Controlled precipitation for enhanced dissolution rate of flurbiprofen: development of rapidly disintegrating tablets

Objective: The aim of this work was to investigate the potential of controlled precipitation of flurbiprofen on solid surface, in the presence or absence of hydrophilic polymers, as a tool for enhanced dissolution rate of the drug. The work was extended to develop rapidly disintegrated tablets.

Significance: This strategy provides simple technique for dissolution enhancement of slowly dissolving drugs with high scaling up potential.

Methods: Aerosil was dispersed in ethanolic solution of flurbiprofen in the presence and absence of hydrophilic polymers. Acidified water was added as antisolvent to produce controlled precipitation. The resultant particles were centrifuged and dried at ambient temperature before monitoring the dissolution pattern. The particles were also subjected to FTIR spectroscopic, X-ray diffraction and thermal analyses.

Results: The FTIR spectroscopy excluded any interaction between flurbiprofen and excipients. The thermal analysis reflected possible change in the crystalline structure and or crystal size of the drug after controlled precipitation in the presence of hydrophilic polymers. This was further confirmed by X-ray diffraction. The modulation in the crystalline structure and size was associated with a significant enhancement in the dissolution rate of flurbiprofen. Optimum formulations were successfully formulated as rapidly disintegrating tablet with subsequent fast dissolution.

Conclusions: Precipitation on a large solid surface area is a promising strategy for enhanced dissolution rate with the presence of hydrophilic polymers during precipitation process improving the efficiency.     

Segmentation of brain MRI using active contour model

Alzheimer disease is a neurodegenerative disorder that impairs memory, cognitive function, and gradually leads to dementia, physical deterioration, loss of independence, and death of the affected individual. In this context, segmentation of medical images is a very important technique in the field of image analysis and Computer‐Assisted Diagnosis. In this article, we introduce a new automatic method of brain images’ segmentation based on the Active Contour (AC) model to extract the Hippocampus and the Corpus Callosum (CC). Our contribution is to combine the geometric method with the statistical method of the AC. We used the Caselle Level Set and added a learning phase to build an average shape and to make the initialization task automatic. For the step of contour evolution, we used the principle of Level set and we added to it the a priori knowledge. Experimental results are very promising. © 2017 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 27, 3–11, 2017     

Multi-level image thresholding using Otsu and chaotic bat algorithm

Multi-level thresholding is a helpful tool for several image segmentation applications. Evaluating the optimal thresholds can be applied using a widely adopted extensive scheme called Otsu’s thresholding. In the current work, bi-level and multi-level threshold procedures are proposed based on their histogram using Otsu’s between-class variance and a novel chaotic bat algorithm (CBA). Maximization of between-class variance function in Otsu technique is used as the objective function to obtain the optimum thresholds for the considered grayscale images. The proposed procedure is applied on a standard test images set of sizes (512 × 512) and (481 × 321). Further, the proposed approach performance is compared with heuristic procedures, such as particle swarm optimization, bacterial foraging optimization, firefly algorithm and bat algorithm. The evaluation assessment between the proposed and existing algorithms is conceded using evaluation metrics, namely root-mean-square error, peak signal to noise ratio, structural similarity index, objective function, and CPU time/iteration number of the optimization-based search. The results established that the proposed CBA provided better outcome for maximum number cases compared to its alternatives. Therefore, it can be applied in complex image processing such as automatic target recognition.

     

Social group optimization for global optimization of multimodal functions and data clustering problems

Neural Computing and Applications - Cost and physical constraints in the engineering applied problems obligate finding the best results that global optimization algorithms cannot realize. For...     

Co-immobilization of chitosan and dermatan sulfate from Raja montagui skin on polyethylene terephthalate surfaces: Characterization and antibiofilm activity

In this work, polyethylene terephthalate (PET) was chemically modified by covalent co-immobilization of two separate layers of bioactive polymers composed of chitosan and a new dermatan sulfate isolated from Raja montagui skin. The new materials obtained were characterized by determination of carboxyl groups, ATR-FTIR spectroscopy, drop water contact angle, SEM, and TGA measurements. The different immobilizations modified the surface characteristics; especially when the first layer was dermatan sulfate (PET–DS–Chito) which presented the best surface wettability (71?±?3°). It also reduced the ability of Staphylococcus epidermidis to form biofilm on PET surfaces which could decrease the virulence of vascular prosthesis infections.     

Synthesis of Novel 2-Thiouracil-5-Sulfonamide Derivatives as Potent Inducers of Cell Cycle Arrest and CDK2A Inhibition Supported by Molecular Docking

In an effort to discover potent anticancer agents, 2-thiouracil-5-sulfonamides derivatives were designed and synthesized. The cytotoxic activity of all synthesized compounds was investigated against four human cancer cell lines viz A-2780 (ovarian), HT-29 (colon), MCF-7 (breast), and HepG2 (liver). Compounds 6b,d–g, and 7b showed promising anticancer activity and significant inhibition of CDK2A. Moreover, they were all safe when tested on WI38 normal cells with high selectivity index for cancer cells. Flow cytometric analysis for the most active compound 6e displayed induction of cell growth arrest at G1/S phase (A-2780 cells), S phase (HT-29 and MCF-7 cells), and G2/M phase (HepG2 cells) and stimulated the apoptotic death of all cancer cells. Moreover, 6e was able to cause cycle arrest indirectly through enhanced expression of cell cycle inhibitors p21 and p27. Finally, molecular docking of compound 6e endorsed its proper binding to CDK2A, which clarifies its potent anticancer activity.     

响应面法优化黄浆水超滤工艺及其代谢组学分析

为了高效分离获得蛋白的同时减轻黄浆水的污染问题,提高其综合利用率,本文采用超滤分离技术对黄浆水进行浓缩处理.在单因素实验基础上,采用响应曲面对黄浆水超滤工艺进行优化,并对超滤前后的黄浆水进行了蛋白质和总糖含量测定、生化需氧量(BOD)和化学需氧量(COD)测定以及代谢组学测定.结果表明:黄浆水超滤浓缩工艺的最佳参数为:...     

A new technique for characterizing floating‐junction‐passivated solar cells from their dark IV curves

The incorporation of a floating junction (FJ) at the surface of a solar cell is a proven means of attaining excellent surface passivation. The development of FJ passivation for commercial use, however, has been hindered by an inherent difficulty in characterizing the FJ itself; to measure FJ parameters directly requires that electrical contact be made to the floating (i.e. uncontacted) layer that forms the FJ, and this is an irreversible process that can alter the properties of the FJ. This paper presents a new, simple technique to characterize an FJ that does not require electrical contact to the floating layer. The Ebers–Moll equivalent circuit is used to derive relationships between the cell parameters of an FJ‐passivated solar cell and the shape of its dark IV curve. With these relationships, lumped, one‐dimensional values can be determined for the current gains and the dark saturation currents of both the contacted and the floating junction, and the shunt resistance across the FJ. The technique is verified with device simulation and then demonstrated on two experimental FJ‐passivated solar cells. Copyright © 1999 John Wiley & Sons, Ltd.