scholarly journals Pseudo-zwitterionic microvesicles for sustained urea release

2020 ◽  
Vol 85 (4) ◽  
pp. 493-503
Author(s):  
Iram Bibi ◽  
Tasleem Kousar ◽  
Syed Shah ◽  
Wajid Rehman ◽  
Farman Ali
Keyword(s):  
Binding Free Energy ◽  
Sodium Dodecyl ◽  
Entrapment Efficiency ◽  
Release Mechanism ◽  
Ammonium Bromide ◽  
Visible Absorption ◽  
Catanionic Vesicles ◽  
Urea Release ◽  
Mechanism And Kinetics ◽  
Hexadecyltrimethyl Ammonium Bromide

Zwitterionic microvesicles formed by catanionic system, based on sodium dodecyl sulfate and hexadecyltrimethyl ammonium bromide, have been investigated for sustained urea release using UV?visible absorption spectroscopy. The change in variables such as temperature, sonication time and initial urea concentration was related to urea entrapment efficiency and release from microvesicles. Korsmeyer?Peppas model was applied to highlight release mechanism and kinetics. Both diffusion and erosion were responsible for urea release and rate constant varied with change in conditions. The quantification of association between urea and catanionic vesicles in terms of binding constant (Kbin) and binding free energy showed that urea binding was thermodynamically favored. Our results indicate that biocompatible pseudo-zwitterionic vesicles have enormous potential to act as sustained release system for nitrogenous fertilizers such as urea.

Formulation and In Vivo Evaluation of Mucoadhesive Micro-spheres of Rebamipide, a Mucoprotective Drug for GIT Disorders

2018 ◽  
Vol 11 (3) ◽  
pp. 4089-4097
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Kanteepan P
Keyword(s):  
Drug Release ◽  
Entrapment Efficiency ◽  
In Vivo Studies ◽  
Amino Acid Derivative ◽  
Release Mechanism ◽  
In Vivo Evaluation ◽  
In Vitro Drug Release ◽  
Percentage Yield

Rebamipide, an amino acid derivative of 2-(1H)-quinolinone, is used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. The current research study aimed to develop novel gastro-retentive mucoadhesive microspheres of rebamipide using ionotropic gelation technique. Studies of micromeritic properties confirmed that microspheres were free flowing with good packability. The in vitro drug release showed the sustained release of rebamipide up to 99.23 ± 0.13% within 12 h whereas marketed product displayed the drug release of 95.15 ± 0.23% within 1 h. The release mechanism from microspheres followed the zero-order and Korsmeyer-Peppas (R2 = 0.915, 0.969), respectively. The optimized M12 formulation displayed optimum features, such as entrapment efficiency 97%, particle size 61.94 ± 0.11 µm, percentage yield 98%, swelling index 95% and mucoadhesiveness was 97%. FTIR studies revealed no major incompatibility between drug and excipients. SEM confirmed the particles were of spherical in shape. Optimized formulation (M12) were stable at 40°C ± 2°C/75% RH ± 5% RH for 6 months. In vivo studies were performed and kinetic parameters like Cmax, Tmax, AUC0-t, AUC0-∞, t1/2, and Kel  were calculated. The marketed product Cmax (3.15 ± 0.05 ng/mL) was higher than optimized formulation (2.58 ± 0.03 ng/mL). The optimized formulation AUC0-t (15.25 ± 1.14 ng.hr/mL), AUC0-∞ (19.42 ± 1.24 ng.hr/mL) was significantly higher than that of marketed product AUC0-t (10.21 ± 1.26 ng.hr/mL) and AUC0-∞ (13.15 ± 0.05 ng.hr/mL). These results indicate an optimized formulation bioavailability of 2.5-fold greater than marketed product.  

