Rheological Investigation of Lipid Polymer Hybrid Nanocarriers for Oral Delivery of Felodipine (Conference Paper )#

The rheological behavior among factors that are present in Stokes law can be used to control the stability of the colloidal dispersion system. The felodipine lipid polymer hybrid nanocarriers (LPHNs) is an interesting colloidal dispersion system that is used for rheological characteristic analysis. The LPHNs compose of polymeric components and lipids. This research aims to prepare oral felodipine LPHNs to investigate the effect of independent variables on the rheological behavior of the nanosystem. The microwave-based technique was used to prepare felodipine LPHNs (H1-H9) successfully. All the formulations enter the characterization process for particle size and PDI to ascertain the colloidal properties of the prepared nanosystem then use coaxial rotational digital rheometer for rheological evaluation. The outcomes show that all felodipine LPHNs formulations (H1-H9) had a nanosize and homogenous structure that ascertain colloidal features of the nanodispersion system. The rheogram chart indicates that all of the felodipine LPHNs formulations (H1-H9) show pseudoplastic flow (non-Newtonian flow) that have shear-thinning property. The microwave-based method prepares felodipine LPHNs formulations (H1-H9) that show excellent physical texture that ascertains its ability as a technique for the preparation of nanoparticles. All of the felodipine LPHNs formulations (H1-H9) show pseudoplastic flow that supports the physical stability of the nanosystem.

Electron paramagnetic resonance in organic binder aging in dispersely reinforced substructures

Purpose: To study the intensity of binder aging in organo-mineral mixtures using electron paramagnetic resonance. The aging intensity of the organic binder is provided by its concentration in paramagnetic centers, since asphaltenes are almost one hundred percent of paramagnet concentration and indicate to the aging intensity of the petroleum dispersion system.Approach: Dispersed reinforcement of substructures with chemical fibers made of spent sorbents containing a controlled amount of absorbed oil products allows to partially solve the problem of crack formation and fracture of road pavements designed in accordance with the regulatory documents.Research implications: The service life of substructure made of dispersely reinforced organo-mineral mixtures reduces owing to organic binder aging, which begins at the stage of preparation of organo-mineral mixtures and continues during the substructure operation. Organic binder ageing results in the formation of solvation layers on the surface of mineral materials that become more viscous and brittle.Findings: The substructure dispersed reinforcement with chemical fibers made of spent sorbents containing a controlled amount of absorbed oil products decreases the concentration of paramagnetic centers. This indicates to a decrease in the asphaltene concentration, thereby reducing the aging intensity of the oil dispersion system.

Particle Characterization of Washing Process Effluents by Laser Diffraction Technique

The dominant type of polymer particles in water, sediment, and various organisms partly derives from natural and synthetic fibres released in the washing process. Pollution of aquatic recipients with these particles poses an interdisciplinary problem throughout the world. Wastewater from washing represents a dispersion system with different particle sizes that is also loaded with the source of the particles. Due to this complex system, the qualification and quantification of this type of pollution is difficult. In this paper, the laser diffraction technique was applied to characterize particles in effluents from washing and rinsing materials made of a mixture of cotton and polyester. The results obtained through the analysis prove that the laser diffraction technique is acceptable for the characterization of a composite effluent sample. The advanced statistical technique of multivariate analysis confirmed the interrelationship of the parameters of this complex dispersion system.

In Vitro Evaluation of Cholesterol-Reducing Ability of Chitosan from Mangrove Crab (Scylla serrata) Shell Solid Dispersion using PVP K-30 as a Carrier

Background: Chitosan is a compound that can be synthesized from nature which can reduce the total serum cholesterol levels between 5.8−42.6% and decrease LDL (Low-Density Lipoprotein) between 15.1-35.1%. One of the natural resources containing chitosan derivative compounds is the shell of mud crab. Chitosan is insoluble in water but soluble in acidic solutions such as acetic acid. With such chitosan solubility, it is necessary to increase the solubility by making a solid dispersion system so that drug absorption can be faster. Objectives: The aims of this study is to determine the potential of chitosan solid dispersion system for reducing cholesterol. Material and Methods: The reduction of cholesterol levels was carried out by in vitro tests using UV-Vis spectrophotometer at a wavelength of 405 nm with Lieberman-Burchad reagent. The positive control used was simvastatin. There are 4 formulas, namely SD1, PM1, SD2, and PM2. This solid dispersion system uses polyvinyl pyrrolidone K-30 (PVP K-30) as carrier. Results: The characterization of chitosan has fulfilled all the characterization requirements that is organoleptic (shape and color) was creamy white, moisture content was 2.15%, ash content was 1.14%, ninhydrin test was positive purple, and deacetylation degree was 70.57%. The results of in vitro evaluation were obtained a dark green solution. The reducing percentage in cholesterol levels are SD1: 18.44%; PM1 : 18.11%; SD2 : 29.57%; and PM2 :12.01%. Simvastatin as a positive control has a percentage reduction in cholesterol levels of 30.07%. Conclusion: Chitosan has an activity as anticholesterol agent. SD2 (Solid Dispersion Chitosan: PVP K-30 = 1:2) has the higher percentage than other formulas for reducing cholesterol level comparable with the positive control.