Nanoparticle Assembly in High Polymer Concentration Solutions Increases Superlattice Stability

Although radiation damage is the limiting factor in HREM of polymers, new techniques based on low dose imaging at low magnification have permitted lattice images to be obtained from very radiation sensitive polymers such as polyethylene (PE). This paper describes the computer averaging of P4MP1 lattice images. P4MP1 is even more sensitive than PE (total end point dose of 27 C m-2 as compared to 100 C m-2 for PE at 120 kV). It does, however, have the advantage of forming flat crystals from dilute solution and no change in d-spacings is observed during irradiation.Crystals of P4MP1 were grown at 60°C in xylene (polymer concentration 0.05%). Electron microscopy was performed with a Philips EM 400 T microscope equipped with a Low Dose Unit and operated at 120 kV. Imaging conditions were the same as already described elsewhere. Enlarged micrographs were digitized and processed with the Spider image processing system.

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Preparation and In-vitro Evaluation of Fe3O4 Encapsulated by Chitosan Loaded Capecitabine Nanoparticles for the Treatment of Breast Cancer

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v6i3.8888 ◽

2016 ◽

Vol 6 (3) ◽

Author(s):

Shanmuganathan S. ◽

Nigma S. ◽

Anbarasan B. ◽

Harika B.

Keyword(s):

Fe3o4 Nanoparticles ◽

Polymer Concentration ◽

In Vitro Release ◽

Entrapment Efficiency ◽

In Vitro Evaluation ◽

Sem Image ◽

Therapeutic Molecules ◽

Dialysis Method ◽

Vitro Release

Nanoparticulate Carriers which is biodegradable, biocompatible and bio adhesive have significant feasible applications for administration of therapeutic molecules. The present study was aimed to formulate and optimise Capecitabine loaded Chitosan-Fe3O4 Nanoparticles and to study the in-vitro evaluation by sigma dialysis method. Capecitabine loaded chitosan – Fe3O4 nanoparticles batches with different ratios of drug: polymer (1:1, 1:2, 1:3, 1:4, 1:5, 1:6) were prepared by ionic gelation method. Increase in polymer concentration increases the nanoparticle drug content. Entrapment efficiency was 60.12% with drug to polymer ratio F3 (1:3). In-vitro release was found to be 65.20% for 12 hrs. Capecitabine from chitosanFe3O4 nanoparticles SEM image reveals discrete spherical structure and particles with size range of 100-500nm. FTIR studies represent the functional groups present with no characteristics change in formulations. Samples stored at refrigerator conditions showed better stability compared with samples kept at other conditions during 8 weeks of storage.

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Influence of Formulation Variables and Processing Techniques on Drug Release from Carbopol-971 based Matrix Tablets of Cinnarizine and Nimodipine.

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v2i1.8840 ◽

2010 ◽

Vol 2 (1) ◽

Author(s):

Singh K. ◽

Pandit K. ◽

Mishra N.

Keyword(s):

Drug Release ◽

Release Rate ◽

Polymer Concentration ◽

Matrix Tablets ◽

Wet Granulation ◽

Weight Variation ◽

Diffusion Controlled ◽

The Matrix ◽

Processing Techniques ◽

Formulation Variables

The matrix tablets of cinnarizine and nimodipine were prepared with varying ratio of Carbopol- 971P and co-excipients of varying hydrophilicity (i.e. dicalcium phosphate and spray dried lactose) by direct compression and wet granulation using alcoholic mucilage. The prepared tablets were evaluated for weight variation, hardness and friability. The influence of concentration of the matrix forming material and co-excipients on the release rate of the drug was studied. The release rate of Cinnarizine (more soluble drug) from tablets followed diffusion controlled mechanism whereas for nimodipine (less soluble drug), the drug release followed case-II or super case- II transport mechanism based on Korsmeyer- Peppas equation. The results indicated that the drug release from matrix tablets was increases with increase in hydrophilicity of drug and co-excipients. The release of drug also increased with thermal treatment and decreasing polymer concentration.

