The present disclosure provides methods for extn. of various agents, e.g. active agent, from a plant source, specifically with the use of extn. formulations which are based on micellar liq. systems. [on SciFinder(R)]
The disclosure concerns viscous or gelled delivery systems based on oily nano-domains dispersed in a viscosified/gelled continuous aq. phase, and suitable for prolonged and/or sustained topical delivery of various active compds. [on SciFinder(R)]
Dendrimer nanostructures are of eminent interest in biomedical applications because of their uniform and well-defined molecular size and shape, and their ability to cross cell membranes and reduce the risk of premature clearance from the human body. Dendrimers perform as gene and drug carriers and have also shown significant therapeutic properties for treating cancer and neurodegenerative diseases. A complex drug delivery system, based on a dendrimer solubilized in the aqueous core of a water-in-oil (W/O) microemulsion (ME) along with the drug may combine the advantages of both dendrimers and MEs to provide better control of drug release. We propose a new microemulsion composed of drug-permitted surfactants and dendrimer that can be used as a potential controlled drug delivery nanosystem. The influence of second generation poly(propyleneimine) (PPI-G2) dendrimer; solubilized in (W/O) ME with a capacity of up to 25 wt% PPI-G2 at various pHs; and their interactions with the surfactant phosphatidylcholine (PC), cosurfactant (butanol), and water was studied. SAXS and EPR measurements indicated that increasing PPI-G2 concentration reduces droplet curvature and increases droplet size thus increasing macro-(SAXS) and micro-(EPR) order degree. Furthermore, SD-NMR and ATR-FTIR show stronger interactions between PPI-G2 and water molecules at the expense of PC and butanol headgroups hydration, which increases microviscosity (EPR). PPI-G2's effect is somewhat opposite to the increasing water phase effect, thus reducing the amount of free water (DSC) and slowing the mobility of all ME components (SD-NMR).[on SciFinder (R)]
Process for extraction and delivery of cannabinoids, using the same medium. Pending in US, EP, Australia, Brazil, Canada, China, Japan, Mexico, New Zealand and Korea. Licensed to a cannabis-based US company
The present work reports on the prepn. and characterization of progesterone-loaded reverse hexagonal (HII) mesophase based on a glycerol monooleate (GMO)/tricaprylin (TAG)/water mixt. for transdermal application. Several compns. into which progesterone was quant. solubilized were selected and used in the present study in order to evaluate the effect of the hormone on structural transitions and characteristics. A GMO/TAG of 90:1 wt ratio with 20 wt% water was found to form HII mesophases with relative high solubilization capacity of 4 wt% progesterone and a shelf life of over one year. The structures were identified by cross-polarized light microscopy (CPLM). Structural confirmations were obtained from small-angle X-ray scattering (SAXS) measurements. The hormone is solubilized at the interface of the HII mesophase as confirmed by SAXS, rheol., FTIR, and DSC. The progesterone, which is loaded onto reverse hexagonal cylinders, leads to strengthening the hydrogen bonding and to better packing of the HII mesophase, suggesting that progesterone is a kosmotropic agent. The reverse hexagonal mesophase seems to be a promising carrier for solubilization of progesterone. [on SciFinder(R)]
Insulin loading into the HII mesophases was examd. as a function of its concn., with addn. of glycerol as a cosolvent and with addn. of phosphatidylcholine (PC) as a structural stabilizer. The structural properties, the mol. interactions, the viscoelastic properties, and the dynamic behavior were investigated by SAXS, ATR-FTIR, and rheol. measurements. Insulin release was then monitored and analyzed. Insulin incorporation into the HII systems shrank the cylinders as it competed with the lipids in water-bonding. Insulin interrupted the interface while increasing $\tau$max and creating a more solid-like response. Upon addn. of PC, cooperative flow behavior was detected, which is probably the reason for increase in insulin cumulative release from 28% to 52% after 300 min. In the presence of glycerol, the system was less cooperative but insulin was more compactly folded, resulting in a slight improvement in insulin release (up to 6%). Addn. of both PC and glycerol caused the max. release (55%). The addn. of additives into the HII system demonstrates how structural modifications can improve insulin release, and influence future design of encapsulated drug delivery systems. [on SciFinder(R)]
