NICORANDIL MUCOADHESIVE MICROSPHERES: FORMULATION DEVELOPMENT, PHYSICO-CHEMICAL AND FUNCTIONAL CHARACTERIZATION

Objective: The study aims to prepare and evaluate Nicorandil mucoadhesive microspheres to improve the oral physicochemical properties of nicorandil and mucoadhesion to extend the residence time at the absorption site. Methods: Nicorandil mucoadhesive microsphere was prepared by emulsion cross-linking method using fenugreek gum, karaya gum as polymer, and glutaraldehyde as a cross-linking agent. Drug entrapment efficiency, particle size, % swelling index, mucoadhesion study, differential scanning calorimetry, powder x-ray diffraction, Fourier transform infrared spectroscopy, and in-vitro dissolution studies were used to characterize the microspheres. Results: The characterization studies indicated the formation of mucoadhesive microspheres. The nicorandil mucoadhesive microspheres particle size is130.83±0.48, entrapment efficiency 66.91±0.54, swelling index 82.69±0.40, % mucoadhesion 95.22±0.13 and in-vitro drug release was found to be 89.96±0.17 % at the end of 12 hrs. Conclusion: This research work successfully formed nicorandil mucoadhesive microspheres formulation using the emulsion cross-linking method. Encapsulation efficiency and other physicochemical and functional characterization of microspheres suggested the successful formation of nicorandil mucoadhesive microspheres

ENHANCED AQUEOUS SOLUBILITY AND IN VITRO DISSOLUTION OF THE ANTI-HYPERLIPIDEMIC AGENT USING SYNTHESIZED SOLID DISPERSION CARRIER

Objective: To improve ATN's solubility, permeability, and dissolution rate, pentaerythritol-eudragit®RS100 co-processed excipients (CE) and their potential as a solid dispersion carrier (ATN-CE-SD). Methods: The ATN-CE-SD was prepared using the solvent evaporation technique. The pure ATN, physical mixture, CE carrier, and optimized ATN-CE-SD was physico-chemically characterized using Scanning electron microscopy, Fourier transforms infrared spectroscopy, differential scanning calorimetry, powder x-ray diffractometry, solubility research, and in-vitro dissolution was used to evaluate solid dispersions. Results: Physical and chemical analysis showed that ATN-CE-SD formed via the involvement of weak intermolecular forces of attraction between CE carrier and ATN. The prepared solid dispersion showed the drug content around ~ 96.94 % w/w, indicating that the solvent evaporation method improved the encapsulation of ATN and, thus, enhanced its drug content. Compared to pure ATN(~ 0.11 mg/mL), ATN-CE-SD (1:2) significantly increased the aqueous solubility by around ~ 25-fold (~ 2.78 mg/mL), indicating solid dispersion improves the solubility of ATN. ATN-CE-SD enhanced the rate of dissolution of ATV (~ 65 %) compared to pure ATN (~ 25 %) and PM (~ 34 %). Likewise, ATN-CE-SD (1:2) improved the rate and extent of ATN (~ 60 %) across the biological membrane compared to pure ATN (~ 22 %) and PM (~ 32 %). The ATN-CE-SD (1:2) improved the dissolution efficiency by around ~ (57.31%) compared to pure ATN (~ 7.02%) and PM (~ 20.43%). According to the study, co-processed excipients could serve as a promising solid dispersion carrier and improve ATN's water solubility, permeability, and dissolution rate. Conclusion: Based on the results, it is possible to use synthetic solid dispersion carriers as alternatives to improve the low water solubility and permeability of ATN

Dept.of Elect & Comm.Engg. B.D.College of Engineering,

An operational amplifier is one of the most commonly used components in analog and digital circuit designs. Low voltage and low power operational amplifier design has become an increasingly interesting subject as many applications switch to portable battery powered operations. The need for design techniques to allow amplifiers to maintain an acceptable level of performance when the supply voltages are decreased is immense. One of the most important features in low voltage amplifier designs is ensuring that the amplifier maintains constant behavior in the presence of rail-to-rail input common mode variations while providing a rail-to-rail output to maximize signal-to-noise ratio. As the supply voltage to a standard CMOS op-amp is reduced, the input common mode range and the output swing get reduced drastically. Special circuits have to be used to raise them up to rail-to-rail supply voltage. In this work we propose a design of a low-voltage CMOS rail-to-rail folded cascode operational amplifier to be realized in a standard 130 nm CMOS technology with 1.2V supply voltage and consumes power less than 400uW. A two stage miller compensated folded cascode op-amp has a UGB>10MHz and achieves a gain>80dB over almost full range of the common mode input voltage