Influence of Different Dispersants on the Dispersion Property of Nano-Aluminium Powders

2011 ◽  
Vol 71-78 ◽  
pp. 122-125 ◽  
Author(s):  
Ling Li Song ◽  
Ren Yuan Zhang ◽  
Ling Bo Mao ◽  
Wen Jie Zhu ◽  
Miao Yan Zheng
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Ultrasonic Vibration ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Sodium Dodecyl ◽  
Dispersion Property ◽  
Ammonium Bromide ◽  
Aluminum Powders ◽  
Ultrasonic Time ◽  
Dodecyl Sulfate ◽  
Cetyl Trimethyl Ammonium

The influences of dispersant type, supersonic time and concentration on the dispersion property of the nano-aluminium powders in glycol water were systematically studied by using Sodium dodecyl sulfate (SDS)，cetyl trimethyl ammonium bromide (CTAB) and sodium hexa metah posphate（SHMP）as dispersants. During the first stage of the experiments, influences of dispersant type and ultrasonic time with these dispersants were evaluated. The next stage of the study was focused on SHMP concentration. The influence of SHMP concentration was assessed. The results show that with the increasing of ultrasonic time, the dispersion property of nano-aluminum powders first increases and then decreases, and SHMP is the best one. The excellent dispersing condition on the dispersion property of nano-aluminium is: 5g/L SHMP and 50 min ultrasonic vibration.

Spontaneous Formation of DTAB/SDBS Vesicles

2013 ◽  
Vol 734-737 ◽  
pp. 2505-2508
Author(s):  
Lin Lin Cui ◽  
Hua Nan Guan
Keyword(s):  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Ammonium Bromide ◽  
Benzene Sulfonate ◽  
Complex Formulation ◽  
Structure And Morphology ◽  
Spontaneous Formation ◽  
Dodecyl Benzene Sulfonate ◽  
Dodecyl Trimethyl Ammonium Bromide ◽  
The Stability

Dodecyl trimethyl ammonium bromide/sodium dodecyl benzene sulfonate (DTAB/SDBS) complex formulation of scale effect on the spontaneous formation of vesicles and the influence of different factors on the stability of vesicles were discussed, structure and morphology of vesicles were observed.

Effect of detergents and chemicals on purified vaccinia virus: analysis by SDS polyacrylamide gel electrophoresis and electron microscopy

1977 ◽  
Vol 23 (3) ◽  
pp. 240-252 ◽  
Author(s):  
J. Boisvert ◽  
T. Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Vaccinia Virus ◽  
Gel Electrophoresis ◽  
Alkali Treatment ◽  
Guanidine Hydrochloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Ammonium Bromide ◽  
Molecular Weights ◽  
Viral Particles

Vaccinia virus particles were dissociated into their constituent polypeptides and analysed by sodium dodecyl sulfate (SDS) gel electrophoresis. Thirty-three distinct polypeptide bands were identified and their molecular weights ranged between 11 000 and 150 000 daltons.Specific staining of gels containing polypeptides of dissociated virions revealed the presence of eight glycopeptides. No lipopeptides were detected.Analysis of chemical extracts (urea, guanidine hydrochloride, and alkali treatment) of the virus by SDS gel electrophoresis indicated that a total of 10 to 14 different polypeptides ranging in molecular weights from 11 000 to 70 000 daltons were solubilized.Analysis of detergent extracts and of the remains of extracted viral particles has shown that the detergent Nonidet P-40 (NP-40) solubilized a total of 11 polypeptides of which 6 were glycopeptides. The other detergents sodium deoxycholate (SDC) and cetyl trimethyl ammonium bromide (CTAB) were not as selective, both solubilizing more than 25 of the polypeptides composing the virus. Gel electrophoresis results also indicated that most of the small molecular weight (11 000–70 000 daltons) polypeptides were readily solubilized by NP-40, SDC, and CTAB, while those with molecular weights of 70 000 daltons and higher were not well solubilized.The effects of detergents were also analysed by electron microscopy. Evidence was obtained for subpopulations of viral particles having different susceptibility to detergent extraction.

