Oil-soluble Substances Research Articles

Crystallization-driven formation poly (l-lactic acid)/poly (d-lactic acid)-polyethylene glycol-poly (l-lactic acid) small-sized microsphere structures by solvent-induced self-assembly

Improving hydrophobicity through the regulation of surface microstructures has attracted significant interest in various applications. This research successfully prepared a surface with microsphere structures using the Non-solvent induced phase separation method (NIPS). Poly(D-Lactic acid)-block-poly(ethylene glycol)-block-poly(D-Lactic acid) (PDLA-PEG-PDLA) block polymers were synthesized by ring-opening polymerization of D-Lactic acid (D-LA) using polyethylene glycol (PEG) as initiator. PLLA/PDLA-PEG-PDLA membrane with microscale microsphere morphology was fabricated using a nonsolvent-induced self-assembly method by blending the triblock copolymer with a poly(L-lactic acid) (PLLA) solution. In phase separation processes, the amphiphilic block copolymers self-assemble into micellar structures to minimize the Gibbs free energy, and the hydrophilic segments (PEG) aggregate to form the core of the micelles, while the hydrophobic segments (PDLA) are exposed on the outer corona resulting in a core-shell structure. The Stereocomplex Crystalline (SC), formed by the hydrogen bonding between PLLA and PDLA, can facilitate the transition from liquid-liquid phase separation to solid-liquid phase separation, and the PEG chain segments can enhance the formation of SC. The membrane, prepared by adjusting the copolymer content and PEG chain length, exhibited adjustable microsphere quantity, diameter, and surface roughness, enabling excellent hydrophobicity and controlled release of oil-soluble substances.

Improving the Treatment Effect of Carotenoids on Alzheimer's Disease through Various Nano-Delivery Systems.

Natural bioactive compounds have recently emerged as a current strategy for Alzheimer's disease treatment. Carotenoids, including astaxanthin, lycopene, lutein, fucoxanthin, crocin and others are natural pigments and antioxidants, and can be used to treat a variety of diseases, including Alzheimer's disease. However, carotenoids, as oil-soluble substances with additional unsaturated groups, suffer from low solubility, poor stability and poor bioavailability. Therefore, the preparation of various nano-drug delivery systems from carotenoids is a current measure to achieve efficient application of carotenoids. Different carotenoid delivery systems can improve the solubility, stability, permeability and bioavailability of carotenoids to a certain extent to achieve Alzheimer's disease efficacy. This review summarizes recent data on different carotenoid nano-drug delivery systems for the treatment of Alzheimer's disease, including polymer, lipid, inorganic and hybrid nano-drug delivery systems. These drug delivery systems have been shown to have a beneficial therapeutic effect on Alzheimer's disease to a certain extent.

Pickering emulsions co-stabilised by cellulose nanofibres and nicotinamide mononucleotide

Emulsified solid particles adsorbed at the oil–water interface can stabilise Pickering emulsions by acting as a physical barrier to the coalescence of oil droplets. Cellulose nanofibres (CNFs) have been used in food-grade Pickering emulsions because of their excellent performance as a low cost and sustainable material. Nicotinamide mononucleotide (NMN) is a small-molecule zwitterion with polar functionality capable of interacting with the CNFs. The ability of cationic CNFs and NMN to co-stabilise sunflower oil Pickering emulsions was investigated under various conditions using methods such as contact angle measurement, creaming stability, rheology, microscopy, thermal stability, and water-holding capacity. Emulsions with ultra-high stability, good gelation, and high plasticity were obtained using single-step shear dispersion with 0.25 wt% CNFs, 0.05–0.3 wt% NMN, and near-neutral pH. NMN stabilised the oil–water interface through electrostatic interactions and hydrogen bonding with CNFs. NMN transferred into the aqueous phase and interacted with CNFs to form a complex with a three-dimensional network structure, which improved the bulk viscosity and steric hindrance of the emulsion and created more compact adsorption of CNFs at the oil–water interfaces. Overall, the synergistic effects of various factors allow NMN to effectively co-stabilise Pickering emulsions with CNFs, making it an exciting method that can be used to encapsulate oil-soluble substances.

Alginate-gelatin emulsion droplets for encapsulation of vitamin A by 3D printed microfluidics

Microfluidics is characterized by the manipulation of fluids in submillimeter channels and has great application potential in encapsulation. To further extend the application of microfluidics in food industries, a 3D printed microfluidic device is used to encapsulate vitamin A and improve its stability. Two natural macromolecules, sodium alginate and gelatin, are added to water as the continuous phase to generate monodisperse emulsion. Under different flow rate ratios, the diameter of droplets decreases with the increase of continuous flow rate. However, at the same flow rate ratio, varying the dispersed and continuous flow rates does not significantly change the diameter and size distribution of emulsion collected. The prepared O/W (oil/water) single emulsion can form microgel particles and avoid degradation of vitamin A by simulated gastric acid; the encapsulated vitamin A will not be released until particles reach simulated intestinal tract. In the simulated digestion in vitro, no vitamin A is released for 2 h in the acidic environment; under an alkaline or neutral environment such as those in intestinal fluids, vitamin A can be released from the microgel particles within 2.5 h. Using the presented approach, emulsions encapsulating vitamin A have been prepared and can potentially be applied to encapsulate other oil-soluble substances in the food industry.