Synergistic Effects of Double Cation Substitution in Solution Processed CZTS Solar Cells with over 10 Efficiency

The performance of many emerging compound semiconductors for thin film solar cells is considerably lower than the Shockley Queisser limit, and one of the main reasons for this is the presence of various deleterious defects. A partial or complete substitution of the cations presents a viable strategy to alter the characteristics of the detrimental defects and defect clusters. Particularly, it is hypothesized that double cation substitution could be a feasible strategy to mitigate the negative effects of different types of defects. In this study, the effects of double cation substitution on pure sulfide Cu2ZnSnS4 CZTS by partially substituting Cu with Ag, and Zn with Cd are explored. A 10.1 total area power conversion efficiency 10.8 activearea efficiency is achieved. The role of Cd, Ag, and Cd Ag substitution is probed using temperature dependent photoluminescence, time resolved photoluminescence, current voltage IV , and external quantum efficiency EQE measurements. It is found that Cd improves the photovoltaic performance by altering the defect characteristics of acceptor states near the valence band, and Ag reduces nonradiative bulk recombination. It is believed that the double cation substitution approach can also be extended to other emerging photovoltaic materials, where defects are the main culprits for low performanc

Suppressed Deep Traps and Bandgap Fluctuations in Cu2CdSnS4 Solar Cells with approx 8 Efficiency

The identification of performance-limiting factors is a crucial step in the development of solar cell technologies. Cu2ZnSn(S,Se)4-based solar cells have shown promising power conversion efficiencies in recent years, but their performance remains inferior compared to other thin-film solar cells. Moreover, the fundamental material characteristics that contribute to this inferior performance are unclear. In this paper, the performance-limiting role of deep-trap-level-inducing 2CuZn+SnZn defect clusters is revealed by comparing the defect formation energies and optoelectronic characteristics of Cu2ZnSnS4 and Cu2CdSnS4. It is shown that these deleterious defect clusters can be suppressed by substituting Zn with Cd in a Cu-poor compositional region. The substitution of Zn with Cd also significantly reduces the bandgap fluctuations, despite the similarity in the formation energy of the CuZn+ZnCu and CuCd+CdCu antisites. Detailed investigation of the Cu2CdSnS4 series with varying Cu/[Cd+Sn] ratios highlights the importance of Cu-poor composition, presumably via the presence of VCu, in improving the optoelectronic properties of the cation-substituted absorber. Finally, a 7.96% efficient Cu2CdSnS4 solar cell is demonstrated, which shows the highest efficiency among fully cation-substituted absorbers based on Cu2ZnSnS4.Ministry of Education (MOE)Accepted versionL.H.W. and S.H. acknowledge the funding support from the CREATE Programme under the Campus for Research Excellence and Technological Enterprise (CREATE), which was supported by the National Research Foundation, Prime Minister’s Office, Singapore; and the Ministry of Education (MOE) Tier 2 Project (MOE2016-T2-1-030). E.A.C. acknowledges support from U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0002120, and from Princeton University for computing resources. V.I.-R. acknowledges support by the H2020 Programme under the project INFINITE-CELL (H2020-MSCA-RISE-2017-777968), by the Spanish Ministry of Science, Innovation and Universities under the IGNITE (ENE2017-87671-C3-1-R), and by the European Regional Development Funds (ERDF, Fons Europeu de Desenvolupament Regional (FEDER) Programa Competitivitat de Catalunya 2007–2013). V.I.-R. belongs to the SEMS (Solar Energy Materials and Systems) Consolidated Research Group of the “Generalitat de Catalunya” (Ref. 2017 SGR 862). T.U. and S.L. acknowledge support by the project INFINITE-CELL (H2020-MSCA-RISE-2017-777968