Mobility of DR1 Molecules Embedded in Nanostructured PMMA Films

2009 ◽  
Vol 5 ◽  
pp. 135-142
Author(s):  
Jorge A. García-Macedo ◽  
A. Franco ◽  
Guadalupe Valverde-Aguilar ◽  
M.A. Ríos-Enríquez
Keyword(s):  
Second Harmonic ◽  
Sodium Dodecyl ◽  
Orientation Distribution ◽  
Decay Rates ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Poling Field ◽  
Different Temperatures ◽  
Cetyl Trimethyl Ammonium ◽  
Kinetics Of

The kinetics of the orientation of Disperse Red 1 (DR1) molecules embedded in nanostructured Polymethylmetacrylate (PMMA) films was studied under the effect of an intense constant electric poling field. The changes in the orientation distribution of the DR1 molecules were followed by Second Harmonic Generation (SHG) measurements. The SHG signal was recorded as function of time at three different temperatures. We focused on both, the signal increases under the presence of the poling field and the signal decays without the poling field. The studied PMMA films were nanostructured by the incorporation of ionic surfactants as the Sodium Dodecyl Sulfate (SDS) and the Cetyl Trimethyl Ammonium Bromide (CTAB) during their preparation. The kinds of nanostructures obtained in the films were determined by means of X-ray diffraction (XRD) measurements. Substantial differences in signal intensity and in growth and decay rates between amorphous and nanostructured films were found.

The Study of Surfactant Effect on Soil Water Infiltration

2011 ◽  
Vol 361-363 ◽  
pp. 1946-1949
Author(s):  
Yi Fei Li ◽  
Tian Wei Qian ◽  
Li Juan Huo
Keyword(s):  
Hydraulic Conductivity ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Saturated Hydraulic Conductivity ◽  
Water Infiltration ◽  
Ammonium Bromide ◽  
Soil Infiltration ◽  
Soil Water Infiltration ◽  
Dodecyl Benzene Sulfonate ◽  
Cetyl Trimethyl Ammonium

In this paper,the effect of surfactant to the infiltration and the change of saturated hydraulic conductivity was studied by GUELPH PERMEAMETER. We investigated effects on soil infiltration by three representative surfactants.The results show that the existing of sodium dodecyl benzene sulfonate (SDBS), cetyl trimethyl ammonium bromide bromide (CTAB) and polyxyethylene fatty alcohol (AEO9) would decrease soil saturated hydraulic conductivity.

scholarly journals Chitosan/Sodium Dodecyl Sulfate Complexes for Microencapsulation of Vitamin E and Its Release Profile—Understanding the Effect of Anionic Surfactant

2021 ◽  
Vol 15 (1) ◽  
pp. 54
Author(s):  
Jelena Milinković Budinčić ◽  
Lidija Petrović ◽  
Ljiljana Đekić ◽  
Milijana Aleksić ◽  
Jadranka Fraj ◽  
...  
Keyword(s):  
Vitamin E ◽  
Sodium Dodecyl Sulfate ◽  
Anionic Surfactant ◽  
Sodium Dodecyl ◽  
Pharmaceutical Products ◽  
Release Mechanism ◽  
Bioactive Substances ◽  
Water Emulsion ◽  
Dodecyl Sulfate

Microencapsulation of bioactive substances is a common strategy for their protection and release rate control. The use of chitosan (Ch) is particularly promising due to its abundance, biocompatibility, and interaction with anionic surfactants to form complexes of different characteristics with relevance for use in microcapsule wall design. In this study, Ch/sodium dodecyl sulfate (SDS) microcapsules, without and with cross-linking agent (formaldehyde (FA) or glutaraldehyde (GA)), were obtained by the spray drying of vitamin E loaded oil-in-water emulsion. All of the microcapsules had good stability during the drying process. Depending on the composition, their product yield, moisture content, and encapsulation efficiency varied between 11–34%, 1.14–1.62%, and 94–126%, respectively. SEM and FTIR analysis results indicate that SDS as well as cross-linkers significantly affected the microcapsule wall properties. The profiles of in vitro vitamin E release from the investigated microcapsules fit with the Korsmeyer-Peppas model (r2 > 0.9). The chemical structure of the anionic surfactant was found to have a significant effect on the vitamin E release mechanism. Ch/SDS coacervates may build a microcapsule wall without toxic crosslinkers. This enabled the combined diffusion/swelling based release mechanism of the encapsulated lipophilic substance, which can be considered favorable for utilization in food and pharmaceutical products.

scholarly journals PACKAGING OF HEPATITIS B SURFACE ANTIGEN VACCINE AND MORINGA OLEIFERA EXTRACT INTO CHITOSAN NANOPARTICLES

