Effects of Coating Method on Fabrication Quality of Flexible Silicone Blood Vessels / 医用生物力学

Objective To investigate the effect of different coating methods on production quality of complex and flexible silicone vascular replicas. Methods Based on models of anterior communicating artery aneurysms, several patient-specific models were made by using spray-coating method and brush-spin-coating method respectively, and two methods for making the same vascular structure were quantitatively compared in terms of thickness growth, circumferential uniformity and light transmittance. Results Brush-spin-coating method was better than spray-coating method in the thickness control and coating uniformity for fabrication of vessels with large curvature, variable diameter and straight tube, and the model had preferably light transmittance and surface smoothness. The relative deviation of thickness by brush-spin-coating method was decreased by 8. 9% , 10. 8% and 16. 9% respectively compared with spray-coating method. Conclusions At present stage, the brush-spin coating method has the advantage of thickness uniformity and light transmittance over the spray-coating method in making silicone phantoms, and it has promising application prospects in fluid mechanics field of in vitro experiment on large vessels.

Progress in Research Drug Eluting Stents Drug-looding and Drug Release Kinetics / 中国医疗器械杂志

Drug eluting stents are one of the main devices of coronary intervention, which play a therapeutic role through the combination of medical devices. Drug is an important part of the drug eluting stents. The loading method, the type of carrier, drug and carrier interaction and the preparation process of the drug directly affect the drugs release kinetics characteristics of the device and the final treatment. According to the characteristics of the drug coating, drug coated stents can be divided into non-degradable polymers drug coated stents, biodegradable polymers drug coated stents and polymer-free drug eluting stents. This article discussed the stent coating process and drug release kinetics of the three types of drug eluting stent.

Preparation of palmatine-loaded flexible nano-liposomes films based on Bletilla striata polysaccharides / 中草药

Objective To prepare palmatine-loaded flexible nano-liposomes (PFL) films with Bletilla striata polysaccharide (BSP) as membrane material, and evaluate its pharmacy related performance in order to lay the foundation for further application. Methods The PFL was prepared by injection method and the films of PFL based on Bletilla striata polysaccharide (PFL-BPF) was prepared by homogenate coating method. The PFL-BPF was characterized and evaluated by electron microscopy, differential scanning calorimeter (DSC), and in vitro transmucosal membrane experiment. Results The PFL and BSP had good compatibility and easy to film with BSP as membrane material. The appearance of PFL-BPF obtained was smooth, non-bubble, flexible, and suitable stiffness; PFL-BPF had good biological adhesion. The time of scouring the film agent from mucous membrane with normal saline was (130 ± 7) min. At 0.5 h, the dose of PFL-BPF promoting palmatine (PA) infiltration to mucosa was 32.41 μg/g. It was 3.17 times higher than those of PA solution based on BSP (PL-BPF) and 1.9 times for PA common liposomes based on BSP (BLP + PA-BPF) (t-test, P < 0.05); At 2.5 h, it was 2.67 times and 1.89 times higher than those of PL-BPF and BLP + PA-BPF, respectively. It showed that PFL-BPF could significantly promote the water-soluble drug PA through mucosa membrane and release it slowly. The results of DSC showed that the possible mechanism for promoting the absorption of PA through mucosa membrane was that the flexible liposomes disturbed the mucosal epithelial cells and carried the drug into the mucosal tissue. Conclusion The PFL-BPF had the advantages of good film-forming property, lasting adhesive attraction, strong scour resistance, simple and feasible preparation process, and could promote drug permeation into mucosa obviously. Therefore, the flexible nano-liposomes film is a good drug carrier for the transmucosal drug delivery applications and has a wide application prospect.

Preparation of colon-targeted pellets of Prunellae Spica effective components and the in vitro drug-release behaviors / 中成药

AIM To prepare colon-targeted pellets of Prunellae Spica effective components and to evaluate the in vitro drug-release behaviors.METHODS Fluidized bed coating method was adopted in the preparation of pellets.With in vitro accumulative release rate as an evaluation index,hydroxypropyl methyl cellulose (HMPC),polyacrylic resin (Eudragit S100) and triethyl citrate (TEC) amounts as influencing factors,orthogonal test was applied to optimizing the formulation.The in vitro drug-release behaviors were evaluated with rosmarinic acid content as an index.RESULTS The optimal formulation was determined to be 5％ for HPMC amount,70％ for Eudragit S100 amount,and 20％ for TEC amount.The obtained pellets attained an accumulative release rate of more than 90％ in pH 7.6 PBS (transportation for 2 h),while no drug dissolution was found in pH 1.0 HCl (transportation for 2 h) or pH 6.8 PBS (transportation for 3 h).CONCLUSION Colon-targeted pellets of Prunellae Spica effective components can achieve in vitro colon-targeted effect.

