OBJECTIVE:To optimize the preparation technology of roxithromycin microspheres.METHODS:The microspheres of roxithromycin were prepared by the emulsion-solvent diffusion method with ethylcellulose used as capsule wall material.The preparation technology of microspheres was optimized by orthogonal experiment taking encapsulation efficiency as index with the ratio of roxithromycin to ethylcellulose(A),the concentration of ethylcellulose(B)and the ratio of water phase to oil phase(C)as factors.The appearance,particle diameter,drug-loading amount,encapsulation efficiency,in vitro release and bitter smell were studied.RESULTS:The optimal preparation conditions were as follows:A was 1∶1,B was 30 ?g?mL-1 and C was 4∶1.The microspheres obtained were round and well-distributed with mean diameter of 75.0～90.0 ?m,drug-loading amount of 45%～46%,encapsulation efficiency of over 90% and sustained release for over 13 hours.No bitter taste of the roxithromycin-ethylcellulose microspheres was felt by the majority of subjects.CONCLUSION:The roxithromycin microspheres made by optimization technology was bitter-masked and sustained release.

OBJECTIVE:To optimize the formulation of dextromethorphan hydrobromide sustained-release tablets. METHODS: The dextromethorphan hydrobromide sustained-release tablets were prepared with HPMC as sustained release matrix. Orthogonal test was performed to optimize the formulation with in vitro accumulative drug release rate as index and the amount of HPMC and lactose as well as ethylcellulose (EC) concentration as factors. Then verification test on the in vitro drug release characteristics of the optimized tablets were performed and the influencing factors (high temperature,high light,and high moisture) were investigated as well. RESULTS: The optimized formulation of dextromethorphan hydrobromide sustained-release tablets was as follows: 30 mg HPMC,50 mg lactose,and 8% EC. The accumulative drug release rate at 8 h was above 70%. In the influencing factor test,the tablets were stable under all conditions except at high moisture condition. CONCLUSION: The optimized formulation of dextromethorphan hydrobromide sustained-release tablets is feasible.

Objective To investigate the current situation of healthcare-associated infection(HAI)management in secondary and above medical institutions in Shaanxi Province,analyze development trend,and put forward sugges-tions for improvement.Methods In May-June,2016,170 secondary and above hospitals in 10 cities were selected for surveying through stratified random sampling method.Survey content included basic situation of hospitals,HAI management,HAI monitoring,and so on.Results Available questionnaires were obtained from 165 hospitals (43 tertiary hospitals,and 122 secondary hospitals).Of 165 hospitals,more than 90% have established HAI manage-ment organizations and regulations,but hospital risk management should be paid more attention,only 63.03% of hospitals perfected the risk management system and 66.06% conducted risk assessment.99.09% of hospitals im-plement training on HAI to all staff regularly and 88.41% conducted effective feedback.In the aspect of staff alloca-tion,88.48% of the hospitals assigned enough professionals for HAI management,but only 34.55% have specific training programme for these personnel.Only 33.94% of hospitals have special funds for HAI control;in the aspect of monitoring on HAI,21.21% of hospital installed and used HAI monitoring software;In the aspect of implemen-tation of monitoring programme,about 90% of hospitals developed monitoring on HAI cases and environmental hy-giene,but only 34.55% and 23.64% of hospitals conducted targeted monitoring on intensive care unit and neonatal intensive care unit respectively.Conclusion Organizational structure of HAI management in Shaanxi Province is perfect,relevant rules and regulations are basically established,basic monitoring projects are universal,but the awareness of risk management needs to be strengthened,professional allocation and professional quality develop-ment are both imbalance,informational monitoring is inadequate.

Objective To study the effect of ultrasound-mediated microbubble on the concentration of cefuroxime in rat prostate. Methods Twenty male SD rats were randomly divided into the experimental group ( ultrasound-mediated microbubble+cefuroxime group) and the control group ( cefuroxime group) . The experimental group was given cefuroxime and microbubble via the tail vein, and then the prostates were exposed to ultrasonic irradiation for five minutes. The control group was given cefuroxime and the same amount of normal salin via the tail vein, and then given sham ultrasonic irradiation for five minutes. After the prostate was taken, cefuroxime concentration in pros-tate was measured by high performance liquid chromatograph. Results Concentration of cefuroxime in the experimental and the control group were (16. 274 ± 9. 515) μg/mg and (8. 336 ± 6. 743) μg/mg respectively. Compared to the control group, the concentration of cefuroxime was significant higher in the experimental group, and the difference is statistically significant (P <0. 05). Conclusion Low-dose ultra-sound-mediated microbubble can significantly improve the permeability of rat prostate tissue, thereby enhancing the drug concentration in prostate tissue.

Based on microfabrication technology and electrochemical modification method, a micro electrochemical sensor for nitrate ( NO-3 ) determination was developed. A micro sensor chip with working electrode and counter electrode was used as the signal convertor of the sensor. The area of the micro working_electrode was only 1 mm2 . As an electrocatalysis sensitive material, copper was electrodeposited onto the working electrode by square_wave pulse current electrodeposition method. The morphologies and components of freshly deposited materials were examined by scanning electron microscopy ( SEM ) and X_ray diffraction ( XRD) to explore key factors that affected the electrocatalytic ability of the deposited copper layer for reducing nitrate ions. The experimental results revealed that under the optimal conditions, the deposited copper layer was macroporous and had a larger effective surface area that could serve as a more effective electrocatalyst in facilitating nitrate reduction. Electrochemical response of the macroporous copper layer was characterized by linear sweep voltammetry in acidic supporting electrolytes ( pH=2 ) . The electroanalytical results showed that the modified microsensor had marked sensitivity for standard nitrate samples within the concentration range from 12. 5 to 3000 μmol/L (in the range of 12. 5-200 μmol/L yielded straight line:y1=-0. 1422x-10. 326, R12=0. 9976, while in the range of 200-3000 μmol/L yielded straight line: y2=-0. 0984x-22. 144, R22=0. 9927) with a detection limit of 2 μmol/L (S/N=3). The developed electrochemical microsensor was also employed for nitrate determination in water samples collected from lakes and rivers near the city of Beijing. The results were in good agreement with the data given by qualified water quality detection institute, with the deviations from 3 . 9% to 15 . 4%.