Avicel is made of a mixture of microcrystalline cellulose (MCC) and carboxymethyl cellulose (CMC), and used for virus plaque assay. The avicel in common use is produced by FMC Biopolymer. Due to the relatively fixed proportion of MCC and CMC, avicel in common use is not suitable for plaque determination experiment of all types of viruses. In this study, we evaluated the effect of avicel made of different proportions of MCC and CMC on virus plaque assay, and developed an improved avicel virus plaque assay featured with simple and convenient operation, good practicability and high stability. To generate avicel overlays with different proportions of MCC and CMC, twelve different 2×avicel solutions were prepared. Their overall viscosity and bottom viscosity were measured to evaluate the ease of operation. The results showed that most of the 2×avicel solutions (except the 4.8% MCC+1.4% CMC and 4.8% MCC+1.0% CMC group) were easy to absorb and prepare nutrient overlap than 2×CMC solution. In order to find the best scheme to detect the titer of porcine epidemic diarrhea virus (PEDV), these avicel overlay solutions with different proportion of MCC and CMC were used as a replacement in the standard plaque assay. By comparing the size, clarity, stability and titer accuracy of virus plaque, we identified that 0.6% MCC and 0.7% CMC was the most preferable composition of avicel overlay for PEDV plaque assay. In conclusion, we developed an improved virus plaque assay based on avicel, which may facilitate the research of virus etiology, antiviral drugs and vaccines.
Animals ; Carboxymethylcellulose Sodium/chemistry* ; Cellulose/chemistry* ; Swine

The present study prepared a new type of Ginkgo biloba ketone ester(GBE50) preparation from polyethylene glycol and croscarmellose sodium with good biocompatibility and a certain viscosity by fused deposition modeling(FDM)-type 3D printing technique. Firstly, a cylindrical 3D printing model with a diameter of 9.00 mm and a height of 4.50 mm was established. Subsequently, the 3D-GBE50 preparations with three paths(concentric, zigzag, and grid), different layer heights, and different filling gaps were designed and prepared after the optimization of the proportions of excipients. The morphology, size, chemical properties, and dissolution activity of the 3D-GBE50 preparations were fully characterized and investigated. The results showed that 3D-GBE50 preparations had smooth appearance, clear texture, standard friability, good thermal stability, and stable chemical properties. Moreover, the printing path, layer height, and filling gap were directly related to the release rate of 3D-GBE50 preparations. The dissolution of 3D-GBE50 tablets with zigzag printing path was the fastest, while the dissolution rates of 3D-GBE50 tablets with concentric circle and grid-shaped printing paths were slower than that of commercially available G. biloba Ketone Ester Tablets. In addition, the dissolution of 3D-GBE50 tablets was faster with higher layer height and wider filling gap. As revealed by the results, th FDM-type 3D printing technique can flexibly regulate the drug release activity via controlling the printing parameters, providing effective ideas and methods for the pre-paration of personalized pharmaceutical preparations.
Carboxymethylcellulose Sodium ; Esters ; Excipients/chemistry* ; Ginkgo biloba ; Ketones ; Polyethylene Glycols/chemistry* ; Printing, Three-Dimensional ; Tablets/chemistry* ; Technology, Pharmaceutical/methods*