NMR chromatog. is a promising and superior alternative to NMR spectroscopy for analyzing mixts. since it simultaneously separates the spectra of the compds. and supplies information about their structure. This implies that there is no need for extn., purifn. or synthesis of stds., that are expensive, time consuming and usually impractical. The main aim of NMR chromatog. is to increase the differences in the diffusivities of different analytes in a mixt., allowing them to be more easily and reliably identified. The selection of surfactants and other components of microemulsions for the best performance as NMR chromatog. media was studied. Attention was focused on the selection of the proper cosolvent in three types of water-dilutable microemulsions: two anionic (deuterated ionic and the previously published fluorinated ionic) and one nonionic (undeuterated Tween-based). The diffusivities of several analytes are compared. The study also examines the effect of diln. and dets. the best compns. for the NMR chromatog. performance. For the anionic microemulsions, 1-butanol was found to be the most promising cosurfactant in the deuterated system 1-butanol-d10:toluene-d8:SDS-d25 in a 6:3:1 wt.-ratio dild. by D2O. This compn., dild. with a 85 wt% D2O, formed a microemulsion that was even stable at relatively elevated temps. (70 °C) and can serve as good medium for chromatog. NMR. Another possibility that was studied consists of nonionic-based microemulsions of iso-Pr alc. (IPA) in IPA:toluene:Tween 20 that could also be easily dild. indefinitely with water. IPA was found to be a very efficient cosurfactant at resolving diffusivities of all the components. However, the lack of availability of deuterated Tween makes it impractical for use as an NMR chromatog. formulation. [on SciFinder(R)]
Omega fatty acids, mainly the triglyceride of docosahexaenoic acid (TG-DHA), are considered important nutraceuticals. These compds. are water-insol. and their transport across membranes depends on their carriers. Dendrimers are known as drug carriers across cell membranes and also as permeation enhancers. The solubilization of TG-DHA and dendrimer into a microemulsion (ME) system serving as a carrier could be used for a targeted delivery in the future. The interactions between TG-DHA and second generation poly(propyleneimine) dendrimers (PPI-G2) and their effect on structural transitions of ME were explored along the water diln. line using ESR and pulsed-gradient spin-echo NMR along with other anal. techniques. The microviscosity, order parameter, and micropolarity of all studied systems decrease upon water diln. Incorporation of TG-DHA reduces the microviscosity, order, and micropolarity, whereas PPI-G2 leads to an increase in these parameters. The effect of PPI-G2 is more pronounced at relative high contents (1 and 5 wt%) where PPI-G2 interacts with the hydrophilic headgroups of the surfactants. In the macroscale, the effects of TG-DHA and PPI-G2 differ mostly in the bicontinuous region, where macroviscosity increases upon TG-DHA incorporation and decreases upon solubilization of 5 wt% PPI-G2. From DSC measurements it was concluded that in the presence of TG-DHA the PPI-G2 is intercalated easily at the interface. [on SciFinder(R)]
Nissim Garti and Rachel. Lutz. 2016. “Double emulsions.” In Encycl. Surf. Colloid Sci. (3rd Ed.), 3: Pp. 1839–1867. CRC Press. Abstract
Double emulsions are emulsions in which an emulsion [water/oil (W/O) or oil/water] is dispersed in a continuous phase (water or oil, resp.), producing W/O/W or O/W/O. These systems have considerable potential in food systems, cosmetics, and pharmaceuticals. This entry reviews some studies and discusses the different approaches that have been introduced. The studies provide better understanding of the stabilizing mechanisms and pathways and a better control of the release patterns from double emulsions. [on SciFinder(R)]
In microemulsions, changes in droplet size and shape and possible transformations occur under various conditions. They are difficult to characterize by most analytical tools because of their nano-sized structure and dynamic nature. Several methods are usually combined to obtain reliable information, guiding the scientist in understanding their physical behavior. We felt that there is a need for a technique that complements those in use today in order to provide more information on the microemulsion behavior, mainly as a function of dilution with water. The improvement of NMR chemical shift measurements independent of bulk magnetization effects makes it possible to study the very weak intermolecular chemical shift effects. In the present study, we used NMR high resolution magic angle spinning to measure the chemical shift very accurately, free of bulk magnetization effects. The chemical shift of microemulsion components is measured as a function of the water content in order to validate the method in an interesting and promising, U-type dilutable microemulsion, which had been previously studied by a variety of techniques. Phase transition points of the microemulsion (O/W, bicontinuous, W/O) and changes in droplet shape were successfully detected using high-accuracy chemical shift measurements. We analyzed the results and found them to be compatible with the previous studies, paving the way for high-accuracy chemical shifts to be used for the study of other microemulsion systems. We detected two transition points along the water dilution line of the concentrate (reverse micelles) corresponding to the transition from swollen W/O nano-droplets to bicontinuous to the O/W droplets along with the changes in the droplets' sizes and shapes. The method seems to be in excellent agreement with other previously studied techniques and shows the advantage of this easy and valid technique. (C) 2014 Elsevier Inc. All rights reserved.