Микроэмульсии и лиотропные жидкие кристаллы лецитина как системы для трансдермальной доставки лекарственных веществ

Reverse microemulsions in the system lecithin – oleic acid – aseline oil – avocado oil – tea tree essential oil – water and lamellar liquid crystals in the system lecithin – avocado oil – tea tree essential oil – water were studied as systems for transdermal drug delivery. Oil– and water-soluble substances, as well as substances poorly soluble in water and oil in the form of particles of a solid phase, can be introduced into the liquid crystals in concentrations of a few percent. In the reverse microemulsions it is possible to introduce oil-soluble substances in concentrations of a few percent and water-soluble substances in concentrations of tenths of a percent. The dialysis method showed that the rate of release of water-soluble substances from the reverse microemulsion containing 4.8 wt.% water is about 2.5 times higher than that from the lamellar liquid crystal, which contains 15 wt. % water. This is explained by the fact that viscosity of the liquid crystal is more than 100 times higher than viscosity of the microemulsion.

Microemulsions and Lyotropic Liquid Crystals of Lecithin as Systems for Transdermal Drug Delivery

Reverse microemulsions in the lecithin–oleic acid–paraffin oil–avocado oil–tea tree essential oil–water system and lamellar liquid crystals in the lecithin–avocado oil–tea tree essential oil–water system were studied as systems for transdermal drug delivery. Oil- and water-soluble substances, as well as substances that are poorly soluble in water and oil in the form of solid-phase particles, can be introduced into liquid crystals in concentrations of a few percent. Oil-soluble substances can be introduced into reverse microemulsions in concentrations of a few percent and water-soluble substances can be introduced in concentrations of tenths of a percent. The dialysis method showed that the rate of release of water-soluble substances from the reverse microemulsion containing 4.8 wt % water is approximately 2.5 times higher than that from the lamellar liquid crystal containing 15 wt % water. This is explained by the fact that the viscosity of liquid crystals is more than 100 times higher than the viscosity of microemulsions.

Predictive performance and inter-laboratory reproducibility in assessing eye irritation potential of water- and oil-soluble mixtures using the Short Time Exposure test method

The Short Time Exposure (STE) test method is an alternative method for assessing eye irritation potential using Statens Seruminstitut Rabbit Cornea cells and has been adopted as test guideline 491 by the Organisation for Economic Co-operation and Development. Its good predictive performance in identifying the Globally Harmonized System (GHS) No Category (NC) or Irritant Category has been demonstrated in evaluations of water-soluble substances, oil-soluble substances, and water-soluble mixtures. However, the predictive performance for oil-soluble mixtures was not evaluated. Twenty-four oil-soluble mixtures were evaluated using the STE test method. The GHS NC or Irritant Category of 22 oil-soluble mixtures were consistent with that of a Reconstructed human Cornea-like Epithelium (RhCE) test method. Inter-laboratory reproducibility was then confirmed using 20 water- and oil-soluble mixtures blind-coded. The concordance in GHS NC or Irritant Category among four laboratories was 90%–100%. In conclusion, the concordance in comparison with the results of RhCE test method using 24 oil-soluble mixtures and inter-laboratory reproducibility using 20 water- and oil-soluble mixtures blind-coded were good, indicating that the STE test method is a suitable alternative for predicting the eye irritation potential of both substances and mixtures.

Simultaneous Electrochemical Determination of Vitamin K1 and Vitamin D3 by using Poly (Alizarin Red S)/Multi-walled Carbon Nanotubes Modified Glassy Electrode

Background: The goal of this research is to develop a new electroanalytical procedure for the simultaneous electrochemical detection of vitamin K1 (VK1) and vitamin D3 (VD3), in a sodium dodecyl sulfate (SDS) -containing buffer solution, with no detectable interference of other kinds of vitamin A and vitamin E present in the sample solution. Surfactant solutions are well known their capability to dissolve oil-soluble substance such as dyes, hydrocarbons, esters, perfumes, and so on. Micellar solubilization is the powerful alternative for the dissolution of poorly soluble or hydrophobic compounds in aqueous environments. Surfactants micellar media can be successfully applied for the solubilization of lipophilic organic compounds in water media and enhancement of their electrochemical activity. In this research, the anionic surfactant SDS was used as the solubilizing agent. Keywords: Vitamin K1, vitamin D3, simultaneous determination, voltammetry, alizarin red S, carbon nanotube, food analysis.

