Microstructure evaluation of dermally applicable liquid crystals as a function of water content and temperature: Can electron paramagnetic resonance provide complementary data?

Publication date: 30 November 2017 Source:International Journal of Pharmaceutics, Volume 533, Issue 2 Author(s): Mirjam Gosenca Matjaž, Janez Mravljak, Marija Bešter Rogač, Marjeta Šentjurc, Mirjana Gašperlin, Alenka Zvonar Pobirk Insight into the microstructure of lyotropic liquid crystals (LCs) is of crucial importance for development of novel dermal delivery systems. Our aim was to evaluate the phase behaviour of dermally applicable LCs composed of isopropyl myristate/Tween 80/lecithin/water, along the dilution line, where phase transitions are predominantly driven by increased water content. Additionally, identification of LC temperature dependence is of great importance for skin application. Selected LCs were evaluated using electron paramagnetic resonance (EPR) plus conventionally used methods of polarization microscopy, small-angle X-ray scattering, differential scanning calorimetry, and rheological measurements. Depending on water content, LCs formed diverse microstructures, from (pseudo)hexagonal (LC1) and lamellar (LC2-LC7) liquid crystalline phases that possibly co-exist with rod-like micelles (LC4-LC7), to a transitional micellar phase (LC8). Furthermore, the LCs microstructure remained unaltered within the tested temperature range. EPR was shown to detect microstructural transitions of LCs and to provide complementary data to other techniques. These data thus confirm the applicability of EPR as a complementary technique for better understa...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research

Related Links:

