Storage of Hydrophobic Polymers in Bacteria

2019 ◽  
pp. 483-507 ◽  
Author(s):  
Luísa S. Serafim ◽  
Ana M. R. B. Xavier ◽  
Paulo C. Lemos
Keyword(s):  
Hydrophobic Polymers

Formulation Development and Characterization of controlled release core in cup matrix tablets of venlafaxine HCl

2020 ◽  
Vol 15 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Vikas Jhawat ◽  
Gandhi Sivaraman ◽  
Om Prakash Sunnapu ◽  
Ramya Krishna Nakkala ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Zero Order ◽  
Water Soluble ◽  
Matrix Tablets ◽  
Drug Dissolution ◽  
Crystalline Cellulose ◽  
Hydrophobic Polymers

Background: Venlafaxine HCl is a selective serotonin reuptake inhibitor which is given in the treatment of depression. The delivery of the drug at a controlled rate can be of great importance for prolonged effect. Objective: The objective was to prepare and optimize the controlled release core in cup matrix tablet of venlafaxine HCl using the combination of hydrophilic and hydrophobic polymers to prolong the effect with rate controlled drug release. Methods: The controlled release core in cup matrix tablets of venlafaxine HCl were prepared using HPMC K5, K4, K15, HCO, IPA, aerosol, magnesium sterate, hydrogenated castor oil and micro crystalline cellulose PVOK-900 using wet granulation technique. Total ten formulations with varying concentrations of polymers were prepared and evaluated for different physicochemical parameters such FTIR analysis for drug identification, In-vitro drug dissolution study was performed to evaluate the amount of drug release in 24 hrs, drug release kinetics study was performed to fit the data in zero order, first order, Hixson–crowell and Higuchi equation to determine the mechanism of drug release and stability studies for 3 months as observed. Results: The results of hardness, thickness, weight variation, friability and drug content study were in acceptable range for all formulations. Based on the In vitro dissolution profile, formulation F-9 was considered to be the optimized extending the release of 98.32% of drug up to 24 hrs. The data fitting study showed that the optimized formulation followed the zero order release rate kinetics and also compared with innovator product (flavix XR) showed better drug release profile. Conclusion: The core-in-cup technology has a potential to control the release rate of freely water soluble drugs for single administration per day by optimization with combined use of hydrophilic and hydrophobic polymers.

scholarly journals Green Electrospinning of Polymer Latexes: A Systematic Study of the Effect of Latex Properties on Fiber Morphology

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 706
Author(s):  
Edurne Gonzalez ◽  
Aitor Barquero ◽  
Belén Muñoz-Sanchez ◽  
María Paulis ◽  
Jose Ramon Leiza
Keyword(s):  
Systematic Study ◽  
Molar Mass ◽  
Aqueous Dispersion ◽  
Particle Packing ◽  
Fiber Morphology ◽  
Polymer Particles ◽  
Total Solids ◽  
Hydrophobic Polymers ◽  
Safe Technology ◽  
Solids Content

Green electrospinning is a relatively new promising technology in which a polymer (latex) can be spun from an aqueous dispersion with the help of a template polymer. This method is a green, clean and safe technology that is able to spin hydrophobic polymers using water as an electrospinning medium. In this article, a systematic study that investigates the influence of the template polymer molar mass, the total solids content of the initial dispersion and the particle/template ratio is presented. Furthermore, the influence of the surfactant used to stabilize the polymer particles, the surface functionality of the polymer particles and the use of a bimodal particle size distribution on the final fiber morphology is studied for the first time. In green electrospinning, the viscosity of the initial complex blend depends on the amount and molar mass of the template polymer but also on the total solids content of the dispersion to be spun. Thus, both parameters must be carefully taken into account in order to fine-tune the final fiber morphology. Additionally, the particle packing and the surface chemistry of the polymer particles also play an important role in the obtained nanofibers quality.

