Preparation, characterization and biodegradability performance of poly(3-hydroxybutyric acid)/polyvinyl acetate films / Olla H. S. Sharhan

In this work, microbial polyester, poly(3-hydroxybutyric acid) (PHB) was blended with polyvinyl acetate (PVAc) in various composition %(100/0, 95/5, 90/10, 85/15, 80/20, 75/25, 70/30, 65/35 and 0/100) and the film for each ratio was prepared by the solution casting method. The prepared films were then characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) for information regarding chemical structure and surface morphology of the films. Thermal stability of the blends was investigated by thermogravimetric analysis (TGA) while the melting point and glass transition temperatures (Tg) were investigated by Differential Scanning Calorimetry (DSC) at a heating rate of 10 oC min-1. Results showed that the thermal stability increased with increasing PVAc ratio. In addition the blends were also characterized by X-Ray Diffraction (XRD). For the biodegradability studies the films were buried in the soil for various specified days followed by chemical analysis. Intermolecular hydrogen bonding was observed from FTIR spectra and the best improvement in thermal stability and mechanical properties was shown by the blend ratio of PHB/PVAc (65/35). Biodegradability of the blends was studied by volume change measurement at room temperature and it was found to improve with increasing PVAc content. Blends of poly(hydroxyalkanoate) (PHA) with other biodegradable polymers also usually show similar improved biodegradability when compared with pure poly (hydroxyalkanoates) (PHAs)

Preparation and characterization of poly(3-hydroxybutyric acid)/poly(vinyl acetate) blend films

Modification of poly(3-hydroxybutyric acid) (PHB) films by blending with poly(vinyl acetate) (PVAc) was investigated. The variation effect of poly(vinyl acetate) proportions in PHB/PVAc blend on the chemical structure, thermal stability, melting and phase morphology and crystallization behaviour were studied. The structure was characterized by Fourier transform infrared, thermogravimetric analysis, X-ray Diffraction (XRD) and field emission scanning electron microscopy. The properties of poly(3-hydroxybutyric acid) were found to be improved by blending with poly(vinyl acetate) and the level of improvement is a function of the proportion of poly(vinyl acetate) in the blend. The thermal stability for the blending was more stable than the pure polymers. The TGA results of the prepared polymers showed three-step decomposition assigned to the thermal degradation of poly(3-hydroxybutyric acid) hard and poly(vinyl acetate). For the XRD, the crystallization rate was decreased by blending poly(3-hydroxybutyric acid) with poly(vinyl acetate)

Formulation of New Chewable Oral Dosage Forms of Meclizine and Pyridoxine Hydrochloride

Nausea and vomiting are symptoms associated with a lot of diseases and oral tablets may be unprofitable for patients especially those suffering from nausea and vomiting. Therefore, this study aimed to formulate a new meclizine and pyridoxine combination formula for chewable tablets and provide rapid drug absorption and decrease motion sickness. The new chewable formulation has been prepared to provide fast action, is more acceptable, and could be used for all age categories. Seven trials haves been carried out to prepare to find the suitable one where formula 7 of the chewable gum preparation exhibited good taste and hardness, while the gelatin formulation give an accepted formula after four trials with better taste and good acceptance. The prepared formulations give a dissolution profile of meclizine (95.53–102.8%) and pyridoxine (99.25 ± 115%) and assay (98 + 0.05–99.3 ± 0.8%) for meclizine and (97 ± 0.9–100.0 ± 0.08%) for the pyridoxine in three prepared formulations of chewable tablets. Followed by the evaluation, the formulation and testing them on human volunteers are carried out to confirm their effect to ensure acceptance and fast actions. The finding is promising for preparing a new route of administration of meclizine and pyridoxine combination to be used in the market

Synthesis and biological study of acridine-based imidazolium salts

A new series of acridine based imidazolium salts was synthesized and evaluated for in vitro cytotoxicity against human cancer cell lines by an MTT assay. The synthesis applied a coupling of imidazoles with 9-chloroacridines, which originated from an Ullmann condensation of a 2-chloro-benzoic acid with an aniline. The target compounds were obtained in high yields. The DPPH assay indicated considerable antioxidant activity for target compounds with simple and short alkyl chains on the imidazole, while increasing chain length and the introduction of an additional π-electron system in most cases reduced the activity. All compounds exhibited low biotoxicity against non-cancerous cell lines, whereas a few compounds showed promising anticancer activity. Unlike for the reference drugs Tamoxifen and Paclitaxel, the anticancer activity of acridine imidazolium ions is specific for only selected cancer types. Reasonable fluorescent behaviour of the products provide potential for visualization of the distribution of active drugs in tissue