In this study, the laser surface heat treatment of a rotating cylindrical work-piece was investigated using both experimental and numerical modeling approaches, with an aim to correlate and predict the temperature distribution during the process. The depth of the laser affected zone was predicted by solving the transient heat transfer with a moving laser heat source, using finite element analysis. The temperatures derived from the microstructural examination of the experimental specimen were found to closely agree with the predicted results from the numerical simulations. The numerical and experimental results have also le...
Source: Journal of Materials Processing Technology - Category: Materials Science Source Type: research
In this report, we show some examples of anatomo-functional connectivity matrices, and associated directional maps. We also indicate how CCEP features, especially latencies, are related to spatial distances, and allow estimating the velocity distribution of neuronal signals at a large scale. Finally, we describe the impact on the estimated connectivity of the stimulation charge and of the contact localization according to the white or gray matter. The most relevant maps for the scientific community are available for download on f-tract. eu (David et al., 2017) and will be regularly updated during the following months with ...
Source: NeuroImage - Category: Neuroscience Source Type: research
Publication date: 1 January 2019Source: Food Chemistry, Volume 270Author(s): Rodrigo Melgosa, Óscar Benito-Román, María Teresa Sanz, Esther de Paz, Sagrario BeltránAbstractParticles from Gas-Saturated Solutions (PGSS)-drying has been used as a green alternative to encapsulate omega–3 polyunsaturated fatty acids (n–3 PUFAs) at mild, non-oxidative conditions. PGSS-dried particles have been compared to those obtained by conventional drying methods such as spray-drying and freeze-drying, finding encapsulation efficiencies (EE) up to 98% and spherical morphology for PGSS- and spray-dried ...
Source: Food Chemistry - Category: Food Science Source Type: research
Publication date: 1 January 2019Source: Food Chemistry, Volume 270Author(s): Mudasir Ahmad, Priti Mudgil, Adil Gani, Fathalla Hamed, F.A. Masoodi, Sajid MaqsoodAbstractNovel starch-based nanoparticles from three sources: horse chestnut (HSC), water chestnut (WSC) and lotus stem (LSC) were prepared for nano-encapsulation of catechin. Average particle size of HSC, WSC and LSC based nano-particles were 322.7, 559.2 and 615.6 nm with encapsulation efficiency of 59.09, 48.30, and 55.00% and negative zeta potential of −18.05, −21.5 and −18.05 mv, respectively. Structural, physical and thermal properties wer...
Source: Food Chemistry - Category: Food Science Source Type: research
Publication date: 1 January 2019Source: Food Chemistry, Volume 270Author(s): K.B. Akshaya, Anitha Varghese, Y.N. Sudhakar, Louis GeorgeAbstractNanoclusters of Ir were electrochemically deposited on carbon fiber paper (CFP) substrate modified with poly(3,4-ethylenedioxythiophene) (PEDOT), a conducting polymer between the potential range 0.0 V and 0.6 V at 0.05 V/s scan rate. The electrocatalytic activity of Ir–PEDOT/CFP electrode towards oxidation of morin, a flavonoid was significantly greater than that of PEDOT/CFP and bare CFP electrodes. Factors affecting the anodic peak of morin namely, effect of pH, scan r...
Source: Food Chemistry - Category: Food Science Source Type: research
Publication date: Available online 17 July 2018Source: Veterinary MicrobiologyAuthor(s): Briana Petruzzi, Rami A. Dalloul, Tanya LaRoith, Nicholas P. Evans, F. William Pierson, Thomas J. InzanaAbstractPasteurella multocida is the causative agent of avian cholera, an important economic and ecological disease that can present as a peracute, acute, chronic, or asymptomatic infection. Acute avian cholera is associated with encapsulated P. multocida, while chronic and asymptomatic cases of avian cholera may be associated with capsule-deficient P. multocida isolates. We hypothesize that biofilm formation is important for chronic...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
Publication date: Available online 17 July 2018Source: Biocatalysis and Agricultural BiotechnologyAuthor(s): Sathish Sundararaman, V. Kavitha, Achu Joby Mathew, Sreya Mariya SebyAbstractThe decolourization efficiency of azo dye, Congo red was examined by heterogeneous Fenton reaction using different support like zeolite, activated carbon and fly ash. The iron catalyst was coated into the support by wet impregnation method. Among different support system, zeolite supported iron catalyst (Fe-Z) exhibited maximum decolourization which was used for further studies. The prepared catalyst (Fe-Z) was characterized by scanning ele...
Source: Biocatalysis and Agricultural Biotechnology - Category: Biotechnology Source Type: research
This study reports an experimental investigation into the chemical kinetics of several commercial pyrotechnic compositions. A differential scanning calorimeter was utilized to elucidate the thermo-kinetic characteristics of five multicomponent pyrotechnic compositions. The multicomponent nature of practical pyrotechnics results in a complex interaction between the various components as well as condensed phase reactions. The thermo-kinetic study was carried out to approximate the heating experienced by the pyrotechnics before the combustion zone. The chemical kinetic parameters such as overall activation energy (Ea) and pre...
Source: Thermochimica Acta - Category: Chemistry Source Type: research
Publication date: Available online 17 July 2018Source: Thermochimica ActaAuthor(s): Jun Deng, Li-Feng Ren, Li Ma, Chang-Fui Lei, Gao-Ming Wei, Wei-Feng WangA B S T R A C TLow-temperature exothermic oxidation characteristics of pulverized sub-bituminous coal was investigated using differential scanning calorimetry system in atmospheres where the oxygen concentrations were 21, 17, 13, 9, and 5 vol. %, respectively. The results indicate that the heat flow gradually decreases after it reaches the maximum value. A decreased oxygen concentration had a delaying effect on the heat flow and derivative of heat flow curves. A ...
Source: Thermochimica Acta - Category: Chemistry Source Type: research
Publication date: 1 May 2018Source: Journal of Energy Chemistry, Volume 27, Issue 3Author(s): A.M. Patil, A.C. Lokhande, P.A. Shinde, J.H. Kim, C.D. LokhandeAbstractIn present work, the vertically aligned NiS nano-flakes composed thin film is prepared by anionic exchange process in which hydrothermally prepared Ni(OH)2 is used as a parent thin film and Na2S as a sulfide ion source. This synthesis process produced fully transformed and shape-controlled nano-flakes of NiS from nano-flowers of Ni(OH)2. The electrochemical supercapacitor properties of NiS electrode are studied with cyclic voltammetry (CV), galvonostatic charge...
Source: Journal of Energy Chemistry - Category: Chemistry Source Type: research
More News: Dermatology | Drugs & Pharmacology | Lecithin | PET Scan | Skin | Study