Heparin release from hydrophobic polymers: (I)In vitro studies

1986 ◽  
Vol 9 (4) ◽  
pp. 193-199 ◽  
Author(s):  
Sung Ho Kim ◽  
Sung Wan Kim
Keyword(s):  
In Vitro Studies ◽  
Hydrophobic Polymers

scholarly journals Surface Modification of Nano-Hydroxyapatite by Coating Stearic Acid

2020 ◽  
Vol 1 (1) ◽  
pp. 1-4
Keyword(s):  
Surface Modification ◽  
Stearic Acid ◽  
Polymeric Matrix ◽  
Gravimetric Analysis ◽  
Polymeric Nanocomposites ◽  
Ceramic Particles ◽  
X Ray ◽  
Hydrophobic Polymers ◽  
Modification Method ◽  
Ceramic Reinforcement

Todays, researchers are challenging with manufacturing polymeric nanocomposites reinforced with ceramic particles due to two inherent properties of ceramic reinforcement particles, particle agglomeration and incompatibility between hydrophilic ceramic particles and hydrophobic polymeric matrix. So in this study, we used nano-Hydroxyapatite (n-HA) as ceramic material and Stearic acid as amphiphilic material for coating n-HA, hydroxysteric acid (SA) surfactant was used for surface coating particles between the hydrophilic HA powders and the hydrophobic polymers. The surface modification and effect of this method were evaluated by by Fourier transformation infrared (FTIR), x-ray diffractometer (XRD), thermal gravimetric analysis (TGA) and Scanning electron microscopy (SEM). The result of FTIR showed that n-HA surfaces were modified successfully and the modification method had the proper grafting amount according to TGA due to this method of modification will be proper for coating reinforcement particles in polymeric matrix.

Polyelectrolyte Coating Provides a Facile Route to Suspend Gold Nanorods in Polar Organic Solvents and Hydrophobic Polymers

2010 ◽  
Vol 2 (12) ◽  
pp. 3417-3421 ◽  
Author(s):  
Alaaldin M. Alkilany ◽  
Lucas B. Thompson ◽  
Catherine J. Murphy
Keyword(s):  
Organic Solvents ◽  
Gold Nanorods ◽  
Hydrophobic Polymers ◽  
Polar Organic Solvents ◽  
Facile Route

Model Folded Hydrophobic Polymers Reside in Highly Branched Voids

2021 ◽  
pp. 183-189
Author(s):  
Khatereh Azizi ◽  
Alessandro Laio ◽  
Ali Hassanali
Keyword(s):  
Hydrophobic Polymers

scholarly journals Development of the Infrared Hollow Waveguide Sampler for the Detection of Chlorophenols in Aqueous Solutions

2002 ◽  
Vol 85 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Jyisy Yang ◽  
Chung-Jay Lee
Keyword(s):  
Aqueous Solutions ◽  
Flow Rate ◽  
Analytical Signal ◽  
Film Coating ◽  
Detection Sensitivity ◽  
Infrared Spectrometry ◽  
Hollow Waveguide ◽  
Fast Detection ◽  
Hydrophobic Polymers ◽  
High Degree

Abstract A method based on the infrared hollow waveguide sampler was developed for sensing chlorophenols in aqueous solutions. This sampler was constructed by coating a suitable hydrophobic film onto the inner surface of an infrared hollow waveguide. By passing the aqueous solution through the hollow waveguide sampler, analytes can be absorbed into the hydrophobic layer. The adsorbed analytes can be sensed later by using Fourier transform infrared spectrometry. Six hydrophobic polymers were investigated for their performance in conjunction with the infrared hollow waveguide sampler for the detection of chlorophenols. Results indicated that poly(acrylonitrile-co-butadiene) was a most suitable hydrophobic material for absorption of chlorophenols in aqueous solutions. To further increase the detection sensitivity, factors such as sampling flow rate, sampling time, and thickness of the hydrophobic film were also investigated. Results indicated that the infrared signals were similar in the examined flow rates (2–30 mL/min), but that a higher flow rate tended to produce a higher analytical signal. Fast detection speed was an advantage of this method for the detection of chlorophenols, and the sampling/detection time can be <10 min. In addition, analytical signals were nearly proportional to the thickness of the hydrophobic film coating the inside of the hollow waveguide. With the optimal conditions found in this work, detection limits based on 3 times the peak-to-peak noise level were around 300 ppb for the chlorophenols examined. A high degree of linearity in the standard curves was also observed for this method in the concentration range of 10–100 ppm. The typical regression coefficients were >0.994 for the chlorophenols examined.

Sign in / Sign up

Export Citation Format

Share Document