Experience with the HET-CAM Method in the Routine Testing of a Broad Variety of Chemicals and Formulations

Data on eye irritation are generally needed for the hazard identification of chemicals. For the routine testing of a broad variety of chemicals and formulations, we have used the Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) method. In the course of a tiered-testing strategy, and due to the lack of global regulatory acceptance of the HET-CAM method, we have also performed the Rabbit Eye Irritation test according to OECD Test Guideline 405. Of the 145 substances tested, 76% were classified as non-irritant/mild irritant and 13% were identified as irritant in vivo, according to the EU classification system (61% and 28%, respectively, with the GHS classification). The remaining 11% were severe irritants in vivo, based on the irreversibility of the effects and not due to sufficiently high irritation scores in the three days following application. The retrospective analysis revealed that the overall accuracy of the HET-CAM assay was 65% and the overall rates of false-negatives (FN) and false-positives (FP) were 50% and 33%, respectively. The HET-CAM assay was sufficiently specific (few FP) for water-soluble substances, but failed to identify nearly all the severe irritants within this group. In contrast, it was highly sensitive (no FN) for non-soluble and oil-soluble substances, but the specificity for this group was rather low. Therefore, we conclude that the HET-CAM assay is not useful in our tiered-testing strategy for eye irritation testing. However, for water-insoluble substances, it might be applicable in combination with another in vitro method, provided that regulatory acceptance is gained.

Development of a New Preparation Method of Liposomes Using Supercritical Carbon Dioxide

A new method, the supercritical reverse phase evaporation method, for the preparation of liposomes in one step using supercritical carbon dioxide without any organic solvent toxic to the human body has been developed. This method allowed aqueous dispersions of liposomes to be obtained through emulsion formation by introduction of a given amount of water into a homogeneous mixture of supercritical carbon dioxide/l-α-dipalmitoylphosphatidylcholine/ethanol with sufficient stirring and subsequent pressure reduction. Transmission electron microscopy observations using the freeze-replica method on the obtained vesicles revealed that most of them are large unilamellar liposomes with diameters of 0.1−1.2 μm. The trapping efficiency of the liposomes examined with the d-(+)-glucose indicated more than 5 times higher trapping efficiency for the water-soluble solute than that of multilamellar vesicles prepared by the Bangham method. The trapping efficiency for cholesterol, an oil-soluble substance, of the liposomes was 63%. These results showed that the supercritical reverse phase evaporation method is an excellent technique that permits one-step preparation of large unilamellar liposomes with a high trapping efficiency for both water-soluble and oil-soluble substances.

Adsorption of Surfactants

The thermodynamic equations were summarized for the adsorption of surfactants and surfactant mixtures from monomeric and micellar solution to the air/water and oil/water interfaces. The phase diagrams of adsorption and micelle formation were introduced and discussed for some examples such as ideal mixing, and nonideal mixing showing negative azeotrope and heteroazeotrope. Also the thermodynamic quantity changes associated with adsorption were shown and the effect of a coexistent oil phase was examined briefly. Furthermore the results of the adsorption of oil-soluble substances from an oil phase and the finding of the phase transition of adsorbed films were introduced.

Preliminary Communication: Treatment of irritant contact dermatitis in workmen with perfluoropolymethylisopropyl ether (Fomblin HC)

Synopsis Non-allergic contact dermatitis is a major dermatological problem for the workmen of an important factory which manufactures industrial machines (SAIMP SpA) located at Padua. Such dermatitis is due to the presence in the environment of paints, solvents, surfactants, lubricants and metal powders (steel and cast-iron). As medical treatment, the factory doctor practises the use of common barrier creams which do not give completely satisfactory results. To cope with this problem, some workmen were treated with preparations containing Fomblin HC. The highly successful results of this new type of treatment are reported: among other findings this study shows, through experimental evidence, that Fomblin HC has a protective effect not only against water soluble substances but also against oil soluble substances (in fact, the latter are probably the main cause of contact dermatitis contracted by these workmen).

Solubilization by polymer/polymer complexes

Water-soluble complexes of nonionic polymers and polymeric acids solubilized an oil-soluble dye (Yellow OB) dependent on the nature of both polymers, their mixing ratio and pH. This occurred markedly in low-foaming solutions of poly (propylene oxide) and poly (methacrylic acid) in unit mole mixing ratios about 1–3 in excess of the nonionic polymer, and the extent of solubilization of the dye was compared with the solubilization by a dilute nonionic surfactant solution. The complexes are supposed to possess hydrophobic domains which are able to incorporate oil-soluble substances.

