scholarly journals FORMULATION AND EVALUATION OF NANOSUSPENSION OF VALSARTAN

2018 ◽  
Vol 10 (2) ◽  
pp. 68
Author(s):  
Manishaanjane . ◽  
Shikha Agrawal ◽  
Amreen Khan
Keyword(s):  
Uv Spectroscopy ◽  
Research Work ◽  
Methyl Cellulose ◽  
Water Soluble ◽  
Buffer Solution ◽  
Drug Sample ◽  
Ph Buffer Solution ◽  
Ph Buffer ◽  
Novel Drug

Objective: The objective of the present research work was to formulate and evaluate Valsartan nanosuspension by nanoprecipitation ultra sonication method using different polymers to enhance solubility and bioavailability of the poorly water-soluble drug.Methods: Formulation of nanosuspension of valsartan by nanoprecipitation technique was used. The nanosuspension formulations were prepared using different polymers such as hydroxyl propyl methyl cellulose E50, polyvinyl pyrollidone k-30, polyethene glycol 6000 and sodium lauryl sulphate was used as the surfactant.Results: The formulation of nanosuspension was formed clear and no sedimentation was seen on further shaking. The nanosuspension formulations were Valsatan shows maximum solubility in HPMC as a non-volatile solvent. All the Preformulation parameters were evaluated such as organoleptic characterization of drug sample, melting point, pH, partition coefficient, identification of drug samples by using UV spectroscopy and FTIR analytical method, preparation of calibration curves, solubility studies of drug sample like qualitative, quantitative and pH dependent solubility of drug in different pH buffer solution. The viscosity of the dispersion medium was more in F10.895 mPa-s and F2 0.894 mPa-s than the other formulations. The particle size distribution of the nanosuspension with zeta potential found to be negative mv. Fourier transform infrared spectroscopy indicated that there was no possible interaction between drug and polymer.Conclusion: From this study, it was concluded that in recent advances in novel drug delivery system aims to enhance safety and efficacy of drug molecule by formulating a convenient dosage form for administration and to achieve better patient compliance, one such approach is nanosuspension.

scholarly journals FORMULATION AND EVALUATION OF LUMEFANTRINE CAPSULE PREPARED BY USING LIQUISOLID TECHNIQUE

2018 ◽  
Vol 10 (2) ◽  
pp. 43 ◽  
Author(s):  
Amreen Khan ◽  
Shikha Agrawal
Keyword(s):  
Uv Spectroscopy ◽  
Research Work ◽  
Amorphous State ◽  
Tween 80 ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Buffer Solution ◽  
Capsule Formulation ◽  
Promising Alternative ◽  
Drug Sample

Objective: The objective of present research work was to formulate and evaluate of Lumefantrine capsule by using novel liquisolid technique to give increased dissolution rate of poorly water-soluble drug Lumefantrine.Methods: Formulation of lumefantrine capsule using drug solution and suspension method was used. Different liquisolid formulations were prepared using a mathematical model for calculating required quantities of powder and liquid ingredients to produce an acceptably flowable and compressible admixture. Liquisolid capsule formulation F-1 to F-9 were prepared by using different type and different concentration of non-volatile solvent like PEG-400, Tween 80, propylene glycol and avicels, aerosil as carrier and coating material respectively.Results: The liquisolid formulation were within the acceptable limits and drug release rates of all prepared liquisolid were distinctly higher as compared to pure drug. Lumefantrine shows maximum solubility in tween 80 as a non-volatile solvent. All the preformulation parameters were evaluated such as organoleptic characterization of the drug sample, melting point, pH, identification of drug samples by using UV spectroscopy and FTIR analytical method, preparation of calibration curves, solubility studies of drug sample like qualitative, quantitative and pH-dependent solubility of the drug in a buffer solution of different pH. They were further processed for solid-state characterization such as, DSC and SEM and the results confirmed the transformation of native crystalline nature of drug to an amorphous state. FTIR analysis also confirmed no drug-excipient interaction. Liquisolid formulations showed improved in vitro dissolution behaviour of lumefantrine over that of pure drug.Conclusion: From this study, it was concluded that liquisolid method is a promising alternative for improvement of dissolution property of water-insoluble drugs.

