Infertility Diagnosis and Treatment
Sujoy K. Guba in Bioengineering in Reproductive Medicine, 2020
In Contact Thermography temperature sensing is done using liquid crystals. Liquid crystals are materials so named because they have some mechanical properties similar to liquids and at the same time have optical properties shown by crystalline forms in solids. The optical properties include light scattering in symmetrical patterns and frequency selective reflection of light. The properties vary under the influence of temperature. When a film of liquid crystal is illuminated with white light spectral density of light reflected from different regions will depend upon the temperature conditions in that particular region and a color pattern indicative of the temperature of the underlying substrate is seen. Cholesteric liquid crystals are one class of liquid crystals. Cholesterol itself does not have a liquid phase and cholesteric compound are mixed together in specific proportions to manifest color sensitivity in specific ranges. For biological work where temperatures around 37°C are of interests a mixture of cholesteryl chloride, cholesteryl nonanoate and cholesteryl oleyl carbonate can give red (cold) to blue (hot) color change.
Predicting Stability in Rheologically Modified Systems
Laba Dennis in Rheological Proper ties of Cosmetics and Toiletries, 2017
Recently, differential thermal analysis (DTA) has become a practical screen for structural changes in mixtures. Differential scanning calorimetry (DSC) is the form of DTA that is most widely applied, although some applications of differential volume have been fruitful. Differential calorimetry has identified isomorphs of triglycerides in creams, and liquid crystalline mesophases. DSC provides an excellent evaluation method for stress-induced changes, and can even provide an early warning for stability problems. It cannot, however, supplant accelerated stress testing. Phase transitions are easily identified in both quantitative heat energy (latent heat of melting) and temperature of phase change. Liquid crystal phases are easily identified this way.
Advanced Formulation Techniques Including Innovative Materials
Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters in Cosmetic Formulation, 2019
Natural claims and products are no longer a niche market confined to small boutiques and health food stores. Many global companies have added natural lines to their products or minimally natural claims to existing products. National retailers such as Walmart and Target are demanding sustainability trails back to the origin of the feedstock and manufacturing details. Ingredients in personal care are under increased scrutiny via NGOs such as the Environmental Working Group or government watch lists like Proposition 65 in California. One ingredient that is becoming more scrutinized is ethylene oxide, which very generally speaking is used to make oils and waxes more water-soluble. A vast majority of emulsifiers and surfactants in the personal care industry are ethoxylated. BASF recognized the need for natural-based emulsifiers and added to its list of 274 Natural Product Association–certified ingredients with the launch of an exclusive sucrose-based, non-ethoxylated emulsifier: Emulgade Sucro Plus (INCI: sucrose polystearate and cetyl palmitate). This product can serve as a primary emulsifier at higher concentrations or the secondary in lower. It supports the formation of lamellar micelle structure (Figure 18.6 ), that is liquid crystals, which create a unique sensorial experience and have been suggested to lead to better penetration of active molecules. Emulgade Sucro Plus gives formulators a natural option to create luxurious emulsions with high-end consumer appeal.
Ocular lamellar crystalline gels for sustained release and enhanced permeation of resveratrol against corneal neovascularization
Published in Drug Delivery, 2021
Minshu Li, Xiang Yu, Lin Zhu, Yiguang Jin, Zhihong Wu
Lyotropic liquid crystals have recently attracted attention for mucosal drug delivery due to their long retention time at administrated sites and high permeability across biological barriers. Lyotropic liquid crystals have been used as transdermal delivery carriers for the treatment of skin diseases. Mitoxantrone-loaded cubic lyotropic liquid crystal gels have been fabricated for the topical treatment of melanomas (Yu et al., 2016) and capsaicin transdermal cubic crystal gels have been developed to alleviate skin inflammations (Peng et al., 2010). In our preliminary studies, cubic crystals with high viscosity and low resveratrol loading were not suitable for ocular resveratrol delivery. In contrast, lamellar liquid crystals, a type of lyotropic liquid crystals, have suitable fluidity, and high drug loading (Iwata et al., 2004). In this study, we used resveratrol-loaded ocular lamellar crystalline gel (ROLG) for the treatment of CNV.
Transdermal metformin hydrochloride-loaded cubic phases: in silico formulation optimization, preparation, properties, and application for local treatment of melanoma
Published in Drug Delivery, 2019
Xiang Yu, Wei Zhou, Hongmei Wang, Sheng Lu, Yiguang Jin, Junhui Fu
Here, One GMO molecule was firstly divided into Fragments A and B that represented the hydrophilic glycerol and carboxyl group and the hydrophobic long carbon chain, respectively (Supplementary Figure 1). Whereafter, MD simulations were performed in order to obtain the Flory-Huggins parameters (χ) of binary components in all formulations (Luo & Jiang, 2012; Li et al., 2017b). DPD simulations were applied to build the microstructures of all Met/GMO/Ethanol/Water systems according to the Flory-Huggins parameters of binary components. The detailed operation process referred to our previous study (Yu et al., 2018). Finally, the optimized formulation can be screened based on the microstructure and water diffusivity of all liquid crystal systems.
Preparation and evaluation of phytantriol liquid crystal as a liquid embolic agent
Published in Pharmaceutical Development and Technology, 2020
Xiaolin Fang, Aizong Shen
As mentioned above, the in situ liquid crystal prepared in this experiment was mainly used as a liquid embolic agent, so it required a particular liquid property in vitro, but needed to be able to form a liquid crystal gel in vivo. It must be able to effectively embolize the hepatic artery and block blood supply in order to kill cancer cells. The composition selected in this study was a clear and transparent solution in vitro, but a liquid crystal gel, which had excellent gelation characteristics, could be formed in excess water and under the skin of rats. We tested three compositions of PYT: ethanol: H2O, namely 64:16:20, 48:32:20, and 16:64:20 for our research.
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