DESIGN AND EVALUATION OF GUANFACINE EXTENDED RELEASE FORMULATION

Objective: The present study was aimed to develop of the Guanfacine Hydrochloride Extended-release tablets for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). The dosage regimen of Guanfacine Hydrochloride is 4 mg at every 6 h. The concentration of Guanfacine in plasma is fluctuating. Hence, to control the plasma fluctuation and to avoid toxicity problem, Guanfacine Hydrochloride was chosen as a drug with an aim to develop an extended release system for 20 to 24 h. Methods: The design of the system was based on the use of pH-dependent polymer (Hydroxypropyl Methyl Cellulose), pH-independent polymer (Eudragit L 100-55), along with microenvironment modifiers such as organic acid (Fumaric acid) were used in the formulation. Drug-excipient compatibility was studied by FTIR. Before compression, the granules were evaluated for precompression parameters such as bulk density, tapped density, an angle of repose, compressibility index and Hausner’s ratio. After compression, evaluation tests of tablets such as general appearance, hardness, thickness, weight variation, friability, content uniformity, in vitro release studies and stability studies were performed. Results: Out of 9 formulations, the drug release was found to be within the innovator formulation F9. The stability study of formulation F9 revealed there was no significant change in physical and chemical properties of drug stored at 40 °C/75 % RH, 30 °C/65 % RH, 25 °C/60 % RH for 2 mo. Conclusion: Optimized formulation batch F9 showed highest F2 value which indicates similarity with innovator product. The study indicates that Guanfacine Hydrochloride Extended-release tablet was successfully developed

Palladium enriched tungsten oxide thin films: an efficient gas sensor for hazardous gases

Palladium enriched tungsten trioxide thin films were prepared by spraying solution of ammonium tungstate as a precursor on glass substrates using spray pyrolysis deposition technique. Palladium chloride as a precursor for palladium was introduced in the precursor solution during refluxing process before deposition. The catalyst Pd with different concentrations was introduced on series of WO3 films. X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy were applied to analyze structure and morphology of the deposited thin films. The effect of Pd enrichment on the microstructure, electrical and gas sensing properties of the as-synthesized WO3 thin films was studied. Variation in the electrical conductivity of pure and Pd supplemented WO3 films was measured in air and in the presence of hazardous gases such as NO2, SO2 and NH3. The addition of 3 w/o Pd in WO3 raised the gas response of the film to 1.1 towards NO2 at lowest operating temperature of 100 °C. The film shows adequate response towards SO2 (0.32) and NH3 (0.27) at 200 °C and 225 °C, respectively. The response and recovery time ranged in 0.5–1.25 s and 1–6.7 s respectively even for high gas concentrations upto 750 ppm

Ion-beam mixing at the Fe/SiO<SUB>2</SUB> interface: a conversion-electron Mossbauer spectroscopy and x-ray-diffraction study

The effect of ion-beam-induced atomic mixing and subsequent thermal transformations at the Fe:SiO2 (single crystal) interface have been investigated by means of conversion-electron Mossbauer spectroscopy and small-angle x-ray-diffraction measurements. The ion-beam-mixed sample in the as-mixed state shows the presence of the Fe7SiO10 phase along with magnetic Fe-Si-O complexes. The mixed state undergoes structural modifications upon annealing at 450 &#176;C for several hours leading to an increase in Fe3+-to-Fe2+ ratio. The as-deposited sandwich structure upon annealing at 450 &#176;C leads to the formation of metal island structures

Fabrication of polypyrrole gas sensor for detection of NH3 using an oxidizing agent and pyrrole combinations: Studies and characterizations

The organic polymer known as Polypyrrole (Ppy) is synthesized when pyrrole monomers are polymerized. Excellent thermal stability, superior electrical conductivity, and environmental stability are all characteristics of Polypyrrole. Chemical oxidative polymerization was used to synthesize Ppy using Ferric chloride (FeCl3) as an oxidizing agent and surfactant CTAB in aqueous solution. Oxidant (FeCl3) to pyrrole varied in different molar ratios (2, 3, 4 and 5). It was found that increasing this ratio up to 4 increases PPy's conductivity. XRD, FTIR, and SEM were used to characterize Ppy. The conductive nature of Ppy was studied by I–V characteristics. The best conductive polymer is studied for the NH3 gas response

One-Dimensional Layered Sodium Vanadate Nanobelts: A Potential Aspirant for High-Performance Supercapacitor Applications

The one-dimensional (1D) transition metal oxide (TMO) nanostructures have significant advantages in electrochemical energy storage fields. To date, simplifying the processing techniques and improving the yield without compromising the quality are one of the top priorities in pushing these TMO materials for scalable energy storage applications. This study presents a simple ultrasonic-assisted chemical route to prepare Na2V6O16 (NVO) nanobelts. The X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and transmission electron microscopy characterizations are used to confirm the formation of 1D NVO nanobelt structures. The growth mechanism for the formation of NVO nanobelts is also provided. Moreover, these synthesized NVO nanobelts are used as an electrode material for supercapacitor (SC) applications, which exhibit a specific capacitance of 455 F g–1 at 0.5 A g–1 with typical capacitive behavior. An asymmetric coin cell SC device of activated carbon//NVO is also fabricated. This fabricated device delivers a high energy density of 42.4 W h kg–1 and a high power density of 4.3 kW h kg–1, along with 80% capacity retention after 5000 cycles. The 1D NVO nanobelt structures can be considered a promising cathode material with superior rate capability and high capacitance for SC applications