Preparation and in vitro evaluation of diclofenac potassium delayed-sustained release pellets / 中国药科大学学报

Diclofenac potassium delayed-sustained release pellets were prepared by double-layer coating method with ethylcellulose aqueous dispersion.The effects of release condition and pellet compositions on the in vitro drug release were evaluated.The formulation was optimized by the central composite design-response surface methodology.It was shown that the pH of the media greatly affected the in vitro drug release of the pellets while the viscosity of the media had little influence.Drug release from the pellets was related to the proportion of the inner coat to the outer coat and the amount of pore forming agent in the outer coat.The optimization of the formulation could be achieved by the central composite design-response surface methodology.

Advantages of PROSTALAC Prepared by Modified Cement-coating Method / 대한정형외과학회잡지

PURPOSE: To report the clinical advantage and effect of our modified cement-coating method of PROSTALAC for the treatment of infected hip arthroplasty. MATERIALS AND METHODS: Twenty seven patients (mean age, 57), who had been treated with PROSTALAC after an infected hip arthroplasty, were enrolled in this study. Before surgery, the femoral stem was sterilized with gamma-radiation. During the operation, the stem was coated with antibiotics-impregnated cement and introduced into the femoral canal by several repeats of an insertion and removal procedure, just like a piston movement, to fit the stem into the intramedullary canal space. A bipolar hemiarthroplastic polyethylene liner was used for acetabular cup cement-fixation. A periodic hematologic test, such as ESR and CRP, the ability of early ambulation, leg length discrepancy and hip flexion, were checked for the clinical evaluation. RESULTS: CRP was normalized by an average of 4.2 weeks after the PROSTALAC operation. Partial weight bearing was possible 2 weeks after surgery, and mean leg length discrepancy and flexion of hip was 1.4 cm and 63.5degrees, respectively. PROSTALAC was still retained in 5 cases with satisfactory function. Reinfection after final reimplantation (22 cases) was noted in 4 cases (18.2%). Neither dislocation nor periprosthetic fracture occurred after reimplantation. CONCLUSION: The 2 phase treatment with PROSTALAC is an effective method for infected hip arthroplasty. PROSTALAC has considerable benefit for providing daily acting ability before the final reimplantation provided the appropriate surgical technique and strict sterilization of the inserted implements are combined.

A comparative study of physical properties of TiO2 thin films according to a coating method on orthodontic wires and brackets / 대한치과교정학회지

The purpose of this study was to search for an appropriate method of coating TiO2 on orthodontic appliances. TiO2 thin films were deposited on orthodontic wires and brackets using sol-gel, CVD (Chemical Vapor Deposition) and PE-CVD (Plasma Enhanced-CVD) methods. The roughness of TiO2-coated surfaces was investigated via scanning electron microscope (SEM) and adhesive strength of TiO2 thin films was measured by adhesive tape pull test. Methylene blue degradation test was carried out to evaluate the photocatalytic activity of TiO2 and the corrosion resistance of TiO2 thin films against fluoride solution was also analyzed by observing the surfaces of TiO2-coated wires and brackets via SEM after immersion in sodium fluoride solution. Through the comparison of properties and photocatalytic activity of TiO2 thin films according to the coating methods, the following results were obtained. Smoother surfaces of TiO2 thin films were generated by CVD or PE-CVD methods than through the sol-gel method or the control. Adhesive strength of the TiO2 thin films was highest in PE-CVD and gradually became lower in the order of CVD, then the sol-gel method. Photocatalytic activity of TiO2 thin films on methylene blue was the highest in PE-CVD and gradually became lower in the order of CVD, then the sol-gel method. Corrosion resistance of TiO2 thin films against fluoride solution was stronger in CVD and PE-CVD methods than in the sol-gel method. The results of this study suggest that the CVD or PE-CVD methods is more appropriate than the sol-gel method for TiO2 coating on orthodontic wires and brackets.

Preparation of a Three-pulse Drug Release System of Nimodipine / 中国药房

OBJECTIVE:To prepare a three-pulse drug release system of nimodipine and study its drug release.METHODS:Solid dispersion technique and dry-coating method were respectively applied to prepare immediate-release mini-tablets and Pulsatile mini-tablets with lag-time of 4 h or 8 h.Then those mini-tablets were filled into capsule to obtain a three-pulse drug release system and subjected to in vitro dissolution test.DSC was employed to determine drug status in solid dispersion.RESULTS:Immediate-release mini-tablets were released more than 95% in 30 min.Pulsatile mini-tablets were released less than 10% in 4 h or 8 h of lag-time period.After lag-time period,pulsatile mini-tablets were released completely in 3 h.The whole pulsatile drug release system achieved three times of drug release at 5 min,4 h,8 h,respectively.Nimodipine kept amorphous form and were delivered into carrier evenly.CONCLUSION:A three-pulse drug release system of nimodipine has been prepared successfully.