Effect of CMP Pad Exposure to Aqueous Media on the Pad Properties. Part 1. Dynamic Mechanical and Modulated DSC Analysis

2002 ◽  
Vol 732 ◽  
Author(s):  
A. Tregub ◽  
M. Moinpour ◽  
J. Sorooshian
Keyword(s):  
Aqueous Media ◽  
Mechanical Analysis ◽  
Fickian Diffusion ◽  
Modulated Dsc ◽  
Buffer Solution ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Ph Buffer Solution ◽  
Ph Buffer

AbstractSoaking of polyurethane-based CMP pad in oxide slurry, de-ionized water, and pH buffer solution, and its effect on thermal and mechanical properties of the pads was studied using Dynamic Mechanical Analysis and Modulated Differential Scanning Calorimetry. Pad softening due to soaking was established, and softening mechanisms are discussed. Diffusion of the aqueous medias to polyurethane pad was described using Fickian diffusion model.

scholarly journals Effect of Interface Layer Capacitance on Polydimethylsiloxane in Electrowetting-on-Dielectric Actuation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Shiraz Sohail ◽  
Soumen Das ◽  
Karabi Biswas
Keyword(s):  
Biomedical Applications ◽  
Debye Length ◽  
Interface Layer ◽  
Vital Role ◽  
Experimental Result ◽  
Buffer Solution ◽  
Electrowetting On Dielectric ◽  
Ph Buffer Solution ◽  
Ph Buffer ◽  
Dielectric Actuation

Electrowetting is an effective way to manipulate small volume of liquid in microfluidic applications. It has been sophisticatedly used in the fields of Lab-on-a-Chip (LoC) devices, optics, biomedical applications, and electronic paper (e-paper). Generally, Young-Lippmann (Y-L) equation is used to relate the mechanical and electrical force involved in electrowetting-on-dielectric (EWOD) based actuation. And the general trend is to neglect the effect of double layer capacitance formed at the metal-liquid interface considering the Debye-length to be in the order of nanometer. But, at electrode-electrolyte-insulator interface, the effect of interface layer capacitance becomes significant and often leads to the mismatch between the experimental observation and theoretical result. In this work, the surface behaviour of polydimethylsiloxane (PDMS) for EWOD application is studied experimentally and a term “k” has been introduced in the Y-L equation to match the theoretical and experimental result. Effect of interface layer capacitance has been observed in contact angle versus applied voltage experiment with different pH buffer solution. The introduction of “k” term takes care of the interface layer capacitance which can not be neglected and plays a vital role when the applied electric potential is high.

Electrical Characteristics of the Concentric-Shape Carbon Nanotube Network Device in pH Buffer Solution

2010 ◽  
Vol 57 (10) ◽  
pp. 2684-2689 ◽  
Author(s):  
Jun Ho Cheon ◽  
Jaeheung Lim ◽  
Sung Min Seo ◽  
Jun-Myung Woo ◽  
Seok Hyang Kim ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Electrical Characteristics ◽  
Buffer Solution ◽  
Carbon Nanotube Network ◽  
Ph Buffer Solution ◽  
Ph Buffer ◽  
Network Device

Preparation and Characterization of Thermo-Sensitive Hydroxypropylmethyl Cellulose/Poly (N-Isopropylacrylamide) Hydrogel

2011 ◽  
Vol 194-196 ◽  
pp. 773-776 ◽  
Author(s):  
Yu Liang Xiao ◽  
Cheng Cai Xia ◽  
Gui Yun Duan ◽  
Xiao Dong Zhao
Keyword(s):  
Response Rate ◽  
Weight Ratio ◽  
Methyl Cellulose ◽  
Chemical Compositions ◽  
Swelling Ratio ◽  
Buffer Solution ◽  
Temperature Changes ◽  
Swelling Rate ◽  
Increasing Temperature

The best is to read these instructions and follow the outline of this text. Thermo-sensitive hydrogels based on linear HPMC and cross-linked PNIPAAm were prepared by the semi-IPN technique. The interior morphology of hydrogels was investigated by fluorescent microscope. The hydrogels were characterized by Fourier transform infrared (FTIR). The thermo-sensitivity, equilibrium swelling rate and swelling dynamics of these hydrogels were investigated. The chemical compositions and structures of the semi-hydrogels were similar to each other, as measured by FTIR. The results indicated that the swelling ratio of the hydrogel decreased with increasing temperature. In pH 7.4 buffer solution (37°C ), when the weight ratio of HPMC to NIPAAm was 1/100, the swelling ratio was the maximum. In comparision with a conventional PNIPA hydrogel, the semi-IPN hydrogel synthesized with hydroxypropyl-methyl cellulose exhibits a much faster response rate to temperature changes. For example, PNI-H05 loses 87% water within 5min, whereas the conventional hydrogel loses only about 25% water within 5 min. and about 50% water within 50 min.