Cholesterol (CH) is a vital mol. for mammalian life. It functions as a precursor for a variety of biol. active mols. and as a moderator of membrane mobility, and has many other essential functions. However, a high blood CH level can cause development of cardiovascular diseases. The soln. for high CH level is an intake of CH-lowering drugs such as statins. Another option for lowering excess CH is intake of phytosterols (PS) as a nutraceutical, which reduces CH absorption in mammals. PS are sterols synthesized only in plants and are structurally similar to CH but with an extra hydrophobic carbon chain at the C-24 position. PS and CH both have low soly. in oil and even lower soly. in water. To improve the efficiency of PS in lowering CH level, it is important to develop suitable vehicles that will improve their solubilization and absorption. In this entry, we examine sterol-solubilization vehicles, which include micelles, emulsions, microemulsions, and bile salt (BS) systems. The discussion focuses on the solubilization capacity (SC) of the vehicles and their effect on the extent of CH absorption/inhibition. It can be concluded that the solubilized PS in these various vehicles enables a significant decrease in CH absorption in comparison to the intake of PS in its solid form. In addn., we shall review the competitive solubilization of CH and PS in microemulsion systems to understand the competitive solubilization mechanism, which has been proposed as one of the mechanisms for PS activity as a CH-lowering agent. [on SciFinder(R)]
This chapter summarizes the authors' efforts to develop modified microemulsions as nano-sized self-assembled liq. vehicles for the solubilization of nutraceuticals and to improve transmembrane transport for addnl. health benefits. Construction of U-type phase diagrams is essential for formulations of water-dilutable microemulsions. The solubilized active mols. are compds. with nutritional value to human health that are used in food applications. The chapter mentions a few such examples, such as lycopene, phytosterols, lutein, toco-pherols, CoQ10 , and essential oils. Some nutraceuticals are known to be practically insol. in water and, therefore, tablets or capsules that are taken orally tend to ppt. once the active ingredient is dild. with water. As a result, the bioavailability is very limited, and the adsorption from the intestine to the blood serum is poorly controlled. Water entrapped at the core of a w/o microemulsion can be bound to the surfactant head group that will restrict the water activity. [on SciFinder(R)]
Docosahexaenoic acid (DHA) promotes synthesis of anti-inflammatory prostaglandins and relief of dry eye symptoms. However, topical ophthalmic application of DHA is difficult because of its lipophilic property. Therefore, it is important to develop aqueous-based formulation with enhanced capabilities. Novel, unique water-dilutable microemulsions (MEs) were constructed to allow loading of naturally occurring rigid long-chain triglyceride of DHA (TG-DHA). The TG-DHA serves as solubilizate and as the oil phase, therefore preparation is poor in oil. The structural transformations of MEs upon water dilution were studied by SAXS, viscosity, electrical conductivity, self-diffusion NMR, DSC, cryo-TEM, and DLS techniques. At low water content a new type of water-in-oil (W/O) structure is formed. The glycerol/water phase hydrates the headgroups of surfactants, and the oil solvates their tails, forming ``ill-defined bicontinuous domains\''\. Upon further water dilution more structured bicontinuous domains of high viscosity are formed. After additional dilution, the mesophases invert to oil-in-water (O/W) droplets of similar to 8 nm. In the structures composed of up to 25 wt% water, the TG-DHA spaces and de-entangles the surfactant tails. Once the bicontinuous structures are formed, the surfactants and TG-DHA content decrease and their interfacial layer shrinks, leading to entanglement and buildup of viscous non-Newtonian mesophase. Above 70 wt% water TG-DHA is embedded in the core of the O/W droplets, and its effect on the droplets' structure is minimal. This new dilutable ill-defined microemulsion can be a potential delivery vehicle for ophthalmic TG-DHA transport. (C) 2015 Elsevier Inc. All rights reserved.
In this study we characterized a new and improved transport vehicle for 2,6-diisopropylphenol (propofol), a hydrophobic anesthesia drug, in the absence and presence of dendrimers being a transporting agents across cells, polypropylenimine (PPI) dendrimer generation 2 (PPI-G2) into a microemulsion (ME). Three unique systems of water-dilutable compositions capable of inverting from W/O to bicontinuous and to O/W structures upon water dilutions were studied by means of electrical conductivity, electron paramagnetic resonance (EPR), and self-diffusion nuclear magnetic resonance (SD-NMR). The microviscosity, as well as the order parameter (from EPR results) increase with the increase in the dendrimer content, while inverting the structures from W/O to bicontinuous ME. Inversion from the bicontinuous mesophase to the O/W nanodroplets caused a very minor increase in the order parameter. Self-diffusion NMR measurements provided information on the diffusivity and the interactions of the different components of the ME. It was found that propofol has no effect on the diffusivity of the components since it is embedded within the core of the ME droplets. However, the dendrimer increases the diffusivity of water. In addition, we learned that at high dendrimer content, it remains solubilized; however its location at the ME/water interface moves to the water continuous phase. The study demonstrates the ability of water dilutable MEs to act as drug carriers hosting both propofol and dendrimer. (C) 2016 Elsevier B.V. All rights reserved.