Validation of Microbial Limit Test for Levofloxacin Hydrochloride Gel / 医药导报

Objective To establish a microbial limit test for levofloxacin hydrochloride gel. Methods Ca2+ was added to neutralize the antibacterial activity of quinolone,and to form the insoluble precipitate by binding with carbomer, therefore destroying the stability of macromolecules in the gel. The microbial limit test for levofloxacin hydrochloride gel was confirmed combining with membrane filtration and plate methods. Results The normal plate counting was used in detecting the mold and yeast colony in the gel, the recovery was more than 70%.Simultaneously neutralization centrifugation and membrane filtration were used in bacterial count,with recovery less than 70%,and controlling bacteria test. Conclusion The method is accurate and practical for microbial limit test of levofloxacin hydrochloride gel, but is risky for bacterial counting and needs further risk assessment.

Initial observation of Madin-Darby canine kidney cells being implanted on the polysilicon nanopore membrane by micro-electro-mechanical system / 中华肾脏病杂志

Objective To observe the growing shape and function of Madin-Darby canine kidney (MDCK) cells implanted on the polysilicon nanopore membrane by micro-electro-mechanical system (MEMS). Methods The polysilicon nanomembrane was made by silicon film processed via whirling photoresist, wet etching, electroplating and so on, and then it was coated by extracellular matrix and implanted with MDCK cells. The cell growth shape and function was observed or examined by scanning electron microscope or MTT test and Trypan Blue staining.Results The nanomembrane with regular slit pores was successfully fabricated. Extracellular matrix-coated nanomembrane, especially for collagen Ⅳ coating, was more suitable for MDCK cells to adhere and proliferate without membrane injury. The polysilicon nanomembrane coated with extracellular matrix did not induce the cell death and also not stimulate cells releasing the cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α). Under scanning electron microscope, MDCK cells formed a flat single-cell fusion with tight junction on the surface of polysilicon nanomembrane and there was a large number of microvillus on the top of cells.Conclusion The collagen-coated polysilicon nanomembrane made by MEMS techniques, with no cytotoxicity and good biocompatibility, is valuable to frame the artificial glomerular filtration membrane

Purification of rough cordyceps polysaccharides solution by inorganic ceramic micro-filtration membrane / 中草药

Objective To apply the membrane technology for purifying rough cordyceps polysaccharides solution,the optimal operation condition and effective cleaning method were researched.MethodsTo mainly analyze the flux of membrane and its recovery.Results The optimal experiment operation condition obtained is 60℃,pH value 7-8,and pressure 0.3-0.4 MPa,by which the polysaccharides recovery was about 30%,more than by traditional ethanol extraction,and the most impurities as infusibility substance and protein colloid etc.were taken out.Moreover,the flux of membrane recovery can be above 90% after 80℃ water and 1% NaOH solution was alternately used to wash the fouling membrane under intermittent little back-pulsing. Conclusion The process of membrane technology purifying rough cordyceps polysaccharides is simpl and feasible.