Preparation of Levofloxacin and Triamcinolone Acetonide Double-loaded Ophthalmic Gel / 中国药房

OBJECTIVE:To prepare Levofloxacin and triamcinolone acetonide double-loaded ophthalmic gel. METHODS:Us-ing levofloxacin hydrochloride and triamcinolone acetonide as main components,carbopol-940P as base material,HPMC K4M as tackifier,Levofloxacin and triamcinolone acetonide double-loaded ophthalmic gel was prepared. Using dissolution time as index, the contents of carbopol-940P and HPMC K4M were determined by single factor test,and dissolution time,viscosity and the con-tents of 2 main components were also determined. RESULTS:The concentrations of carbopol-940P and HPMC K4M were 0.4%and 1.2%,separately. The dissolution time was more than 24 h and viscosity was 1 142.67 Pa·s. The content of levofloxacin hydro-chloride was 97.3% of labelled amount (RSD=0.84%,n=3),and that of triamcinolone acetonide was 92.97% of labelled amount(RSD=1.32%,n=3). CONCLUSIONS:Levofloxacin and triamcinolone acetonide double-loaded ophthalmic gel has been prepared successfully.

Analysis of immobilized L-glutamate oxidase fused with cellulose binding domain on microcrystalline cellulose / 生物工程学报

Immobilization of enzymes is important and widely applied in biocatalysis. Streptomyces platensis gene gox, encoding an extracellular L-glutamate oxidase (Gox), was fused to cellulose binding domain (CBDcex) from Cellulomonas fimi and the recombinant protein Gox-CBD was expressed in Escherichia coli. The fusion protein (Gox-CBD) was immobilized onto microcrystalline cellulose. The preparation conditions, binding capacity, properties and stability of the immobilized enzyme were studied. Under the condition of 4 ℃, for 1 hour, the fusion protein Gox-CBD was able to bind microcrystalline cellulose at a ratio of 9.0 mg of protein per gram of microcrystalline cellulose. Enzymatic properties of free and immobilized L-glutamic oxidase (Gox-CBD) were compared. The specific activity of the immobilized enzyme decreased, but its thermal stability increased a lot compared with that of the free Gox-CBD. After incubation at 60 ℃ for 30 min, 70% of the total activity remained whereas the free recombinant Gox completely lost its activity. The immobilized protein was tightly bound to microcrystalline cellulose at pH below 10 or more than 5 mmol/L NaCl. The fusion protein of Gox-CBD can be specifically immobilized on the microcrystalline cellulose on a single step. Therefore, our findings can provide a novel strategy for protein purification and enzyme immobilization.