A simple and high efficient composite based on g-C3N4 for super rapid removal multiple organic dyes in water under sunlight

A simple and high efficient porous composites via the solvent evaporation method using g-C3N4 and NiSO4 was developed. It can super rapidly remove multiple organic dyes in water including rhodamine...

Evaluation of the Influence of Stirring Speed on the Release Kinetics of Fexofenadine HCl Polymeric Microspheres

Microspheres, a potential drug delivery approach, has opened a new era for attaining versatile release patterns needed. By optimizing the formulation variables, they can be prepared to obtain targeted release, immediate release, sustained release patterns. The release of the active drug material depends upon a number of formulation parameters such as polymers, stirring speed (rpm), methodology, surfactants, etc. Fexofenadine hydrochloride (HCl) is a second generation antihistamine. Our present research has explored the effects of using different rpm (600- 1000 rpm) in preparing fexofenadine hydrochloride (HCl) microspheres by emulsion solvent evaporation method. The formulation is aimed to provide sustained release for the required long period with a high margin of safety. We used a blended mixture of Hydroxy Propyl Methyl Cellulose (HPMC) K 100 MCR and Eudragit RL100 polymers to have sustained-release microspheres. The impact of different rpm on Yield, drug encapsulation efficiency, flow properties, and dissolution pattern were appraised. We observed the release of the drug for 10 hours in phosphate buffer (pH 6.8) and evaluated the drug release spectrophotometrically. Our study finds that the release of fexofenadine HCl from the microspheres was significantly increased with drug loading. We found the dosage forms to follow Higuchi release kinetics and Hixson-Crowell release kinetics the most, indicating successful achievement of sustained-release pattern in the dosage form. The change in drug release rate was statistically significant for variation in the stirring rate. We found that 600 rpm was the most optimized stirring rate for preparing microspheres in the emulsion solvent evaporation method.

Facile and Scalable Synthesis and Self-Assembly of Chitosan Tartaric Sodium

Chitosan-based nanostructures have been widely applied in biomineralization and biosensors owing to its polycationic properties. The creation of chitosan nanostructures with controllable morphology is highly desirable, but has met with limited success yet. Here, we report that nanostructured chitosan tartaric sodium (CS-TA-Na) is simply synthesized in large amounts from chitosan tartaric ester (CS-TA) hydrolyzed by NaOH solution, while the CS-TA is obtained by dehydration-caused crystallization. The structures and self-assembly properties of CS-TA-Na are carefully characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), X-ray diffraction (XRD), differential scanning calorimeter (DSC), transmission electron microscopy (TEM), a scanning electron microscope (SEM) and a polarizing optical microscope (POM). As a result, the acquired nanostructured CS-TA-Na, which is dispersed in an aqueous solution 20–50 nm in length and 10–15 nm in width, shows both the features of carboxyl and amino functional groups. Moreover, morphology regulation of the CS-TA-Na nanostructures can be easily achieved by adjusting the solvent evaporation temperature. When the evaporation temperature is increased from 4 °C to 60 °C, CS-TA-Na nanorods and nanosheets are obtained on the substrates, respectively. As far as we know, this is the first report on using a simple solvent evaporation method to prepare CS-TA-Na nanocrystals with controllable morphologies.

Formulation Development and Evaluation of Sustained Release Microsphere of Levetiracetam

The aim of the present work was to develop and evaluate of oral microsphere of Levetiracetam to reduce the frequency of dosing by achieving 12 hours sustained drug release. The microsphere formed will also mask the bitter taste of the drug and thus increase the compatibility of the drug with the patients. Levetiracetam is a second-generation anti-epileptic agent useful in the treatment of partial onset and monoclinic seizures. It has a short half life of 7 hours and its recommended dose is 500 mg twice a daily. Microspheres are suitable drug delivery system for such drug candidate. For these reasons it is must to formulate a suitable dosage form by which it will be easier to administer the dose and also to get a sustained drug release hence microsphere was prepared using solvent evaporation method. Preformulation studies were carried out to rule out any drug polymer interaction by FTIR technique. In this study formulation was done solvent evaporation method using different percentage of HPMC– K 100, HPMC- K 15 and coated with Eudragit S100. Drug, polymer and physical mixture were evaluated for in compatibility study by Fourier transforms infrared spectroscopy. All the batches of microsphere (F1 to F5) were subjected for in vitro dissolution. Microsphere was evaluated for surface morphology, micromeritics properties, entrapment efficiency and in vitro drug release. The entrapment efficiency of microsphere ranged from 71.16%-73.66%. The size of the prepared microsphere ranges between 42.8 µm to 55.64 µm which was found to increase with increase in RPM at same polymer ratio. Micromeritics studies showed good flow properties. Among the microsphere batches, F5 was observed as an optimized batch as its formulation with polymer i.e. Eudragit-S 100 and HPMC-K 100 was found to be release in sustained manner. The F-5 batch shows is 79.45% drug release at the end of 7 hrs and its stability study indicate that these microspheres were stable at selected temperature and humidity