scholarly journals Biological macromolecule chitosan grafted co-polymeric composite: bio-adsorption probe on cationic dyes

2021 ◽  
Author(s):  
Shyam R. Khairkar ◽  
Shubham V. Pansare ◽  
Amol A. Shedge ◽  
Shraddha Chhatre ◽  
Dnyaneshwar K. Kulal ◽  
...  
Keyword(s):  
Monomer Concentration ◽  
Polymeric Composite ◽  
Sorption Process ◽  
Vinyl Monomer ◽  
Grafted Polymers ◽  
Biological Macromolecule ◽  
Buffer Solution ◽  
Toxic Dyes ◽  
Ph Buffer Solution ◽  
Ph Buffer

AbstractChitosan biological macromolecule is a versatile polymer; chemical modification has been carried out that lead to the formation of chitosan grafted polymers composites (Chito-g-PC). We proposed synthesis of six various Chito-g-PC as sorbents for toxic dyes. A novel graft copolymerization method based on radical polymerization with vinyl monomer like acrylic acid, acrylamide, N-isopropylacrylamide, methacrylic acid and polyacrylonitrile were utilized in order to address the large amount of swelling at four different pH buffers solution. The effect of initiator and monomer concentration, time and temperature on % grafting and % grafting efficiency were performed. Comparative characterization of Chito and Chito-g-PC were evaluated by SEM, XRD and FTIR, as well as solubility characteristics of the composites were determined by various pH buffer solution. Cationic toxic dyes Malachite green (MG) and Methylene blue (MB) were selected as the sorbet, and Chito-g-PC were used as biosorbents. Thermodynamic analysis showed that the sorption process was spontaneous and endothermic with an increased randomness. The sorption experiments were realized with six different Chito-g-PC for MG and MB at various pH.

Determination of the pH sensitivity level of anodized Ta2O5 nanotubular using pH buffer solution: Towards engine oil deterioration sensor

2021 ◽  
Author(s):  
Nur Lili Suraya Ngadiman ◽  
Rozina Abdul Rani ◽  
Zulasyraf Farhan Zulkifli ◽  
Muhammad Firdaus Abdullah ◽  
Siti Rabizah Makhsin ◽  
...  
Keyword(s):  
Ph Sensitivity ◽  
Engine Oil ◽  
Buffer Solution ◽  
Oil Deterioration ◽  
Sensitivity Level ◽  
Ph Buffer Solution ◽  
Ph Buffer

Kinetic Study of Desulfonation of Disulfonated Alkyl Diphenyloxide Surfactants

1982 ◽  
Vol 22 (06) ◽  
pp. 993-997
Author(s):  
R.C. Marriott ◽  
C.I. Kao ◽  
F.W. Kristal
Keyword(s):  
Half Life ◽  
Hydrogen Ion ◽  
Effect Of Temperature ◽  
Oil Reservoir ◽  
Acid Form ◽  
Buffer Solution ◽  
Ph Buffer Solution ◽  
Ph Buffer ◽  
The Stability ◽  
Ph Range