Studies on the Behavior of Natural Surfactant at the Oil-Water Interface. II. Behavior of Natural Surfactant at the Oil-Water Interface

Abstract The behavior of natural surfactants was studied at an oil-water interface by measurement of the interfacial tension and the observation of the oil-water interface. Lecithin was used as an oil-soluble substance and sodium cholate was used as a water-soluble substance; n-paraffin, corn oil, unsaturated fatty acid and fatty alcohol were used as an oil phase. The reduction of interfacial tension was greatest in a dodecane-sodium cholate solution system, but the minimum interfacial tension was observed in an oleic acid-sodium cholate solution system. Spontaneous emulsification occurred in the oil phase when oleic acid was left in contact with sodium cholate solution. The most remarkable change was found in the system of oleic acid in contact with sodium cholate solution, in which crystal of cholic acid were formed at the interface.

Precipitation of nonionic surfactant-polymeric acid complexes solubilizing oil-soluble substances

The complex formed between the polyoxyethylene-type nonionic surfactant and polycarboxylic acid in aqueous solution has a solubilization ability different from that of the surfactant alone. As the complex is precipitated by the addition of acid or salt, so is the complex containing a solubilized oil-soluble substance. The complexes of the nonionic surfactant and polyacrylic or polymethacrylic acid containing solubilized yellow OB, azobenzene, or naphthalene were precipitated almost intact. The solubilizates in the dried matrix of the complexes were hardly extractable with such solvents as benzene, carbon tetrachloride, and n-hexane, and therefore, it is considered that the solubilizates are contained in a cross-linked structure of multiple hydrogen bonds between the polyoxyethylene chain of the surfactant and polycarboxylic acid.

Studies of Spontaneous Emulsification. II. The Effect of Nonionic Surfactants

Abstract At the oil/water interface, spontaneous emulsification occurs when oil containing certain oil-soluble substances such as cholesterol is allowed to stand in contact with aqueous nonionic surfactant solutions. In this study, the interfacial tension between oil and water phases was measured in the presence of various oil-soluble substances, such as cholesterol, 1-dodecanol, and cis-9-octadecene-1-ol, added as ingredients in oil and various nonionic and anionic surfactants added in water, this study ascertained their effects on the emulsification.

Electron spin resonance measurements of molecular interactions in mouse olfactory epithelium

THE mechanism by which molecules interact with, and so stimulate, the surfaces of olfactory receptor cells has given rise to much speculation. Since oil-soluble substances are often very effective odours, it has been proposed that olfactory transduction occurs when an odorant molecule perturbs the lipids of the sensory membranes. Conversely, the known steric aspects of odorant molecule interactions argue for a more specific binding for which a protein would be a more suitable receptor1–4.

The solubilizing properties of the protein-detergent complex

Solubilization of oil-soluble substances, not observed in sodium alkyl sulfate solutions below the critical micelle concentration, does occur if protein is present in the detergent solutions. The extent of solubilization was studied as a function of detergent concentration, pH, salt concentration, carbon chain length of detergent, and the structure of the dyes used. The protein detergent complex, and not an altered protein, was responsible for the solubilization of oil-soluble dyes in alkyl sulfate solutions below the critical micelle concentrations of these detergents. These experiments suggested that the form of the detergent on the protein was that of a small aggregate which had properties similar to micelles that exist above the critical micelle concentrations of pure detergent solutions.

鉱油の冷却曲線の総合的考察について

Investigating inclusively the beginning curves for all kinds of mineral oils, the approximate calculation method of quenching properties was explained without measuring the quenching curves. Addition of the oil soluble substances of high molecular weight and surfactant agents particularly improved the quenching properties.When the initial temperature of test pieces is T°C, the later temperature t°C, and the time τsec., the formula of quenching curves are as follows:At (I) t+T-T1/τ1τ=TAt (II), (III) (τ-τ1) tk1=k2or (t-te)τn1=n2but k1, k2, n1 and n2 are constant, and te is the temperature when the oil temperature is idential with the metal temperature.

Induction and maintenance of decidual changes with progesterone and estrogen.

THE presence of the corpus luteum during pregnancy led Born, and later Fraenkel (1, 2), to investigate the influence of the corpus luteum on the implantation of the embryo. Ancel and Bouin (3) showed that the corpus luteum induced progestational changes in the endometrium of the rabbit. These findings were confirmed by other workers and climaxed by Corner and Allen (4) with the extraction of an oil-soluble substance from corpora lutea which would induce these progestational changes in the uterus of ovariectomized rabbits. They called the extracted material, progestin, a substance necessary for gestation. Since that time the crystalline hormone, progesterone, has become readily available for clinical use and favorable results have been reported in cases of threatened abortion. In the early clinical studies, ten to twelve years ago, progesterone was available for use in doses of only 1 to 5 mg. per day. Since that time the supply of progesterone has become so plentiful that doses as high as 100 mg. per day ...