 1500. After 6 months storage at 25 °C/0% RH, the solid dispersions released both drugs in the order PEG 1500/PVPVA > PEG 1500/PVP 30 > PEG 1500/PVP 12 > PEG 1500/Eudragit > PEG 1500. The stabilized amorphous state of the drug resulted in stable dissolution profiles of PEG 1500/PVPVA, PEG 1500/PVP 30 and PEG 1500/PVP 12 when compared to the PEG 1500 solid dispersions, which contained a higher amount of crystalline drug. The solid dispersions with PEG 1500/PVPVA or PEG 1500/PVP stored for 3 months at 40 °C/75% RH showed phase separation due to the hygroscopic properties of the polymers. The influence of 10% (w/w) of the solubilisers polyoxyl 40 hydrogenated castor oil (Cremophor), macrogol-15-hydroxystearate (Solutol) and fatty alcohol alkoxylate (Pluronic) on the dissolution rate and the physical state of the drug was significant.  相似文献   

17.
In order to reduce the crystallinity of PEG 6000, blends were prepared by spray drying and extrusion with the following polymers; PVP K25, PVPVA 64, and HPMC 2910 E5. The maximal reduction of crystallinity in PEG 6000 was obtained by co-spray drying with HPMC 2910 E5. In the next step the model drug Itraconazole was added to the blend and the resulting ternary solid dispersions were characterized. The results of this study show that the addition of PEG 6000 to the Itraconazole/HPMC 2910 E5 system leads to phase separation that in most cases gives rise to recrystallization of either PEG 6000 or Itraconazole. For all ternary dispersions containing 20% of Itraconazole the drug was highly amorphous and the dissolution was improved compared to the binary 20/80 w/w Itraconazole/HPMC 2910 E5 solid dispersion. For all ternary dispersions containing 40% of Itraconazole, the drug was partially crystalline and the dissolution was lower than the dissolution of the binary 40/60 w/w Itraconazole/HPMC 2910 E5 dispersion. These results show that provided Itraconazole is highly amorphous the addition of PEG 6000 to HPMC 2910 E5 leads to an increase in drug release.  相似文献   

18.
The present study investigates the effect of changing spray drying temperature (40°C–120°C) and/or atomizing airflow rate (AR; 5–15 L/min) on the phase structure, physical stability, and performance of spray-dried naproxen–polyvinylpyrrolidone (PVP) K25 amorphous solid dispersions. The modulated differential scanning calorimetry, attenuated total internal reflectance-Fourier transform infrared, and powder X-ray diffractometry (pXRD) studies revealed that higher inlet temperature (IT) or atomization airflow leads to the formation of amorphous-phase-separated dispersions with higher strongly H-bonded and free PVP fractions, whereas that prepared with the lowest IT was more homogeneous. The dispersion prepared with the lowest atomization AR showed trace crystallinity. Upon exposure to 75% relative humidity (RH) for 3 weeks, the phase-separated dispersions generated by spray drying at higher temperature or higher atomization airflow retained relatively higher amorphous drug fraction compared with those prepared at slow evaporation conditions. The humidity-controlled pXRD analysis at 98% RH showed that the dispersion prepared with highest atomization AR displayed the slowest kinetics of recrystallization. The molecular-level changes occurring during recrystallization at 98% RH was elucidated by spectroscopic monitoring at the same humidity. The rate and extent of the drug dissolution was the highest for dispersions prepared at the highest atomizing AR and the lowest for that prepared with the slowest atomizing condition.  相似文献   

19.
Solid dispersions in water-soluble carriers have attracted considerable interest as a means of improving the dissolution rate, and hence possibly bioavailability, of a range of hydrophobic drugs. The aim of the present study was to improve the solubility and dissolution rate of a poorly water-soluble drug, Lovastatin, by a solid dispersion technique. Solid dispersions were prepared by using polyethylene glycol 4000 (PEG 4000) and polyvinylpyrrolidone K30 (PVP K30) in different drug-to‐carrier ratios. Dispersions with PEG 4000 were prepared by fusion-cooling and solvent evaporation, whereas dispersions containing PVP K30 were prepared by solvent evaporation technique. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, X-ray powder diffraction, and FT-IR spectroscopy. The aqueous solubility of Lovastatin was favored by the presence of both polymers. The negative values of the Gibbs free energy and enthalpy of transfer explained the spontaneous transfer from pure water to the aqueous polymer environment. Solid-state characterization indicated Lovastatin was present as amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure Lovastatin, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. This can be attributed to improved wettability and dispersibility, as well as decrease of the crystalline and increase of the amorphous fraction of the drug. Solid dispersion prepared with PVP showed the highest improvement in wettability and dissolution rate of Lovastatin. Even physical mixture of Lovastatin prepared with both polymers also showed better dissolution profile than that of pure Lovastatin. Tablets containing solid dispersion prepared with PEG and PVP showed significant improvement in the release profile of Lovastatin compared with tablets containing Lovastatin without PEG or PVP.  相似文献   

20.
Artemether (ARM) is a poorly water soluble and poorly permeable drug effective against acute and severe falciparum malaria, hence there is a strong need to improve its solubility. The objective of the study was to enhance the solubility and dissolution rate of ARM by preparation of solid dispersions using spray-drying technique. Solid dispersions of ARM were prepared with Soluplus, Kollidon VA 64, HPMC and Eudragit EPO at weight ratios of 1:1, 1:2, 1:3 using spray drying technology, and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and X-ray powder diffraction (XRD) to identify the physicochemical interaction between drug and carrier, as well as effect on dissolution. The prepared solid dispersion of ARM with polymers showed reduced crystallinity as compared to neat ARM, which was confirmed by DSC and XRD. Drug/polymer interactions were studied in-silico by docking and molecular dynamics which indicated formation of van der Waals type of interactions of ARM with the polymers. Based on solubility studies, the optimum drug/Soluplus ratio was found to be 1:3. The dissolution studies of formulation SD3 showed highest drug release up to 82% compared to neat ARM giving only 20% at 60 minutes. The spray-dried products were free of crystalline ARM; possessed higher dissolution rates, and were stable over a period according to ICH guidelines. These findings suggest that an amorphous solid dispersion of ARM could be a viable option for enhancing the dissolution rate of ARM.  相似文献   

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