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POLYMER CONCENTRATION, BRINE SALINITY AND TEMPERATURE EFFECTS ON XANTHAN GUM SOLUTIONS RHEOLOGY – A COMPLEMENTARY AND CHECK-UP STUDY

10.26678/abcm.cobem2019.cob2019-2215 ◽

2019 ◽

Author(s):

Edgar Javier Rueda Rueda ◽

Rosangela Moreno

Keyword(s):

Temperature Effects ◽

Xanthan Gum ◽

Polymer Concentration ◽

Brine Salinity

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Multilayer Polymeric Nano composite Membrane for Oxygen Separation

Bulletin of Scientific Research ◽

10.34256/bsr1921 ◽

2019 ◽

Vol 1 (2) ◽

pp. 1-11

Author(s):

Gobi Nallathambi ◽

Hazel Dhinakaran

Keyword(s):

Polymer Concentration ◽

Sio2 Nanoparticles ◽

Air Separation ◽

Regression Equations ◽

Permeate Flux ◽

Nano Composite ◽

Box Behnken Design ◽

Oxygen Selectivity ◽

Multilayer Membrane ◽

Spun Fiber

Air separation is a process of separating primary components from the atmospheric air. Development of membrane technologies plays a key role in air separation. Multi-layer polymeric nanocomposite membranes have been developed by a novel technique using Polyacrylonitrile (PAN) and cellulose acetate (CA) along with nano silica particles (SiO2) to obtain a higher oxygen selectivity and permeability. For the construction of the multilayer membrane, the Box-Behnken design has been used by employing three independent variables namely PAN Electro spinning time, the SiO2 percentage in the PAN polymer and CA/PEG polymer concentration. The developed membranes have been characterized for its surface morphology and physical properties. Along with the analysis of compound desirability, the results were also subject to statistical analysis in order to form regression equations. The electro spun fiber diameter increases along with the concentration of SiO2 nanoparticles and the range is from 50 nm to 400 nm. Moreover, the maximum pore size on the surface of the membrane lies between 200 to 400 nm whereas the maximum percentage of oxygen purity obtained is 48 with the permeate flux of 5.45 cm3/cm2/min.

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Preparation and Evaluation of Gemifloxacin Mesylate Floating Matrix Tablets in Healthy Human Volunteers

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2017.10.1.8 ◽

2017 ◽

Vol 10 (1) ◽

pp. 3623-3630

Author(s):

Bhikshapathi D. V. R. N. ◽

Haarika B ◽

Jyothi Sri S ◽

K Abbulu

Keyword(s):

Drug Release ◽

Sodium Bicarbonate ◽

Polymer Concentration ◽

Hydroxypropyl Methylcellulose ◽

Matrix Tablets ◽

Physical Parameters ◽

Drug Bioavailability ◽

Floating Tablets

The purpose of present investigation was to develop floating matrix tablets of gemifloxacin mesylate, which after oral administration could prolong the gastric residence time, increase the drug bioavailability and diminish the side effects of irritating drugs. Tablets containing drug, various viscosity grades of hydroxypropyl methylcellulose such as HPMC K4M and HPMC K15M as matrix forming agent, Sodium bicarbonate as gas-forming agent and different additives were tested for their usefulness in formulating gastric floating tablets by direct compression method. The physical parameters, in vitro buoyancy, release characteristics and in vivo radiographic study were investigated in this study. The gemifloxacin mesylate floating tablets were prepared using HPMC K4M polymer giving more sustained drug release than the tablet containing HPMC K15M. All these formulations showed floating lag time of 30 to 47 sec and total floating time more than 12 h. The drug release was decreased when polymer concentration increases and gas generating agent decreases. Formulation that contains maximum concen-tration of both HPMC K15M and sodium bicarbonate (F9) showing sufficiently sustained with 99.2% of drug release at 12 h. The drug release from optimized formulation follows Higuchi model that indicates the diffusion controlled release. The best formulation (F9) was selected based on in vitro characteristics and used in vivo radiographic studies by incorporating barium sulphate as a radio-opaque agent and the tablet remained in the stomach for about 6 h.

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