Albendazole is an orally administered broad-spectrum benzimidazole anthelmintic used against helminthiasis, hydatid cyst disease and neurocysticercosis. The objectives of this investigation are to develop a sustained release drug delivery system for albendazole, and to target its delivery to colon. Albendazole matrix tablets containing varying proportions of single and binary blends of four polymers; polyacrylic acid (carbopol 971), ethylcellulose (Etcell), eudragit L100-55 (EUD), and sodium carboxymethyl cellulose (CMC) were prepared by a modified wet granulation technique of kneading, extrusion and compaction. In vitro release profiles of albendazole was sequentially determined in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) without enzymes and in rat caecal content medium (RCCM) at 37 degrees C. The in vitro drug release from matrix tablets containing CMC and Etcell as single polymers showed initial burst effect in the first 2 h (>20% and 50% respectively), followed by a slow release in SIF. However, matrix tablets containing polymer blends showed that no appreciable drug release occurred up to 5 h. Drug release from tablets containing polymer blends in the dissolution medium containing rat caecal material suddenly increased to > or =30% after 5 h (RCCM), and reaching up to 90% in 24 h. Albendazole matrix tablets containing carbopol 971, Etcell, EUD, and CMC as single polymers and as blends were formulated for oral use. Drug release from the tablet matrices containing carbopol alone, binary blends of carbopol/Etcell, and CMC/EUD were found to be very slow and dependent on polymer concentration. Matrix tablets containing blends of these polymers formulated using kneading, extrusion and compaction technique could provide sustained drug release and can be utilized in the colonic delivery of albendazole.
Acrylic Resins ; chemistry ; Administration, Oral ; Albendazole ; administration & dosage ; pharmacokinetics ; Animals ; Anthelmintics ; administration & dosage ; pharmacokinetics ; Carboxymethylcellulose Sodium ; chemistry ; Cellulose ; analogs & derivatives ; chemistry ; Colon ; metabolism ; Delayed-Action Preparations ; Drug Carriers ; chemistry ; Drug Compounding ; Drug Delivery Systems ; In Vitro Techniques ; Male ; Rats ; Tablets ; Technology, Pharmaceutical ; methods

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) may cause infections during wound dressing. We aimed to compare the antibacterial activities and wound-healing effects of commercially available silver-coated or silver-impregnated wound dressings on MRSA-infected wounds. METHODS: Full-thickness skin defects were made on the back of rats (N=108) and were infected with MRSA. The rats were divided into the following 6 groups according to the dressing used for the wounds: nanocrystalline silver (Acticoat(R)), silver carboxymethylcellulose (Aquacel(R)-Ag), silver sulfadiazine (Medifoam silver(R)), nanocrystalline silver (PolyMem silver(R)), silver sulfadiazine (Ilvadon(R)), and 10% povidone iodide (Betadine(R)). We analyzed the wound sizes, histological findings, and bacterial colony counts for the groups. We also inoculated the silver materials on Mueller-Hinton agar plates containing MRSA and compared the inhibition zones in the agar plates. RESULTS: The order of the rate of wound-size decrease was Acticoat(R)>Aquacel(R)-Ag>PolyMem silver(R)>Medifoam silver(R)>Ilvadon(R)>Betadine(R). The histological findings revealed that the Acticoat(R) showed more reepithelialization and granulation tissue formation and less inflammatory cell infiltration than the other materials. The order of the time required for wound healing was Acticoat(R)>Aquacel (R)-Ag>PolyMem silver(R)>Ilvadon(R)>Medifoam silver(R)>Betadine(R). The bacterial colony counts reduced in all the groups, except in the Medifoam silver(R) group. The order of the size of the inhibition zone was Acticoat(R)>Aquacel(R)-Ag>Ilvadon(R)>PolyMem silver(R)>Betadine(R)>Medifoam silver(R). CONCLUSIONS: Silver-coated or silver-impregnated wound dressings can be used for treating MRSAinfected wounds. Considering its superior efficacy in comparison to the efficacies of other silver-coated or silver-impregnated wound dressings, Acticoat(R) should be preferentially used for the treatment of MRSA-infected skin wounds.
Animals ; Bandages ; Carboxymethylcellulose Sodium/therapeutic use ; Female ; Metal Nanoparticles/therapeutic use ; *Methicillin-Resistant Staphylococcus aureus ; Povidone-Iodine/therapeutic use ; Rats ; Rats, Sprague-Dawley ; Silver/chemistry/*therapeutic use ; Silver Sulfadiazine/therapeutic use ; Skin/pathology ; Staphylococcal Infections/*drug therapy/pathology ; Wound Healing/*drug effects