Abstract Kinetic study of the desulfonation of Dowfax surfactants, disulfonated alkyl diphenyloxide, is carried out in the temperature range of from 177 to 272C, and a pH range of 2.0 to 7.0. The rate data support that the desulfonation is a step-wise reaction catalyzed by hydrogen ion. The desulfonation rate is first-order with respect to both surfactant and hydrogen ion concentrations. As a result, the pH of the reaction system has a very significant effect on the stability of the surfactants and may outweigh the effect of temperature. The half-life of disulfonated alkyl diphenyloxide at 235C in a 5.5-pH buffer solution is 1,035 days, and at 272C in a 7.0-pH buffer solution is 295 days. The results indicate that these surfactants can be used in most oil reservoir steamflood applications, especially when the rock formation may buffer the pH to about 7.0. Introduction These surfactants are a mixture of mono- and dialkylated, essentially disulfonated diphenyloxide. The materials are sold commercially either in acid form (pH less than 1.0) or mostly in neutralized form (pH >7) as surfactants for various applications. These surfactants commonly are used in harsh environments such as high temperature, high electrolyte concentration, and wide pH range. The stability of these surfactants has not been studied extensively. Handy et al. evaluated several surfactants for oil-reservoir application. Dowfax 2AO (the acid form) was one of the surfactants they studied. Their data, for 177C and a pH ranging from 3.3 to 3.9, indicate that the desulfonation follows first-order kinetic with a half-life of 5.63 days. Since the pH in most carbonate reservoirs will be buffered to approximately 7 pH, Handy et al. also studied the effect of pH using a petroleum sulfonate, Petronate TRS-10-80. Buffering the material to a pH of 7.04 only marginally improves the half-life from 7 to 10 days. Consequently, they concluded that none of the surfactants tested would perform adequately in the steamflood oil-reservoir applications. perform adequately in the steamflood oil-reservoir applications. It is generally believed that the desulfonation of aromatic sulfonates proceeds by an initial rapid protonation of the aromatic ring followed by a proceeds by an initial rapid protonation of the aromatic ring followed by a rate-limiting desulfonation step to release a mole of sulfuric acid. The reaction depends significantly on the hydrogen ion concentration. Since the desulfonation releases sulfuric acid and decreases the pH of the system, an autocatalytic phenomenon can be expected. The kinetics of the desulfonation of disulfonated alkyl diphenyloxide and the effect of temperature and a wide range of pH on the desulfonation rate are discussed in this paper. Experimental The analyses of the two forms of disulfonated alkyl diphenyloxide, the acid form and the sodium salt form, are shown in Table 1. Both of these forms contain C 12 branched hydrophobes. The desulfonation experiments were carried out in tantalum vessels approximately 9 cm3 in volume. The vessels were purged first with nitrogen for 5 minutes. The surfactants were diluted to the appropriate concentration and were adjusted to the desired pH. SPEJ p. 993

SIMULTANEOUS MEASUREMENT OF DOPAMINE AND ASCORBIC ACID AT CNT ELECTRODE

2005 ◽  
Vol 19 (01n03) ◽  
pp. 607-610 ◽  
Author(s):  
C. G. HU ◽  
W. L. WANG ◽  
B. FENG ◽  
H. WANG
Keyword(s):  
Ascorbic Acid ◽  
Carbon Nanotube ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
High Sensitivity ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Electrochemical Behaviors ◽  
Ph Buffer Solution ◽  
Ph Buffer

Electrochemical behaviors of dopamine and ascorbic acid have been studied at the carbon nanotube electrode using cyclic voltammetry. Electrocatalysis has been found for dopamine redox reactions at the carbon nanotube electrode in comparison with the glassy carbon electrode. A well-defined oxidative peak for ascorbic acid was observed at the carbon nanotube electrode with the peak potential negative shift versus the glassy carbon electrode. The important discover was that the carbon nanotube electrode can be used to detect low level of dopamine selectively with high sensitivity in the presence of a large excess of ascorbic acid in the acidic media and in the physiological pH buffer solution as well.

Simultaneous Measurement of Epinephrine and Ascorbic Acid at the Carbon Nanotube Electrode

2005 ◽  
Vol 23 ◽  
pp. 305-308 ◽  
Author(s):  
C.G. Hu ◽  
W.L. Wang ◽  
K.J. Liao ◽  
Y.T. Wang
Keyword(s):  
Ascorbic Acid ◽  
Carbon Nanotube ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
High Sensitivity ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Electrochemical Behaviors ◽  
Ph Buffer Solution ◽  
Ph Buffer

Electrochemical behaviors of epinephrine and ascorbic acid have been studied at the carbon nanotube electrode using cyclic voltammetry. Electrocatalysis has been found for epinephrine redox reactions at the carbon nanotube electrode in the comparison with the glassy carbon electrode. A well-defined oxidative peak for ascorbic acid was observed at the carbon nanotube electrode with the peak potential negative shift versus the glassy carbon electrode. Low level of epinephrine can be determined at the carbon nanotube electrode selectively with high sensitivity in the presence of a large excess of ascorbic acid in the acidic media and in the physiological pH buffer solution.

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