2019 ◽  
Vol 12 (1) ◽  
pp. 346
Author(s):  
Diky Mudhakir ◽  
Adik Ahmadi ◽  
Muhamad Insanu ◽  
Neny Nuraini
Keyword(s):  
Immune Response ◽  
Particle Size ◽  
Hepatitis B ◽  
Surface Antigen ◽  
Moringa Oleifera ◽  
Hepatitis B Surface Antigen ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Chitosan Nanoparticles ◽  
Entrapment Efficiency

Objective: Oftentimes, the recombinant antigen for the use of vaccines is less immunogenic than live attenuated or inactive vaccines. Hence, a potent adjuvant is needed to enhance the immune response. Moreover, the role of vector design is also important to facilitate the improvement of the immune response. The aim of this research was to develop hepatitis B surface antigen (HBsAg)-loaded nanoparticles and Moringa oleifera aqueous leaf extracts as an adjuvant using chitosan polymer. Methods: Chitosan nanoparticles were prepared by the ionic gelation method using sodium tripolyphosphate as the cross-linking agent. A system was composed of chitosan core in which HBsAg and M. oleifera extracts were incorporated. The concentration of HBsAg used in this combination was 10 μg/ml, and the concentrations of extracts were 10, 50, and 100 μg/ml, respectively. In this study, three types of nanoparticles were produced: HBsAg-loaded nanoparticles, M. oleifera-loaded nanoparticles, and combination of HBsAg–M. oleifera-loaded nanoparticles. The nanoparticles formed were characterized by the particle size, HBsAg entrapment efficiency using sodium dodecyl sulfate polyacrylamide gel electrophoresis, and the entrapment efficiency of extracts using the total flavonoid method. Results: The results showed that the particle size was between 111 and 245 nm. The entrapment efficiency of HBsAg in the separate formula was 79%, while that in the combined formula was approximately 96–98%. Furthermore, the entrapment efficiency of the extracts in the separate formula was around 64–91%, while that in the combined formula was 55–82.5%. Particularly, HBsAg–M. oleifera-loaded chitosan nanoparticles with the extract concentrations of 50 μg/ml showed the highest entrapment efficiencies of HBsAg and M. oleifera extracts of approximately 98 and 82.5%, respectively. Conclusion: Collectively, the system has been successfully developed, so it is then plausible to determine the function of the devices to enhance the immune response in the future.

ROSUVASTATIN CALCIUM NANOSPONGES IN THE FORMULATION OF EXTENDED RELEASE TABLETS

INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (10) ◽  
pp. 25-33
Author(s):  
Satya Lakshmi S. ◽  
Jyothsna P ◽  
Srinivasa Rao Y. ◽  
Naga Mallikarjun P. ◽  
Keyword(s):  
Drug Release ◽  
Extended Release ◽  
Release Kinetics ◽  
Entrapment Efficiency ◽  
Release Mechanism ◽  
Testing Procedures ◽  
Drug Substances ◽  
Diffusion Technique ◽  
Poorly Soluble ◽  
Rosuvastatin Calcium

Cyclodextrin has been recognized as a linker molecule that can link with the various drug substances to produce a nano-porous structure called nanosponges (NS) and increase the dissolution rate of poorly soluble drug substances. This work aimed to load rosuvastatin calcium (RSC) with solubility enhancer’s β-cyclodextrin (β-CD) or polyvinyl alcohol (PVA). β-CD based RSC-NS were fabricated by the emulsion solvent diffusion technique; with solubilizer dichloromethane and different ratios of ethyl cellulose as a co-polymer. Characterization of the prepared nanosponges was done by various testing procedures that confirm its nanosize and particle size and drug release. RSC loading in NS was assessed by DSC, FTIR and SEM. Among all the formulations F5 has 78.23 % entrapment efficiency. 2-3 folds of increased solubility were obtained with RSC-NS. F1-F6 formulations released 76.35 % - 98.69 % of the drug at the end of 30 min. In the preparation of extended-release tablets, NS prepared from F5 formulation was used and the best tablet formulation was selected based on various evaluation tests. All the formulations except S3, S8 followed first-order release kinetics. S1 & S2 drug release mechanism is Higuchi while other formulations are Korsemeyer-Peppas, so the release mechanism for most of the formulations is erosion than diffusion.

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