DEVELOPMENT OF MUCOADHESIVE DELIVERY OF CHLORZOXAZONE POLYETHYLENE GLYCOL SOLID DISPERSION

ABSTRACTObjective: Chlorzoxazone (CLZ) is centrally acting skeletal muscle relaxant. It is insoluble in water, so employed for the formation of solid dispersions(SD) as a means to enhance the dissolution rate, and carrier selected was polyethylene glycol 6000 (PEG 6000).Methods: The SDs were prepared by different methods and characterized by in vitro drug release, drug content, fourier transform infraredspectroscopy (FTIR), differential scanning calorimetry, powder X-ray diffraction. All the SD showed dissolution improvement compare to pure drug.These techniques revealed distinct loss of drug crystallinity in the formulation accounting for enhancement in dissolution rate. The SD methodsshowing best in vitro drug release profile were selected in the further development of mucoadhesive buccal patches. A buccal patch has been developedusing two mucoadhesive polymers, i.e. hydroxyl propyl methyl cellulose K4M and carbopol 974. The patches were evaluated for the physicochemical,mechanical and drug release characteristics. The optimized patches showed good mechanical and physicochemical properties to withstand theenvironment of the oral cavity. The in-vitro permeation study showed that patches could deliver drug to the oral mucosa for a period of 8 hrs.Results: The results indicate that suitable bioadhesive buccal patches with good permeability could be prepared. The batches FH4 and FC4 showed81.95% and 79.97% permeated through goat mucosa membrane in 8 hrs. The physicochemical interactions were investigated by FTIR, showed noany evidence of interactions and were present in an unchanged state. The stability study for SD and buccal patch carried out revealed that were stablefor a period of 3-month.Conclusion: Phase-solubility studies indicate significantly increase in solubility. The optimized buccal patches showed good mechanical andphysicochemical properties to withstand environment of the oral cavity.Keywords: Solid dispersions, Chlorzoxazone, Dissolution studies, Buccal patch, In vitro permeation studies

The Offer of Advanced Imaging Techniques Leads to Higher Acceptance Rates for Screening Colonoscopy : a Prospective Study

BACKGROUND: Colonoscopy plays a fundamental role in early diagnosis and management of colorectal cancer and requires public and professional acceptance to ensure the ongoing success of screening programs. The aim of the study was to prospectively assess whether patient acceptance rates to undergo screening colonoscopy could be improved by the offer of advanced imaging techniques. MATERIALS AND METHODS: Overall, 372 randomly selected patients were prospectively included. A standardized questionnaire was developed that inquired of the patients their knowledge regarding advanced imaging techniques. Second, several media campaigns and information events were organized reporting about advanced imaging techniques, followed by repeated evaluation. After one year the evaluation ended. RESULTS: At baseline, 64% of the patients declared that they had no knowledge about new endoscopic methods. After twelve months the overall grade of information increased significantly from 14% at baseline to 34%. The percentage of patients who decided to undergo colonoscopy because of the offer of new imaging methods also increased significantly from 12% at baseline to 42% after 12 months. CONCLUSIONS: Patients were highly interested in the offer of advanced imaging techniques. Knowledge about these techniques could relatively easy be provided using local media campaigns. The offer of advanced imaging techniques leads to higher acceptance rates for screening colonoscopies

Qualitative Robustness of Bootstrap Approximations for Kernel Based Methods

status: publishe

3D-Hydrogen Analysis of Ferromagnetic Microstructures in Proton Irradiated Graphite

Recently, magnetic order in highly oriented pyrolytic graphite (HOPG) induced by proton broad- and microbeam irradiation was discovered. Theoretical models propose that hydrogen could play a major role in the magnetism mechanism. We analysed the hydrogen distribution of pristine as well as irradiated HOPG samples, which were implanted to micrometer-sized spots as well as extended areas with various doses of 2.25 MeV protons at the Leipzig microprobe LIPSION. For this we used the sensitive 3D hydrogen microscopy system at the Munich microprobe SNAKE. The background hydrogen level in pristine HOPG is determined to be less than 0.3 at-ppm. About 4.8e15 H-atoms/cm^2 are observed in the near-surface region (4 um depth resolution). The depth profiles of the implants show hydrogen located within a confined peak at the end of range, in agreement with SRIM Monte Carlo simulations, and no evidence of diffusion broadening along the c-axis. At sample with microspots, up to 40 at-% of the implanted hydrogen is not detected, providing support for lateral hydrogen diffusion.Comment: accepted for publication in Nucl. Instr. and Met

CST: Constructive Solid Trimming for Rendering BReps and CSG

To eliminate the need to evaluate the intersection curves in explicit representations of surface cutouts or of trimmed faces in BReps of CSG solids, we advocate using Constructive Solid Trimming (CST). A CST face is the intersection of a surface with a Blist representation of a trimming CSG volume. We propose a new, GPU-based, CSG rendering algorithm, which trims the boundary of each primitive using a Blist of its Active Zone. This approach is faster than the previously reported Blister approach, eliminates occasional speckles of wrongly colored pixels, and provides additional capabilities: painting on surfaces, rendering semitransparent CSG models, and highlighting selected features in the BReps of CSG models