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Interfacial Catalysis at Oil/Water Interfaces
Published in Alexander G. Vdlkdv, Interfacial Catalysis, 2002
Catalyst separation or cost will usually be the main factor rather than the structureactivity relationshps for the choice of a specific PEG ether or crown ether. In contrast to quaternary onium salts, crown compounds are thermally and chemically more stable. Their application is limited mainly by the high cost and toxicity. 18-Crown-6 and its derivatives have become available in ton quantities and in various grades of purity. The commercial application of crown ethers will be more feasible due to their reduced cost and their high reactivity. The PEGs and their capped ethers are more stable than quaternary ammonium salts and are attractive for processes using an excess of the PEGs due to their lowest cost and least toxicity. PEG derivatives are generally included in standard screening programs for industrial processes, e.g., PEG 400 is always considered for hydroxide-promoted PTC reactions. PEGs and TDA-1 are inexpensive, thermally stable in the absence of strong acids, usually easy to remove and recover, nontoxic, easily biodegradable, and commercially available. Based on the yield and rate data of the displacement of chloride from benzyl chloride by acetate ion, so called the standard reaction for catalyst evaluation, several crown ethers, aminopolyethers, and cryptands, etc., were evaluated [108].
Design and optimization of liquisolid compact based vaginal sustained release tablet of antifungal agent for vaginal candidiasis
Published in Journal of Dispersion Science and Technology, 2022
Pranita S. Kanojiya, Pradip N. Ghodake, Rita N. Wadetwar
The amount of Lawsone in AVF pH 4.1 had good linearity (R2=0.997) against the concentration range of 10–80 μg/mL that showed to obey the Beer-Lambert’s law. The regression equation had the slope and intercept values of 0.11 and −0.013 respectively. The solubility of Lawsone in distilled water, Tween 80, Transcutol P, Glyerol, Propylene glycol, PEG 400 was found to be 37.03, 36.92, 21.36 and 6.57 mg/mL respectively as shown in Figure S1. The drug solubilization into the solvent is a prerequisite for the liquisolid compact tablet. Therefore, it is imperative to know the best solubilizer for the liquid medication preparation. The maximum solubility was exhibited by Transcutol P followed by PEG 400, Glycerol and finally Tween 80. The higher the drug is soluble in the nonvolatile solvent, means more amount of drug is incorporated into the liquisolid tablet through the adsorption that in turn helps in higher dissolution rate. PEG 400 was further used in the preliminary trial batches as the tablets made with Transcutol P showed the oozing out of the liquid medication which was not the case with PEG 400. Hence for further final batch preparation of tablets, the liquid medication was formulated using PEG 400. This solvent is widely used as the cosolvent for the improvement of the aqueous solubility of the poorly soluble drugs. Lawsone being a poorly soluble drug got solubilized in the selected solvent.
Development of nanoemulsion gel based formulation of terbinafine for the synergistic antifungal activity: Dermatokinetic experiment for investigation of epidermal terbinafine deposition enhancement
Published in Inorganic and Nano-Metal Chemistry, 2021
Prabhu Raut, Shobhit Kumar, Babar Iqbal, Javed Ali, Sanjula Baboota
Co-surfactant plays a very important role in reducing the interfacial tension as they fit themselves into void space of surfactant molecule. Selection of co-surfactant was done on the basis of miscibility studies with selected oil and surfactant. Table 5 lists the miscibility data of co-surfactant with tea tree oil and tween 20. Co-surfactant like Plurol Oleque CC497, lauroglycol and transcutol P showed phase separation/turbidity in miscibility study. Only PEG 400 exhibited miscibility with tea tree oil as well as tween 20 hence it was selected on the basis of above criteria. PEG 400 is a low-molecular-weight grade of polyethylene glycol. It is hydrophilic, clear, colorless, and viscous liquid. It is widely used in pharmaceutical formulations. It improves drug solubility in vesicle dispersion and avoids precipitation of drug. It has good penetration properties, which makes it an excellent component as drug carrier for skin delivery.[27]
Ionic Liquid Additives for Mixed and Elastohydrodynamic Lubrication
Published in Tribology Transactions, 2018
Shuyan Yang, Janet S. S. Wong, Feng Zhou
In this study, polyethylene glycol PEG-400 (PEG), with average molecular weight of 400 g mol−1, was used as the base fluid. Metal salt LiTFSI was purchased and used as received. Their molecular structures are shown in Fig. 1. IL additives are synthesized in situ based on the formation of complexes between lithium salts and organic compounds with an acylamino group when they are mixed at a specific molar ratio (Yoshida, et al. (32)), giving rise to complexes with physicochemical properties similar to those of conventional ILs. Based on this principle, an LiTFSI-based IL, [Li(glyme)]TFSI, was prepared as an in situ coordinating lubricant additive or in situ ionic liquid additive by dissolving LITFSI in PEG (see Fig. 1c).